technical white paper for ip

HUAWEI SE2900 Session Border Controller V300R002C10

Technical White Paper for IP

Issue 01

Date 2016-01-15

HUAWEI TECHNOLOGIES CO., LTD.

Issue 01 (2016-01-15) Huawei Proprietary and Confidential

Copyright © Huawei Technologies Co., Ltd.

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Copyright © Huawei Technologies Co., Ltd. 2016. All rights reserved.

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HUAWEI SE2900 Session Border Controller

Technical White Paper for IP About This Document



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About This Document

Purpose

This document briefly describes the IP functions and networking solutions provided by

Huawei SE2900 Session Border Controller, involving IP-related features, networking,

networking reliability, and typical configuration examples.

This document helps engineers understand how to deploy the SE2900 on carriers' networks.

Intended Audience

This document is intended for:

Carrier managers and planning and design engineers

Huawei sales and marketing staff

Technical support engineers

Maintenance engineers

Symbol Conventions

The symbols that may be found in this document are defined as follows.

Symbol Description

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avoided, will result in death or serious injury.

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avoided, could result in death or serious injury.


avoided, may result in minor or moderate injury.


avoided, could result in equipment damage, data loss,

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NOTICE is used to address practices not related to personal

injury.


Technical White Paper for IP About This Document



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Symbol Description

Calls attention to important information, best practices and

tips.

NOTE is used to address information not related to personal

injury, equipment damage, and environment deterioration.

Change History

Changes between document issues are cumulative. The latest document issue contains all the

changes made in earlier issues.

Issue 01 (2016-01-15)

This issue is used for a first office application (FOA) site.


Technical White Paper for IP Contents



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Contents

About This Document .................................................................................................................... ii

1 Overview ......................................................................................................................................... 1

1.1 IP Service Overview ..................................................................................................................................................... 1

1.2 VRF Service Overview ................................................................................................................................................. 3

2 IP Networking Features ............................................................................................................... 5

2.1 Overview ...................................................................................................................................................................... 5

2.2 Port ............................................................................................................................................................................... 5

2.3 Interface ........................................................................................................................................................................ 6

2.4 Eth-trunk ....................................................................................................................................................................... 6

2.5 IPv4 Address ................................................................................................................................................................. 9

2.6 IPv6 Address ............................................................................................................................................................... 10

2.7 IPv4/IPv6 Dual Stack .................................................................................................................................................. 14

2.8 IP Routing ................................................................................................................................................................... 14

2.9 VRF/VRF6 .................................................................................................................................................................. 15

3 Networking Reliability .............................................................................................................. 17

3.1 Active/Standby Processes ........................................................................................................................................... 17

3.2 Active/Standby Ports................................................................................................................................................... 18

3.3 Load Balancing ........................................................................................................................................................... 18

3.4 Active/Standby Routes ................................................................................................................................................ 19

3.5 ARP Probe .................................................................................................................................................................. 19

3.6 IPv6 Neighbor Discovery ........................................................................................................................................... 19

3.7 BFD ............................................................................................................................................................................ 20

4 Networking Solutions ................................................................................................................ 22

4.1 Overview .................................................................................................................................................................... 22

4.2 Port Classification ....................................................................................................................................................... 23

4.3 Dual-plane Load Balancing Networking .................................................................................................................... 26

4.4 Dual-plane Load Balancing Networking Using Eth-Trunk Interfaces ........................................................................ 36

4.5 Single-plane Load Balancing Networking Using Eth-Trunk Interfaces ..................................................................... 48

4.6 Active/Standby Networking ........................................................................................................................................ 59

4.7 Interconnection with VRRP-enabled Routers ............................................................................................................. 68

4.8 IPv6 Networking ......................................................................................................................................................... 77


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4.9 VRF Networking ........................................................................................................................................................ 79

5 Networking Limitations ............................................................................................................ 80

5.1 Port ............................................................................................................................................................................. 80

5.2 IPv4 Address ............................................................................................................................................................... 80

5.3 IPv6 Address ............................................................................................................................................................... 80

5.4 Routing ....................................................................................................................................................................... 80

5.5 BFD ............................................................................................................................................................................ 80

Acronyms and Abbreviations ...................................................................................................... 82


Technical White Paper for IP 1 Overview



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1 Overview

1.1 IP Service Overview

The SE2900 is an SBC that participates in the implementation of solutions, such as VoBB,

RCS, VoLTE, convergent conference, NGN, and one network. The SE2900 is deployed at the

border of different parts of an IP network or at the border of different IP networks to control

voice, video, and data sessions. The functions of the SE2900 include access control, security,

QoS, media transcoding, media firewall, media/signaling proxy, NAT traversal, firewall

traversal, flexible routing, network redundancy, and encrypted transmission of

signaling/media.

Figure 1-1 shows the networking in which the SE2900s are interconnected with other devices

using IP-based media and signaling channels.





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Figure 1-1 SE2900 networking

A-SBC

Core network

Access networkMedia channel

Signaling channel

Fixed BB CS 3G PS LTE

NGN

IMS

(VoBB/RCS/VoLTE/Conference)

SoftX3000

CCF

Bill System ATS

CSCF

DNS

I-SBC

H.323 GW

Remote I-SBC

Carrier

network

AG Cable MGW GGSN PGW

MME

PCRF

VoLTE UEPOTS VoBB UE/RCS UE/SIP PON CS UE RCS UE/SIP UE

NMS

Management

plane

NMS Client NMS Server BOSS

Management

channel

From the perspective of IP bearer, the access and core networks, as well as the media and

signaling channels, are all used to connect SE2900s to other devices.

At present, the SE2900 can interconnect with routers and switches.

Figure 1-2 shows the networking in which the SE2900 interconnect with routers.

Figure 1-2 Interconnection between the SE2900 and routers

Router 1

Router 2

Access

Network/

Core

Network





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In this networking, the SE2900 is directly connected to routers through ports, and no

switching device exists between the SE2900 and routers. The SE2900 forwards traffic to

router 1 and router 2 using static routes.

Figure 1-3 shows the networking in which the SE2900 interconnect with switches.

Figure 1-3 Interconnection between the SE2900 and switches

LAN Switch 1

Access

Network/

Core

Network

LAN Switch 2

In this networking, the SE2900 is directly connected to switches through ports, and no device

exists between the SE2900 and switches. The SE2900 forwards traffic to LAN Switch 1 and

LAN Switch 2 using active/standby ports or static routes.

In the preceding networking modes, IP-related service features must be deployed to meet

carriers' requirements on interconnection compatibility and reliability. For details about the

features, see Chapter 2 "IP Networking Features."

Different features are used in different networking solutions. For details about how to use the

features in specific networking solutions, see Chapter 4 "Networking Solutions."

1.2 VRF Service Overview

Virtual routing and forwarding (VRF) is a technology used to establish multiple virtual routers

on a physical router on the IP network. Every VRF has its own routing table, IP address, and

interface. VRF can be used to separate IP addresses from routes on a VPN. VRF allows

multiple instances of a routing table to co-exist within the same router on the VPN.

VPN1

CESite1

VPN2

CESite2

Service provider's backbone

PE

PE

PE

VPN2

CE

CESite3

VPN1

Site4





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The preceding figure shows a typical BGP/MPLS IP VPN network. Site 1 and site 3 belong to

VPN1, and site 2 and site 4 belong to VPN2. As site 1 and site 2 belong to different VPNs, the

IP addresses used to connect the PE to site 1 and site 2 may be the same. To prevent address

overlap, VRF must be configured on the PE, so that the interfaces connecting the PE to site 1

and site 2 can be classified into different VRFs to separate IP addresses from routes.

VRF provides the network separation and address overlap functions to resolve the IPv4

address exhaustion issue. Using the VRF feature, the SE2900 can be connected to different

VPNs with the same IP address and supports the overlap of access-side addresses, the overlap

of core-side addresses, and the overlap of core and access network addresses.

Core network

Access network 1 Access

network 2

BRASBRAS

A-BAC

full proxy

10.0.1.1 to 10.0.1.255 10.0.1.1 to 10.0.1.255

Core network

Access network

BRAS

A-BAC

full proxy

Core network

172.1.1.1~172.1.1.255 172.1.1.1~172.1.1.255

Core network

Access network

BRAS

A-BAC

full proxy

10.0.1.1 to 10.0.1.255

10.0.1.1~10.0.1.255


Technical White Paper for IP 2 IP Networking Features



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2 IP Networking Features

2.1 Overview

2.2 Port

Ports on SE2900 service boards (SPUA0 and SPUA1) are classified into GE optical/electrical

ports and 10GE optical ports. The ports can work in full-duplex mode.

GE ports comply with 1000Base SFP standards. They can be configured as GE optical

ports by inserting GE optical modules, or as GE electrical ports by inserting electrical

port modules, depending on the network environment.

CAUTION

Electrical modules can be inserted into ports 0, 2, 4, and 6. For the ease of plug and unplug,

do not use ports 1, 3, 5, and 7 for electrical modules.

10GE optical ports comply with 10GBase SFP+ standards. A 10GE optical port can be

degraded to a GE optical interface by running MOD PORT.

− Positions of ports on the SPUA0/SPUA1

Ports on SE2900 XMUs are classified into 10M/100M/1000M auto-sensing Ethernet

electrical ports, Fabric-plane cascading ports, and Base-plane cascading ports.





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10M/100M/1000M auto-sensing Ethernet electrical ports comply with 1000Base-TX

physical layer specifications and are compatible with 10Base-T and 100Base-TX

physical layer specifications.

Fabric-plane cascading ports, which are QSFP+ ports, comply with 40GBASE-XR4

standards. MPO multimode optical fibers are used for the ports.

Base-plane cascading ports comply with 1000Base-TX physical layer specifications and

are compatible with 10Base-T and 100Base-TX physical layer specifications.

− Positions of ports on the MXUA0

2.3 Interface

SE2900 service boards use interfaces to exchange packets with other devices on the network.

All service packets are sent or received by interfaces. An interface carries various attributes,

such as the interface IPv4/IPv6 address, subnet mask, Address Resolution Protocol (ARP)

proxy, MTU, and network interface working mode. Interfaces are classified into main

interfaces and subinterfaces.

Main interface: You can configure a main interface on a physical interface by setting

attributes, such as the MTU and network interface working mode.

Subinterface: You can configure subinterfaces on a main interface to send or receive

VLAN packets. Every virtual local area network (VLAN) on a main interface must be

configured with subinterfaces.

Eth-trunk interface: Eth-trunk is an interface trunking technology which bundles multiple

Ethernet physical interfaces to a logical interface. The logical interface is an Eth-trunk

interface, (also called a load-balancing group or link aggregation group) and the bundled

physical interfaces are member interfaces.

2.4 Eth-trunk

An Eth-trunk interface has three operating modes:

Active/standby mode: On an Eth-trunk interface, only one member link is in the Up state,

and this link is called the primary link. All the other links are backup links. When the

primary link goes Down, traffic on this link is switched to other links automatically.

Load-balancing mode: On an Eth-trunk interface, each member link is in the Up state,

and traffic is load balanced among these links.

Static Link Aggregation Control Protocol (LACP) mode: On an Eth-trunk interface, M member links are primary links and N member links are backup links. When the primary





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links go Down, traffic on the links is switched to one backup link which is of top priority

among N backup links.

LACP provides a standard negotiation mechanism for a switching device. This ensures that the switching

device can automatically create and enable an aggregation link according to its configurations. After the

aggregation link is created, LACP is responsible for maintaining the link status. When the link aggregation

condition is changed, LACP automatically adjusts or disables the aggregation link.

The member interfaces of an Eth-trunk can be deployed on the active and standby SPUs that house the same

HRU module and cannot be deployed for different HRUs.

The Eth-trunk function is used to guarantee network reliability and increase interface

bandwidth at low cost.

The Eth-trunk interface in active/standby mode is applicable to the networks which have

high network reliability but low interface bandwidth requirements.

The Eth-trunk interface in load-balancing mode is applicable to the networks which have

high interface bandwidth requirements.

The Eth-trunk interface in static LACP mode is applicable to the networks which have

high network reliability and high interface bandwidth requirements. Trunk, as a link

aggregation technology, can increase the bandwidth by binding multiple physical

interfaces to a trunk interface. Nevertheless, the trunk technology is weak in fault

detection, and can detect only the link disconnection, but not other faults, such as the link

layer fault and link misconnection. The Link Aggregation Control Protocol (LACP) is

introduced as an alternative, which can improve the fault tolerance of the trunk, ensure

the high reliability of the member links.

2.4.1 Eth-trunk Interface in Active/standby Mode

Figure 2-1 shows the networking for an Eth-trunk interface in active/standby mode. Member

interfaces of the Eth-trunk interface connect to different routers and only one member

interface is in the active state. In active/standby mode, one Eth-trunk link is in the active state

and the other Eth-trunk link is in the standby state. When the active member interface is faulty,

traffic is switched to the standby member interface.

Figure 2-1 Networking for an Eth-trunk interface in active/standby mode

Router B Router A

SBC

Eth-trunk

Primary linkBackup link

The SE2900 can automatically detect the status of physical interfaces but cannot

automatically obtain the status of physical links. In the networking for an Eth-trunk interface

in active/standby mode, if the primary link is faulty but the active interface is normal in the

physical state, the SE2900 cannot detect this situation. Consequently, the SE2900 does not





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transmit the data to the peer device through the standby interface and backup link, causing

communication failures.

To avoid preceding communication failures, apply the Address Resolution Protocol (ARP)

probe function on the Eth-trunk interface in active/standby mode. An active/standby

switchover is performed on the Eth-trunk interface if the ARP probe function is enabled, the

physical status of the active interface is normal but the link is faulty, or the peer device is

detected faulty by the active interface.

2.4.2 Eth-trunk Interface in Load-balancing Mode

Figure 2-2 shows the networking for an Eth-trunk interface in load-balancing mode. Member

interfaces of the Eth-trunk interface connect to a router and operate in the active state. Traffic

is load balanced among member links according to configured weights. In this mode, all

Eth-trunk links are in the active state. When one physical interface is faulty, traffic is load

balanced among available physical interfaces.

Figure 2-2 Networking for Eth-trunk interfaces in load-balancing mode

Router B Router A

SBC

Eth-trunk 2 Eth-trunk 1

Primary linkBackup link

In an Eth-trunk interface in load-balancing mode, the number of member interfaces in the Up

state will have an impact on the status and bandwidth of the Eth-trunk interface. To minimize

the impact of member link changes on an Eth-trunk link, you need to set the minimum

number of active member links in the Eth-trunk link.

2.4.3 Eth-trunk Interface in Static LACP Mode

LACP, as specified in the IEEE 802.3ad, is the protocol to implement dynamic link

aggregation and de-aggregation. LACP enables information exchange between both ends

through Link Aggregation Control Protocol Data Units (LACPDUs). In static LACP mode,

after member interfaces are added into the trunk, each end sends LACPDUs to inform the

peer end of its system priority, MAC address, member interface priorities, interface numbers,

and keys. After being informed of the information, the peer end compares the

information with that saved on itself, and selects interfaces that can be aggregated. Then,

through the LACP negotiation, both ends agree on the active interfaces and active links.

As shown in Figure 2-3, you need to manually create an Eth-trunk in static LACP mode on

the SE2600 and Router A and add member interfaces to the Eth-trunk. Then the member

interfaces are enabled with LACP, and devices at both ends can send LACPDUs to each other.





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Figure 2-3 LACPDUs sent in static LACP mode

As shown in Figure 2-4, after devices at both ends select the Actor, both devices select active

interfaces according to the priorities of interfaces on the Actor. Then active interfaces are

selected, active links in the LAG are specified, and load balancing is implemented among

these active links.

Figure 2-4 Selecting active interfaces in static LACP mode

In static LACP mode, if a device at one end detects the following events, a link switchover is

triggered in the LAG if any of the following conditions is met.

An active link goes Down.

LACP discovers a link failure.

An active interface becomes unavailable.

When any of the preceding triggering conditions is met, the link switchover occurs in the

following order:

The faulty link is disabled.

The backup link of the highest priority is selected to replace the faulty active link.

The backup link of the highest priority becomes the active link and then forwards data.

2.5 IPv4 Address

SE2900 service boards support two types of IP addresses for packer sending, receiving, and

processing: interface IP addresses and service IP addresses.

An interface IP address is configured for a main interface or subinterface to directly

communicate with neighboring network devices instead of processing services.





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All the IP addresses involved in the communication between the SBC and other network

devices are called service IP addresses. Service IP addresses include but are not limited

to the access-side media address, access-side signaling address, core-side media address,

and core-side signaling address. Service IP addresses do not directly communicate with

neighboring network devices. Interfaces or interface IP addresses are used in routing or

ARP proxy mode to achieve the communication.

2.6 IPv6 Address

IPv6 is the second generation Internet protocol at the network layer. It is also termed as IP

next generation (IPng).It is a standard released by IETF as an IPv4 update. Significantly, IPv6

is different from IPv4 in that the address length is increased from 32 bits to 128bits.With its

simplified packet headers, sufficient address spaces, hierarchical address structure, flexible

extension headers, and enhanced neighbor discovery mechanism, IPv6 technologies will be

the appropriate substitute of the IPv4 technologies. Generally, IPv6 technologies properly

resolve the problem of IP address insufficiency, are compatible with existing network

applications, support smooth transition from IPv4, and interwork with IPv4 networks.

IPv6-related concepts are as follows:

1. IPv6 header format

Figure 2-5 Comparison between an IPv4 header and an IPv6 header

Version Traffic Class Flow Label

Payload Length Next Header Hop Limit

Source Address(128bits)

Destination Address(128bits)

Nextheader

Nextheader

Extension Header Data

Extension Header Data

0 3 11 317 15 23

Basic

header

Extension

headers

Version

0 3 11 317 15 23

IHL TOS Total length

Identification Flags

TTL Protocol Header Checksum

Source address(32bits)

18

Fragment Offset

Destination address(32bits)

Options

…

IPv4 header

IPv6 header

In the preceding figure, the IPv4 and IPv6 headers in the same color have the same function.

The following table lists the explanations to these headers:

IPv4 Header IPv6 Header Comparison

Version (4bit) Version (4bit) These two fields have the same function.

Each of these fields refers to the Internet

protocol version. For an IPv6 header, the

Version field is set to 6.





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IHL (4bit) - The IPv6 header does not carry this

field.

This 4-bit header indicates the header

length, covering the length of all option

fields. That is, the IPv4 header length is

not fixed. In IPv6 packets, extension

headers are used instead of option fields.

The total header length of a basic IPv6

header is 40 bits.

Type of service (8bit) Traffic class (8bit) These two fields have the same function.

The Traffic class field in an IPv6 header

is similar to the Type of Service field in

an IPv4 packet. This field uses DSCP to

mark IPv6 packets and indicate how the

IPv6 packets to be processed.

- Flow label (20bit) This field is only available in IPv6

packets and used to identify IPv6 data

streams.

However, no details on the management

and processing of the stream tags are

available in current standard. After this

field is set in IPv6 packets, devices that

receive the IPv6 packets categorize the

IPv6 packets into different streams

based on the value of this field and

process them accordingly. Due to this

field, QoS assurance can be

implemented on IPv6 packets that carry

IPSec payloads.

Total length (16bit) Payload length

(16bit)

These two fields have the same function.

These fields are used to indicate the

payload lengths in the IPv4 and IPv6

packet, respectively. A valid payload

refers to the datagram that follows the IP

headers. In IPv6 packets that carry

extension headers, the valid payload

follows the extension headers.

Identification (16bit) - This field is unavailable in IPv6 packets

because packet fragmentation is

different in IPv4 and IPv6.

In IPv4 packets, the flags field, offset

field, and this field are related to packet

fragmentation. This field is specified at

the source. If an IPv4 packet is

fragmented, each fragment carries this

field so that all fragments can be

assembled into the original packet after

they arrive at the destination.





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Flags (3bit) - This field is unavailable in IPv6 packets



In an IPv4 packet, this field is 3 bit long.

Only two bits are used: one bit is used to

identify whether this IPv4 packet can be

fragmented, and the other bit is used to

indicate whether the current segment is

the last one.

Fragment offset

(13bit)

- This field is unavailable in IPv6 packets



This field specifies the offset of a

particular fragment relative to the

beginning of the original IP packet.

Protocol (8bit) Next header (8bit) These two fields have the same function.

This field in an IPv6 packet indicates the

information types of the extension

headers that follow the basic IPv6

headers. The information types defined

for this field are the same as those

defined in the protocol field in IPv4

packets.

Header checksum

(16bit)

- Checksums are available at layer 2 and

layer 4, and therefore the checksum at

layer 3 is redundant. In IPv6, the header

checksum at layer 3 is subtracted.

TTL (8bit) Hop limit (8bit) These two fields have the same function.

In an IPv6 packet, this field specifies the

maximum number of hops that the IPv6

packet can pass, and is the same as the

TTL field in an IPv4 packet.

Source address

(32bit)

Source address

(128bit)

These fields indicate the source IP

address of an IPv4 packet and an IPv6

packet, respectively. In an IPv6 packet,

the source IP address is 128 bits long.

Destination address

(32bit)

Destination address

(128bit)

These fields indicate the destination IP

address of an IPv4 packet and an IPv6

packet, respectively. In an IPv6 packet,

the destination IP address is 128 bits

long.

Option (variable

length)

- In IPv6 packets, extension headers are

used instead of options, reducing the

overhead consumed during packet

transmission.





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2. IPv6 address format

A 128-bit IPv6 address can be represented in either of the following formats:

X:X:X:X:X:X:X:X

An IPv6 address is a series of hexadecimal numerals separated by colons (:).Specifically, each

IPv6 address contains eight 16-bit hexadecimal numerals, each of which is represented by

four hexadecimal digits. The following is an example IPv6 address:

2031:0000:130F:0000:0000:09C0:876A:130B

To simplify handwriting, the leading zeroes in each 16-bit block can be omitted. Therefore,

the preceding IPv6 address can be simplified as follows:

2031:0:130F:0:0:9C0:876A:130B

In addition, if two or more consecutive blocks are all zeroes, double colons (::) can be used to

further simplify the IPv6 representation. Therefore, the preceding IPv6 address can be further

simplified as follows:

2031:0:130F::9C0:876A:130B

In each IPv6 address, only one double-colon (::) can be used. If two or more double-colons are used, the

number of zeroes in each 16-bit block cannot be determined when the IPv6 address is restored to its

128-bit version.

X:X:X:X:X:X:d.d.d.d

In the preceding format, each X represents a high-order 16-bit block consisting of several

hexadecimal digits, and each d represents a low-order 8-bit block consisting of several

decimal digits. In fact, the four low-order 8-bit blocks constitute a standard IPv4 address.

Note that the SE2900 supports IPv6 addresses in the first format but not those in the second

format.

When configuring IP addresses on the SE2900, you can use any IPv6 addresses that

comply with RFC 4291 and RFC 5952.The IPv6 addresses output by the SE2900 are mainly

in the format defined in RFC 4291, and certain output IPv6 addresses are in the format

defined in RFC 5952.

3. IPv6 address structure

An IPv6 address consists of the following two parts:

Network prefix: The length of the network prefix is variable in bits. The network

prefixes in an IPv6 address and an IPv4 address are used to identify the network to which

the address belongs.

Interface identifier: The length of the interface identifier is the difference between 128

and the length of the network prefix. It is similar to the host ID in an IPv4 address.

Figure 2-6 shows the structure of the IPv6 address 2001:A304:6101:1::E0:F726:4E58 /64.

Figure 2-6 Structure of the IPv6 address 2001:A304:6101:1::E0:F726:4E58 /64

2001:A304:6101:0001 0000:00E0:F726:4E58

64 bits

Network prefix Interface identifier

64 bits





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SPUs on the SE2900 support two types of IPv6 addresses for packet sending, receiving, and

processing and they are interface IPv6 addresses and service IPv6 addresses.

2.7 IPv4/IPv6 Dual Stack

The SE2900 supports IPv4/IPv6 dual stack defined in RFC 4213.You can configure an IPv4

address and an IPv6 address on an interface and use the interface to access IPv4 and IPv6

networks.

2.8 IP Routing

Routing information is used to guide packet transmission. Routing is a process of selecting

routes for packets. On the SE2900, a routing table is saved on every VRF, and every routing

entry in the table specifies an SE2900 physical interface used to transmit a packet to a subnet

or host. The packet can then be sent to the next network device along the path or directly sent

to the destination host.

The following concepts are associated with IP routing:

1. Routing attributes

Destination address: It is used to identify the destination address or network of an IP

packet.

Network mask: Combined with the destination address, it is used to identify the

network segment on which the destination host or router resides.

Output interface: It indicates the interface from which an IP packet is forwarded.

Next-hop IP address: It specifies the IP address of the next network device to which

an IP packet is transmitted.

Priority: It is used to select the optimal route. A destination address may correspond

to different next hops. The route with the highest priority (smallest priority value) is

selected as the optimal route.

Route status: It specifies whether a route is active or not. If the routing status is

active, the route is available. If the routing status is inactive, the route is

unavailable.

2. Routing table

A routing table saves the routing information discovered by a routing protocol. On the

SE2900, a routing table is saved on every VRF. Every routing entry in the routing table

contains the destination address, subnet mask, discovery protocol, routing priority,

next-hop address, and egress information.

3. Routing principle

If multiple routes are destined for the same network address, routes are selected in

compliance with the following rules:

The route with the longest next-hop mask is preferred.

If the length of the next-hop mask is the same, the route with the higher priority is

preferred.





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The rule for selecting equal-cost routes is that signaling packets are distributed based on

the source and destination IP addresses and media packets are distributed based on the

stream ID.

4. Route classification

Direct route

After an IP address is configured for a router interface, the router generates a 32-bit

host route whose IP address is the same as the configured IP address and the

network route located in the same network segment as the configured IP address. A

direct route is discovered by a link-layer protocol.

For a host route, the IP address of the host is the destination address and the next-hop address is

127.0.0.1.

Static route

A static route is a special route that is manually configured by the network

administrator. On a network with a simple networking structure, correctly

configuring the static route can guarantee network security and network bandwidth.

Default route

A default route is a special static route that is used when the SE2900 cannot find

any matched routing entry. In a routing table, the default route is expressed as the

route to the network with the subnet mask 0.0.0.0. Using the default route can

reduce the routing time and bandwidth required for packet forwarding. The benefit

of using the default route is especially significant when the SE2900 processes

service traffic of a large number of subscribers.

2.9 VRF/VRF6

VRF is a technology that uses multiple routing instances to independently send and receive

packets to achieve network isolation and network address overlapping. Virtual routing

instances are independent of each other, with their respective routing entries, interfaces, and

IP addresses. Because the routing instances are independent, overlapping IP addresses or

subnet segments can be used in different VRF instances without conflicting with each other.

VRF is implemented on both the IPv4 and IPv6 protocol stack and VRF configurations on

both protocol stacks are independent from each other.

On a VRF network, the SBC groups networks into different VRF instances to access or isolate

networks with overlapping segments. Every VRF instance is logically considered as an

independent SBC. The objects in a VRF instance are as follows:

A group of interfaces that are bound to the same VRF instance: The interfaces include

both main interfaces and subinterfaces. An interface can belong to only one VRF

instance.

A group of IP addresses and subnets configured for the same interface: The IP addresses

and subnets configured for different VRF instances can overlap.

A group of independent service IP addresses: The service IP addresses of different VRF

instances can overlap.

An independent routing table in which the segments of different VRF instances can

overlap

A default VRF instance is created during system initialization of the SBC. The instance

includes a global route, all the unbound interfaces, and all the IP addresses for which no VRF





16

instance is specified. In addition, carriers can create multiple VRF instances that are

independent of each other.


Technical White Paper for IP 3 Networking Reliability



17

3 Networking Reliability

3.1 Active/Standby Processes

The SE2900 provides two boards, with one deployed with the active control-plane PCU and

forwarding-plane HRU and the other deployed with the standby control-plane PCU and

forwarding-plane HRU. This design prevents single point of failure from the process level to

the board level. The following figure shows the deployment of the active/standby PCUs and

HRUs.

OMU

PCU

HRU

PCU

HRU

Configuration channel

SPU SPU

Synchronization channel for data

forwarding

Backup channel for data

forwarding

Backup channel for data

forwarding

Configuration channel

Service packets

Control-plane PCU: is responsible for processing background data, interface

failure/restoration, and packets (such as ARP and BFD packets), adding, modifying, or

deleting data (such as ARP and routes) based on control packets, and synchronizing the

forwarding data to the forwarding process. The active and standby PCUs back up for each

other to forward data.

Forwarding-plane HRU: is responsible for receiving and sending IP packets and forwarding

packets at a high speed. The HRU receives the forwarding data synchronized from the PCU.

The active and standby HRUs back up for each other to forward data.

The active and standby PCUs and HRUs enhance reliability by:





18

Data forwarding on the HRU is not affected upon the switching between or the resetting

of the active and standby PCUs.

The call loss is within milliseconds upon HRU switching.

3.2 Active/Standby Ports

Active/standby ports are used on a Layer 2 network to improve system reliability. The

following figure shows the networking of the active/standby

ports.

Access

Network

10GE SFP+

1GE SFP

Slot 1 and slot 3, working as backup for each other, are connected to two LAN switches. If the

active port or the connection on the active port fails, services are switched from the active port

to the standby port. This solution has the following characteristics:

1. Services are not switched on the HRU when port switching occurs.

2. Port switching is performed within milliseconds (a minimum of 200 milliseconds).

This design brings a small call loss upon a single point of failure on a port, achieving high

service reliability.

3.3 Load Balancing

The SE2900 supports load balancing that allows multiple routes with the same destination

address and priority. If these routes are matched, all of them are adopted. Signaling packets

are forwarded to the destination address based on the source and destination IP addresses and

media packets are forwarded to the destination address based on the stream ID, achieving load

balancing.





19

3.4 Active/Standby Routes

The SE2900 supports active and standby routes to improve network reliability. Users can

configure multiple routes destined for the same destination as required. The route with the

highest priority serves as the active route, and the routes with lower priorities serve as the

standby routes.

Normally, the SE2900 adopts the active route to forward data. When a fault occurs on the line,

the active route becomes inactive and the SE2900 selects the route with the highest priority

among the standby routes to forward data. In this manner, the switching between the active

and standby routes is performed. If the active route restores, the route with the highest priority

changes from the inactive state to the active state and the SE2900 re-selects a route. As the

active route is with the highest priority, the SE2900 selects the active route to forward data. In

this manner, the switching from the standby route to the active route is achieved.

3.5 ARP Probe

The SE2900 can perform self-checks on the port status but fail to automatically obtain the

link-layer status. If the physical status of a port is normal but the link becomes faulty, data

cannot be sent to the peer device; as a result, the communication is interrupted. To prevent this

issue, users can enable APR probe in the active/standby or VRRP networking to enhance

network reliability.

The ARP probe function is used to send ARP requests to the peer device within a specified

period. The ARP response from the peer device is used to determine the network link status. If

the number of times the system fails to receive a response within the specified period reaches

the threshold or the failure rate within the specified period reaches the threshold, the ARP

probe is considered failed, the network link fails, and a probe failure alarm is generated. The

SE2900 participates in port switching arbitrary and triggers port switching. ARP probe can be

classified into gateway probe and active/standby probe based on the peer path detected by the

standby port.

In gateway probe mode, the active and standby ports on the SE2900 regularly use the IP

addresses configured on the ports to send ARP requests for the MAC addresses of

gateway addresses. An IP address must be configured on the standby port to implement

the probe.

In active/standby probe mode, the active port of the SE2900 regularly uses the

configured address to send the ARP request for the MAC address associated with the

gateway address. The standby port regularly uses IP address 0.0.0.0 to send the ARP

request for the MAC address associated with the active port address. In comparison with

the gateway probe mode, the active/standby probe mode uses less interface IP addresses

and therefore is recommended.

3.6 IPv6 Neighbor Discovery

IPv6 neighbor discovery (ND) is a technology that enables the SE2900 to check the status of

network connections based on the response to the Neighbor Solicitation message initiated by

the SE2900.If the SE2900 does not receive any response after initiating the maximum number

of consecutive Neighbor Solicitation messages or the percentage of Neighbor Solicitation

messages that are not responded within a period reaches the upper limit, the ND process fails.

In this case, an alarm indicating the failure is generated and the interface switchover is





20

implemented. Based on how IPv6 ND is implemented for the standby interface, IPv6 ND can

be implemented as follows:

1. In the gateway mode, the SE2900 sends Neighbor Solicitation messages through both the

active and standby interfaces to request the MAC address of the gateway. In this mode,

the standby interface must be configured with an independent IPv6 address.

2. In the active/standby mode, the SE2900 sends Neighbor Solicitation messages through

the active interface to request the MAC address of the gateway and sends Neighbor

Solicitation messages through the standby interface to request the MAC address of the

active interface. In this mode, the IP address of the standby interface is an all-zero IPv6

address. On live networks, this mode is recommended.

3.7 BFD

Bidirectional forwarding detection (BFD) provides a simple method of detecting the stream

transmission capability for a link or system, aiming at improving the link fault detection and

restoration efficiency.

BFD provides light-load and short-period detection for the faults on the channel between

neighboring forwarding engines. The channel faults can be about the interface, data link, or

even the forwarding engine. BFD can be used to rapidly detect faults about the

communication between neighboring devices so that the devices can quickly locate the fault

and switch traffic to the backup link, which speeds up network convergence and ensures

normal service operation. The mechanism reduces the impacts of device or link faults on

services and improves network usability. After the BFD-enabled device establishes peer

relationships with neighboring systems, every system monitors BFD probe packets sent from

other systems at the negotiated rate. The monitoring period can be specified at the millisecond

level.

On the SE2900, BFD can be performed in asynchronous mode or query mode. The difference

between the synchronization and query modes lies in the detection location. In

synchronization mode, the local end sends BFD control packets within a specified period, and

the remote end checks the transmitted BFD control packets. In query mode, the local end

checks the transmitted BFD control packets. Details are as follows:

Asynchronous mode

In this mode, BFD control packets are transmitted between systems within a specified

period. If the SE2900 does not receive the BFD control packets sent from the peer

system within the period, the session is considered Down.

Query mode

In this mode, every system is assumed to use an independent method of confirming the

connections to other systems. Once a BFD session is established, the system stops

sending BFD control packets. The system continues with sending periodic BFD control

packets until the connectivity needs to be verified. If the SE2900 does not receive any

response to the BFD control packets within the detection period, the session is

considered Down. If the SE2900 receives a response to the BFD control packets, no BFD

control packet is transmitted. The SE2900 does not support the query mode when it

functions as the local end but supports a reply to the query packets sent from the peer

system.

When BFD is bound to a static route and the static route changes from the active state to

inactive state upon a fault, traffic switches from the static route to a load-balancing or standby

route. If BFD detects that a fault is rectified, the static route changes from the inactive state to

the active state, and the route re-transmits traffic.





21

The SE2900 supports both BFD for IPv4 and BFD for IPv6.


Technical White Paper for IP 4 Networking Solutions



22

4 Networking Solutions

4.1 Overview

The SE2900 can interconnect with Layer 2 (LAN Switch) and Layer 3 (router)

devices. Different interconnection solutions are used based on the conditions of carriers'

networks. At present, the common networking solutions are Layer 2 active/standby

networking, dual-plane load balancing networking, VRRP networking, and VRF

networking with address overlapping. Table 4-1 lists the solutions.

Table 4-1 Networking solutions

Networking Solution

Interconnected Device

Description Remarks

Dual-plane load

balancing

networking

Dual-plane router The SE2900 is connected to a

dual-plane load-balancing router,

such as a PE, in direct or side

connection mode. Packets are

forwarded to the two planes in

load-balancing mode.

Active/standby

networking

Dual-plane switch The SE2900 is connected to switches

in direct or side connection mode.

Packets are forwarded to the master

switch in active/standby port mode.

Interconnection

with

VRRP-enabled

routers

VRRP-enabled

router

On an existing VRRP network, the

SE2900 is interconnected with

VRRP-enabled routers in

active/standby port mode.

VRF networking Different

networks with

overlapping

address segments

The SE2900 groups networks into

different VRF instances to access two

or more networks with overlapping

address segments.





23

4.2 Port Classification

4.2.1 Port Overview

The SE2900 supports two types of boards: MXU and SPU. The MXU provides functions

including device management, alarm management, and service configuration. The SPU

provides functions including access control, security, QoS, media transcoding, media firewall,

media/signaling proxy, NAT traversal, firewall traversal, flexible routing, network redundancy,

and encrypted transmission for signaling/media.

4.2.2 MXUA0 Ports

Figure 4-1 shows ports on the MXUA0. Table 4-2 lists the specifications of the ports.

Figure 4-1 Ports on the MXUA0

Table 4-2 Specifications of ports on the MXUA0

Board Name

Port Name Function Description Port Quantity

MXUA0 LAN port O&M network

port

The port mode is

10/100/1000M Base-T

auto-negotiation. The port type

is RJ-45. The cable type is

CAT5E. The port has two

indicators.

2

RS232

network port

Serial port for

system

commissioning

The port type is RJ-45. The

cable type is DB9-RJ45. The

standard RS232 network port

provides channels for program

loading, communication,

commissioning, and

monitoring.

1

RS485

network port

Serial port for

power

distribution

monitoring

The port type is RJ-45. The

cable type is DB9-RJ45. The

standard RS485 network port

monitors the PDB status.

1

Fabric port Fabric-plane

cascading port

The port mode is 40G

BASE-XR4 The port type is

QSFP+. The cable type is

2





24

Board Name


MPO. Fabric ports are used to

implement Fabric cascading

between the active and standby

subracks.

Base port Base-plane

cascading port

The port mode is

10/100/1000M Base-T

auto-negotiation. The port type

is RJ-45. The cable type is

twisted pair. Base ports are

used to implement Base

cascading between the active

and standby subracks.

2

4.2.3 SPUA0/SPUA1 Ports

Figure 4-2 shows ports on the SPUA0/SPUA1. Table 4-3 lists the specifications of the ports.

Figure 4-2 Ports on the SPUA0/SPUA1

Table 4-3 Specifications of ports on the SPUA0/SPUA1

Board Name


SPUA0/S

PUA1

SFP port 1GE

signaling/mana

gement port

The port type is LC jumpering

square optical fiber connector.

The cable type is optical fiber.

SFP ports are used for

signaling and management.

4

SFP+ port 10GE

signaling/medi

a port

The port type is LC jumpering

square optical fiber connector.

The cable type is optical fiber.

SFP+ ports are used for

signaling/media transmission.

4





25

4.2.4 Service-based Port Allocation

Both the SPUA0 and SPUA1 are equipped with 4*1GE and 4*10GE ports. Figure 4-3 shows

the service functions of different ports on an SPU.

In this section, ports are expressed in the format of GE Subrack ID-Slot ID-Interface number.

For example, port 2 in slot 1 subrack 0 is expressed as GE0-1-2. If only one SE2900 is

deployed, the default subrack ID is 0.

Figure 4-3 Port allocation on the SPU

Reserved port4

10GE SFP+

1GE SFP

01

02

03

04

05

06

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

Access-side signaling port

Access-side media port

Core-side signaling port

Core-side media port

Reserved

Access-side signaling/media port (small user

capacity)

Core-side media port (small user capacity)7

6

5

2 3

0 1

4

0

The rules for port allocation are as follows:

GE0-1-0 and GE0-4-0 are used to access access-side signaling traffic and some media

traffic.

GE0-1-4 and GE0-4-4 are used to access core-side signaling traffic. Port 4 in slots 3 and

6 does not need to access core-side signaling traffic and therefore is reserved.

Ports 0 and 1 in all slots are used to access access-side media traffic. The current service

traffic requires only one port, that is, port 0.

Ports 2 and 3 in all slots are used to access core-side media traffic. The current service


A 10GE optical port can be degraded to a GE optical port if the media traffic rate on the

ISU is less than or equal to1.6 Gbit/s and that on the ESU is less than or equal to 2.4

Gbit/s. Ports 5 and 7 can be added to access access-side media traffic and core-side

media traffic respectively as the service traffic increases.

GE electrical ports are used if the access-side media traffic is less than or equal to 0.8

Gbit/s. In this case, only ports 0, 2, 4, and 6 are available.

Ports in slots 1 and 4, as well as ports in slots 3 and 6, work in active/standby or


Every board must be allocated with access-side and core-side media ports. All

access-side or core-side ports must be connected to the same network.





26

In the case of multi-subrack cascading, every board in a subrack must be allocated with

access-side and core-side media ports. Access-side and core-side signaling ports reside

only in subrack 0, as shown in Figure 4-4.

Figure 4-4 Port allocation in other subracks

10GE SFP+

1GE SFP

01

02

03

04

05

06

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6



Lawful interception port


capacity)


6

5

2 3

0 1

Subrack 1

Reserved port4

4.3 Dual-plane Load Balancing Networking

4.3.1 Networking Scenario

The SE2900 is directly connected to routers.

The routers are deployed on a dual-plane network where both planes can forward service

packets.





27

4.3.2 Access-side Networking

Figure 4-5 Access-side networking where dual-plane load balancing is implemented

10GE SFP+

1GE SFP

Access

Network

Router 1 Router 2

Access-side signaling

and media

Access-side media

As shown in Figure 4-5, two routers are deployed in load-balancing mode on the access-side

network where both planes can forward service packets. In this situation, use the specified

traffic model to calculate the number of required cables on each board based on the traffic

volume and distribution. The product of the port quantity and port bandwidth must be no less

than the service bandwidth required by the specified board.

If a base board supports a maximum number of 40,000 concurrent audio sessions, the codec type is

G.711, the packetization time is 20 ms, and the Ethernet bandwidth required by a session flow is 95.2

kbit/s, the bandwidth required is 40000 x 95.2 kbit/s = 3.808 Gbit/s. In this case, only one 10GE port

needs to be configured on the board to access access-side media traffic. These specifications can also be

used to calculate the high bandwidth required by video traffic.

In this document, the bandwidth required when the number of accessed UEs reaches the upper

limit is used as an example for the scenarios where bandwidth requirements are not specified.

On the live network, the bandwidth required depends on the actual service traffic.

Pay attention to the following items for networking:

Services in slots 1 and 4, as well as services in slots 3 and 6, back up each other.

No real active/standby relationship exists between SE2900 service boards. Inside the SE2900, processes

that back up each other are deployed on different boards. In the case of a service failure, processes are

switched as the minimum switching objects. Ports on service boards are managed by HRU processes for

sending and receiving packets, and the active and standby HRU processes are deployed on adjacent

boards. Therefore, the boards work in active/standby mode in IP forwarding.


traffic. The two ports belong to different network segments.

Every pair of boards has its own media service addresses. GE0-1-0 and GE0-4-0 on the

two boards are used to implement load balancing. Media traffic is evenly distributed on

the two ports in route load-balancing mode, as shown in Figure 4-6.





28

Figure 4-6 Traffic sending to the access network

10GE SFP+

1GE SFP

On the routers interconnected with the SE2900, load balancing needs to be performed for

the traffic sent to the media service addresses.

Figure 4-7 Traffic receiving from the access network

10GE SFP+

1GE SFP

Access

Network

Router 1 Router 2

½ traffic ½ traffic

½ traffic





29

4.3.3 Core-side Networking

Figure 4-8 Core-side networking where dual-plane load balancing is implemented

10GE SFP+

1GE SFP

Core Network

Router 1 Router 2

Core-side signaling

Core-side media

Core-side networking is similar to access-side networking. The difference is that, in core-side

networking, signaling and media traffic must be separately processed. Therefore, in core-side

networking, an additional GE interface must be assigned for slot 1 and slot 4 in chassis 0 to

transmit separate signaling traffic. Generally, the assigned ports are GE0-1-4 and GE0-4-4.

Media and signaling traffic is balanced using the same load-balancing mode as that in

access-side networking.

4.3.4 Data Planning

Port Planning

The number of required access-side and core-side ports can be directly calculated using the

configurator and network design tool. You can then allocate ports based on allocation rules.





30

Reserved port 4

10GE SFP+

1GE SFP

01

02

03

04

05

06

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6





Reserved


capacity)


6

5

2 3

0 1

4

0

GE0-1-0 is used to access access-side signaling traffic and some media traffic.

GE0-1-4 is used to access core-side signaling traffic.













Table 4-4 lists the ports allocated to the SE2900 when the number of accessed UEs reaches

the upper limit.

Table 4-4 Port allocation when the number of accessed UEs reaches the upper limit

Traffic Type Port Allocated Remarks

Access-side signaling GE0-1-0 Access-side signaling traffic shares the

same port with access-side media traffic.

GE0-4-0 GE0-1-0 and GE0-4-0 back up each other in


Access-side media GE0-1-0 Each board supports a maximum of 16

Gbit/s traffic. GE0-4-0

GE0-3-0

GE0-6-0





31

Traffic Type Port Allocated Remarks

Core-side signaling GE0-1-4

GE0-4-4

Core-side media GE0-1-2

GE0-4-2

GE0-3-2

GE0-6-2

Address Planning

This section assumes that the access-network address segment is 10.0.0.0/8, the core-network

media address segment is 192.168.0.0/16, and the core-network signaling address segment is

192.168.2.0/24. Table 4-5 and Table 4-6 list examples for the service addresses and port

addresses to be planned.

Table 4-5 Service addresses to be planned

Network Address Remarks

Access-side

signaling address

10.1.1.1 This address is used to access UE registration and call

services. It must be bound to the HRU process in slot 1.

Access-side

media address

10.1.1.2 Every active board requires at least one access-side

media address. Every 20,000 concurrent sessions must

be allocated with one access-side media address. 10.1.1.3

Core-side

signaling address

192.168.1.1 This address must be bound to the HRU process in slot

1. Every 40,000 UEs must be allocated with one

core-side signaling address.

Core-side media

address

192.168.1.2 Every active board requires at least one core-side media

address. Every 20,000 concurrent sessions must be

allocated with one core-side media address. 192.168.1.3

A base SPUA0 supports 20,000 concurrent calls. The number of supported concurrent calls is increased

by 30,000 every time an expansion SPUA0 is added. Media IP addresses cannot be shared among

different boards. Therefore, the number of IP addresses on every board must be calculated. A pair of

media addresses, including an access-side media address and a core-side IP address, is required for every

20,000 concurrent calls. The number of required media addresses on a board equals to the maximum

number of the concurrent calls that the board supports divided by 20,000. Plan core-side and access-side

media addresses based on the number of accessed users. Every base SPUA0 uses a pair of media IP

addresses. Every expansion SPUA0 uses two pairs of media IP addresses.





32

A base SPUA1 supports 40,000 concurrent calls. The number of supported concurrent calls is increased

by 60,000 every time an expansion SPUA1 is added. Media IP addresses cannot be shared among

different boards. Therefore, the number of IP addresses on every board must be calculated. A pair of

media addresses, including an access-side media address and a core-side media address, is required for

every 20,000 concurrent calls. The number of required media addresses on a board equals to the

maximum number of concurrent calls that the board supports divided by 20,000. Plan access-side and

core-side media addresses based on the number of accessed users. Every base SPUA1 requires two pairs

of media IP addresses. Every expansion SPUA1 requires three pairs of media IP addresses.

Table 4-6 Interface addresses to be planned

Traffic Type Port Allocated Interface Address Mask Peer Address

Access-side

signaling

GE0-1-0 10.1.1.5 30 10.1.1.6

GE0-4-0 10.1.1.9 30 10.1.1.10

Access-side

media

GE0-1-0 10.1.1.5 30 10.1.1.6

GE0-4-0 10.1.1.9 30 10.1.1.10

GE0-3-0 10.1.1.13 30 10.1.1.14

GE0-6-0 10.1.1.17 30 10.1.1.18

Core-side

signaling

GE0-1-4 192.168.1.5 30 192.168.1.6

GE0-4-4 192.168.1.9 30 192.168.1.10

Core-side media GE0-1-2 192.168.1.13 30 192.168.1.14

GE0-4-2 192.168.1.17 30 192.168.1.18

GE0-3-2 192.168.1.21 30 192.168.1.22

GE0-6-2 192.168.1.25 30 192.168.1.26

Figure 4-9 Access-side interface address allocation

10GE SFP+

1GE SFP

Access

Network

Router 1 Router 2

GE0-3-0 10.1.1.13/30

GE0-6-0 10.1.1.17/30

GE0-1-0 10.1.1.5/30

GE0-4-0 10.1.1.9/30

Access-side signaling and media

Access-side media





33

Figure 4-10 Core-side interface address allocation

10GE SFP+

1GE SFP

Core Network

Router 1 Router 2

GE0-3-2 192.168.1.21/30

GE0-6-2 192.168.1.25/30

GE0-1-4 192.168.1.5/30

GE0-1-2 192.168.1.13/30

GE0-4-2 192.168.1.17/30

GE0-4-4 192.168.1.9/30

Core-side signaling

Core-side media

Every port requires an address that is on the same network segment as the interconnected

device. It is recommended that the addresses to be allocated be on the minimum network

segments with the mask length of 30. The number of required addresses depends on the user

capacity, as described in Table 4-7.

Table 4-7 Number of required addresses

User Capacity

Service Address Quantity

Interface Address Quantity

Remarks

≤ 250,000

(one pair of

the SPUA0s)

Access-side

signaling address x 1

Access-side media

address x 1

Core-side signaling

address x 7

Core-side media

address x 1

Access-side address x 2

Core-side signaling

address x 2

Core-side media

address x 2

The access-side or

core-side traffic per

board is less than or

equal to 8 Gbit/s.

Every 40,000 UEs

must be allocated with

one core-side signaling

address.

Every 20,000 sessions


one access-side media

address and one

core-side media

address.

≤ 500,000

(one pair of

the SPUA1s)

Access-side


Access-side media

address x 2

Core-side signaling

address x 13


Core-side signaling

address x 2

Core-side media

address x 2

The access-side or



equal to 8 Gbit/s.





34

User Capacity



Remarks

Core-side media

address x 2

≤ 1,200,000

(two pairs of

the SPUA1s)

Access-side


Access-side media

address x 5

Core-side signaling

address x 30

Core-side media

address x 5


Core-side signaling

address x 2

Core-side media

address x 4

The access-side or



equal to 8 Gbit/s.

≤ 2,600,000 Access-side


Access-side media

address x 11

Core-side signaling

address x 65

Core-side media

address x 11


Core-side signaling

address x 2

Core-side media

address x 8

Dual-subrack

cascading



Access-side media

address x 17

Core-side signaling

address x 100

Core-side media

address x 17

Access-side address x

12

Core-side signaling

address x 2

Core-side media

address x 12

Three-subrack

cascading

Local Route Planning

Every board is directly connected to the access and core networks. Therefore, route

configuration is simple and you only need to add an equivalent route to every port. Table 4-8

lists the specific routing entries.

Table 4-8 Routing entries

Address Type

Destination Network Segment

Mask Gateway Address Priority

Access-side

address

10.0.0.0 255.0.0.0 10.1.1.6 60

10.0.0.0 255.0.0.0 10.1.1.10 60

10.0.0.0 255.0.0.0 10.1.1.14 60

10.0.0.0 255.0.0.0 10.1.1.18 60





35

Address Type


Mask Gateway Address Priority

Core-side

signaling

address

192.168.2.0 255.255.255.0 192.168.1.6 60

192.168.2.0 255.255.255.0 192.168.1.10 60

Core-side

media address

192.168.0.0 255.255.0.0 192.168.1.14 60

192.168.0.0 255.255.0.0 192.168.1.18 60

192.168.0.0 255.255.0.0 192.168.1.22 60

192.168.0.0 255.255.0.0 192.168.1.26 60

Remote Route Planning

On the routers interconnected with the SE2900, configure routes that are destined for SE2900

service addresses and have the same priority.

Table 4-9 Static route configuration on router 1

Address Type Destination Network Segment

Mask Gateway Address

Priority

Access-side

signaling address

10.1.1.1 255.255.255.255 10.1.1.5 60

Access-side media

address

10.1.1.2 255.255.255.255 10.1.1.5 60

10.1.1.3 255.255.255.255 10.1.1.13 60

Core-side signaling

address

192.168.1.1 255.255.255.255 192.168.1.5 60

Core-side media

address

192.168.1.2 255.255.255.255 192.168.1.13 60

192.168.1.2 255.255.255.255 192.168.1.21 60

Table 4-10 Static route configuration on router 2



Priority

Access-side

signaling address

10.1.1.1 255.255.255.255 10.1.1.9 60

Access-side

media address

10.1.1.2 255.255.255.255 10.1.1.9 60

10.1.1.3 255.255.255.255 10.1.1.17 60

Core-side

signaling address

192.168.1.1 255.255.255.255 192.168.1.9 60





36



Priority

Core-side media

address

192.168.1.2 255.255.255.255 192.168.1.17 60

192.168.1.2 255.255.255.255 192.168.1.25 60

4.3.5 Reliability

If the SE2900 is connected to a dual-plane network where routers are deployed in

load-balancing mode, BFD must be configured for every physical link to ensure the reliability

of the associated static route. Table 4-11 lists the BFD sessions to be configured.

Table 4-11 BFD sessions to be configured

Port Local IP Address Peer IP Address Remarks

GE0-1-0 10.1.1.5 10.1.1.6 BFD needs to be enabled

for every physical link.

GE0-4-0 10.1.1.9 10.1.1.10

GE0-3-0 10.1.1.13 10.1.1.14

GE0-6-0 10.1.1.17 10.1.1.18

GE0-1-4 192.168.1.5 192.168.1.6

GE0-4-4 192.168.1.9 192.168.1.10

GE0-1-2 192.168.1.13 192.168.1.14

GE0-4-2 192.168.1.17 192.168.1.18

GE0-3-2 192.168.1.21 192.168.1.22

GE0-6-2 192.168.1.25 192.168.1.26

4.4 Dual-plane Load Balancing Networking Using Eth-Trunk Interfaces


1. The SE2900 is directly connected to routers.

2. The router uses the LAG function to implement port convergence for the SE2900.

3. The routers are deployed on a dual-plane network where both planes can forward service

packets.





37


Figure 4-11 Access-side networking where dual-plane load balancing using Eth-trunk interfaces is

implemented

10GE SFP+

1GE SFP

Access

Network

Router 1 Router 2

Access-side

signaling/media

Eth-

trunkA1

Eth-

trunkA2

10GE SFP+

1GE SFP

Access

Network

Router 1 Router 2

Access-side

media

Eth-

trunkA3

Eth-

trunkA4

As shown in the preceding figures, no 10GE port is available on the access network.

Therefore, the 10GE optical interfaces available on the SE2900 must be degraded to GE optical interfaces. In this case, three ports on each board at the access side must be used to





38

ensure that all service traffic can be processed. To simplify the configuration, Eth-trunk

interfaces are recommended for the connection between the SE2900 and routers/switches. The

connected routers must be deployed in load-balancing mode on the access network where

both planes forward service packets. Each router supports the Eth-trunk function. In this case,

use the specified traffic model to calculate the number of required cables on each board based

on the traffic volume and distribution. Note that 80% of the product of the port quantity and

port bandwidth must be no less than the service bandwidth required by the specified board.

If a base board supports a maximum number of 20000 concurrent audio sessions, the codec type is G.711,

the packetization time is 20 ms, and the Ethernet bandwidth required by a session flow is 95.2 kbit/s, the

bandwidth required is 20000 x 95.2 kbit/s = 1.904 Gbit/s. In this case, only three GE ports need to be

configured on the board to access access-side media traffic. These specifications can also be used to

calculate the high bandwidth required by video traffic.




This networking solution consists of the following items:

1. Services in slots 1 and 4 back up each other. Services in slots 3 and 6 back up each other.






2. Ports GE0-1-0, GE0-1-1, and GE0-1-5 in slot 1 are bundled into an Eth-trunk interface.

Ports GE-4-0, GE0-4-1, and GE0-4-5 in slot 4 are bundled into another Eth-trunk

interface. Both Eth-trunk interfaces belong to separate network segments and are used to

access access-side signaling traffic. In addition, these Eth-trunk interfaces are used to

access media traffic of no greater than 1.6 Gbit/s. If a separate Rf or Rx interface is

required, ports GE0-1-5 and GE0-4-5 are unavailable. In this case, the media traffic must

be no greater than 0.8 Gbit/s.

3. Ports GE0-3-0, GE0-0-1, and GE0-3-5 are bundled into an Eth-trunk interface. Ports

GE0-6-0, GE0-6-1, and GE0-6-5 are bundled into another Eth-trunk interface. Both

Eth-trunk interfaces reside in separate network segments and access access-side media

traffic of no greater than 2.4 Gbit/s

4. Each pair of boards is configured with a media address. Media traffic is evenly distributed

among all ports of this pair of boards using the load-balancing routes and Eth-trunk

function. Figure 4-12 shows the detail.





39


10GE SFP+

1GE SFP

1/2 traffic 1/2 traffic


5. On the routers interconnected with the SE2900, load balancing needs to be performed for



10GE SFP+

1GE SFP

Access

Network

Router 1 Router 2

1/2 traffic



1/2 traffic





40


Figure 4-14 Core-side networking where dual-plane load balancing using Eth-trunk interfaces is

implemented

10GE SFP+

1GE SFP

Core Network

Router 1 Router 2

Core-side signaling

Core-side media

Eth-

trunkC1

Eth-

trunkC2

10GE SFP+

1GE SFP

Core Network

Router 1 Router 2

Core-side media

Eth-

trunkC3

Eth-

trunkC4


networking, signaling and media traffic must be separately processed. Therefore, additional





41

GE ports in slots 1 and 4 of subrack 0, which are GE0-1-4 and GE0-4-4, are required in

core-side networking to transmit signaling traffic. Eth-trunk is not required for these GE ports.


access-side networking. If a separate Rf or Rx interface is required, ports GE0-1-7 and

GE0-4-7 are unavailable. In this case, the media traffic must be no greater than 1.6 Gbit/s.

4.4.4 Data Planning

1. Port Planning

The number of required access-side and core-side ports can be directly calculated using

the configurator and network design tool. You can then allocate ports based on allocation

rules.

10GE SFP+

1GE SFP

01

02

03

04

05

06

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

ESU:

Access-side signaling/media

Core-side media

Reserved

Core-side media (GE) / Rf7

5

6

2 3

0 1

Core-side signaling4

ISU:

Access-side media (GE) / Rx

Access-side media

Core-side media

Reserved

Core-side media (GE)7

5

6

2 3

0 1

Reserved4

Access-side media (GE)

1. GE0-1-0 and GE0-4-0 are used to access access-side signaling traffic and some

media traffic.

2. GE0-1-4 and GE0-4-4 are used to access core-side signaling traffic. GE0-3-4 and

GE0-6-4 does not need to access core-side signaling traffic and therefore is

reserved.

3. Ports 0 and 1 in all slots are used to access access-side media traffic.

4. Ports 2 and 3 in all slots are used to access core-side media traffic.

5. A 10GE optical port can be degraded to a GE optical port if the media traffic rate on

the ISU is less than or equal to1.6 Gbit/s and that on the ESU is less than or equal to

2.4 Gbit/s. Ports 5 and 7 can be added to access access-side media traffic and

core-side media traffic respectively as the service traffic increases.

6. GE electrical ports are used if the access-side media traffic is less than or equal to

0.8 Gbit/s. In this case, only ports 0, 2, 4, and 6 are available.

7. Ports in slots 1 and 4, as well as ports in slots 3 and 6, work in active/standby or


Once the 10GE ports are degraded to GE ports, port planning for a fully configured

SE2900 is as follows:





42

Network Port Allocated Remarks

Access-side

signaling and media

GE0-1-0 These ports are bundled into an

Eth-trunk interface named

Eth-trunkA1 This Eth-trunk

interface can access signaling


and media traffic of no greater than

1.6 Gbit/s.

GE0-1-1

GE0-1-5



Eth-trunkA2, which works in

load-balancing mode with

Eth-trunkA1.

GE0-4-1

GE0-4-5

Access-side media GE0-3-0 These ports are bundled into an



interface can access media traffic

of no more than 2.4 Gbit/s.

GE0-3-1

GE0-3-5



Eth-trunkA4, which works in


Eth-trunkA3.

GE0-5-1

GE0-5-5

Core-side signaling GE0-1-4 These ports works in

load-balancing or active/standby

mode. Eth-trunk is not required. GE0-4-4

Core-side media GE0-1-2 These ports are bundled into an


Eth-trunkC1. This Eth-trunk



GE0-1-3

GE0-1-7



Eth-trunkC2, which works in


Eth-trunkC1.

GE0-4-3

GE0-4-7






GE0-3-3

GE0-3-7



Eth-trunkC4, which works in


Eth-trunkC3.

GE0-5-3

GE0-5-7





43

2. Address Planning

This section assumes that the access-network address segment is 10.0.0.0/8, the

core-network media address segment is 192.168.0.0/16, and the core-network signaling

address segment is 192.168.2.0/24. The following table lists examples for the service

addresses and interface addresses to be planned.

1. Service addresses to be planned


Access-side

signaling address

10.1.1.1 This address is used to access UE registration

and call services. It must be bound to the HRU

process in slot 1.

Access-side

media address

10.1.1.2 Every active board requires at least one

access-side media address. Every 20,000

concurrent sessions must be allocated with one

access-side media address.

10.1.1.3

Core-side

signaling address

192.168.1.1 This address must be bound to the HRU

process in slot 1. Every 40,000 UEs must be

allocated with one core-side signaling address.

Core-side media

address


core-side media address. Every 20,000


core-side media address.

192.168.1.3

Each SPUA0 that serves as the ISU supports a maximum of 20,000 concurrent calls. Each SPUA0 that is

added as an ESU increases the maximum number of concurrent calls by 30,000. Media addresses cannot

be shared across SPUs. Therefore, the number of IP addresses required on each SPU must be calculated.

One pair of media addresses, including an access-side media address and a core-side IP address, is

required for every 20,000 concurrent calls. The number of required media addresses on a board merely

equals to the maximum number of concurrent calls that the board supports divided by 20,000. Plan

access-side and core-side media addresses based on the number of accessed users. That is, each SPUA0

that serves as the ISU requires a pair of media addresses, and each SPUA0 that serves as the ESU

requires two pairs of media addresses.








that serves as the ISU requires two pairs of media addresses, and each SPUA1 that serves as the ESU

requires three pairs of media addresses.

2. Interface addresses to be planned





44

Network Interface Allocated

Interface Address

Mask Peer Address

Access-side

signaling and

media

Eth-TrunkA1 10.1.1.5 30 10.1.1.6

Eth-TrunkA2 10.1.1.9 30 10.1.1.10

Eth-TrunkA3 10.1.1.13 30 10.1.1.14

Eth-TrunkA4 10.1.1.17 30 10.1.1.18

Core-side

signaling

GE0-1-4 192.168.1.5 30 192.168.1.6

GE0-4-4 192.168.1.9 30 192.168.1.10

Core-side media Eth-TrunkC1 192.168.1.13 30 192.168.1.14

Eth-TrunkC2 192.168.1.17 30 192.168.1.18

Eth-TrunkC3 192.168.1.21 30 192.168.1.22

Eth-TrunkC4 192.168.1.25 30 192.168.1.26

The following figure shows the allocation of interface addresses at the access side.

10GE SFP+

1GE SFP

Access

Network

Router 1 Router 2

Eth-TrunkA3 10.1.1.13/30

Eth-TrunkA4 10.1.1.17/30

Eth-TrunkA1 10.1.1.5/30

Eth-TrunkA2 10.1.1.9/30

Access-side signaling and mediaAccess-side media

Eth-

trunkA1Eth-

trunkA3

Eth-

trunkA2Eth-

trunkA4

The following figure shows the allocation of interface addresses at the core side.





45

10GE SFP+

1GE SFP

Core Network

Router 1 Router 2

Eth-TrunkC3 192.168.1.21/30

Eth-TrunkC4 192.168.1.25/30

GE0-1-4 192.168.1.5/30

Eth-TrunkC1 192.168.1.13/30

Eth-TrunkC2 192.168.1.17/30

GE0-4-4 192.168.1.9/30

Core-side signalingCore-side media

Eth-

trunkC1

Eth-

trunkC3

Eth-

trunkC2

Eth-

trunkC4

Every port requires an address that is on the same network segment as the

interconnected device. It is recommended that the addresses to be allocated be on the

minimum network segments with the mask length of 30. The number of required

addresses depends on the user capacity, as described in Table 4-22.

User Capacity

Number of Service Addresses

Number of Interface Addresses

Remarks

≤ 200,000

users

(Two

SPUA0s)


address x 1

Access-side media

address x 1

Core-side signaling

address x 5

Core-side media

address x 1

Access-side

interface x 2

Core-side

signaling

interface x 2

Core-side media

interface x 2

Once a 10GE port is

degraded to a GE port,

the access-side or

core-side traffic per SPU

must be no greater than

2.4 Gbit/s.

Every 40,000 users must

be allocated with one

core-side signaling

address.




address and one






46

User Capacity



Remarks

≤ 500,000

users

(Four

SPUA0s)


address x 1

Access-side media

address x 3

Core-side signaling

address x 13

Core-side media

address x 3

Access-side

interface x 2

Core-side

signaling

interface x 2

Core-side media

interface x 2

Once a 10GE port is


the access-side or



2.4 Gbit/s.

3. Local route planning


configuration is simple and you only need to add an equivalent route to every port. The

following table lists the specific routing entries.

Destination Network



Priority

Access

network

10.0.0.0 255.0.0.0 10.1.1.6 60

10.0.0.0 255.0.0.0 10.1.1.10 60

10.0.0.0 255.0.0.0 10.1.1.14 60

10.0.0.0 255.0.0.0 10.1.1.18 60

Core-side

signaling

address

192.168.2.0 255.255.255.0 192.168.1.6 60

192.168.2.0 255.255.255.0 192.168.1.10 60

Core-side

media address

192.168.0.0 255.255.0.0 192.168.1.14 60

192.168.0.0 255.255.0.0 192.168.1.18 60

192.168.0.0 255.255.0.0 192.168.1.22 60

192.168.0.0 255.255.0.0 192.168.1.26 60

4. Route planning on the peer end

On the routers interconnected with the SE2900, configure routes that are destined for

SE2900 service addresses and have the same priority.

Static route configuration on router 1





47

Destination Network Destination Network Segment


Priority


address

10.1.1.1 255.255.255.255 10.1.1.5 60

Access-side media

address 10.1.1.2 255.255.255.255 10.1.1.5 60

10.1.1.3 255.255.255.255 10.1.1.13 60

Core-side signaling

address

192.168.1.1 255.255.255.255 192.168.1.5 60

Core-side media address 192.168.1.2 255.255.255.255 192.168.1.1

3

60

192.168.1.3 255.255.255.255 192.168.1.2

1 60


Destination Network Destination Network Segment


Priority


address 10.1.1.1 255.255.255.255 10.1.1.9 60

Access-side media

address

10.1.1.2 255.255.255.255 10.1.1.9 60

10.1.1.3 255.255.255.255 10.1.1.17 60

Core-side signaling

address

192.168.1.1 255.255.255.255 192.168.1.9 60

Core-side media address 192.168.1.2 255.255.255.255 192.168.1.1

7 60

192.168.1.3 255.255.255.255 192.168.1.2

5

60

4.4.5 Reliability

LACP is used to ensure the reliability of the dual-plane load balancing network using

Eth-trunk interfaces. When creating an Eth-trunk interface, configure the Eth-trunk to work in

LACP mode so that LACP can be used to negotiate and monitor the link status between

member ports.





48

4.5 Single-plane Load Balancing Networking Using Eth-Trunk Interfaces


1. The SE2900 is directly connected to routers.

2. The router uses the LAG function to implement port convergence for the SE2900.

3. The route is deployed on a single-plane network. Ports on the SE2900 are connected to

two forwarding boards on the router.


Figure 4-15 Access-side networking where single-plane load balancing using Eth-trunk interfaces

is implemented

10GE SFP+

1GE SFP

Access

Network

Router

Access-side

signaling and media

Eth-

trunkA1





49

10GE SFP+

1GE SFP

Access

Network

Access-side media

Router

Eth-

trunkA2

Access

Network

As shown in the preceding figures, no 10GE port is available on the access network.

Therefore, the 10GE optical interfaces available on the SE2900 must be degraded to GE

optical interfaces. In this case, three ports on each board at the access side must be used to

ensure that all service traffic can be processed. To simplify the configuration, Eth-trunk

interfaces are recommended for the connection between the SE2900 and routers/switches. The

connected router must be deployed in load-balancing mode on the access network where only

a single plane forwards service packets. The router supports the Eth-trunk function. In this

case, use the specified traffic model to calculate the number of required cables on each board

based on the traffic volume and distribution. Note that 80% of the product of the port quantity

and port bandwidth must be no less than the service bandwidth required by the specified

board.

If a base board supports a maximum number of 20000 concurrent audio sessions, the codec type is G.711,

the packetization time is 20 ms, and the Ethernet bandwidth required by a session flow is 95.2 kbit/s, the

bandwidth required is 20000 x 95.2 kbit/s = 1.904 Gbit/s. In this case, only three GE ports need to be

configured on the board to access access-side media traffic. These specifications can also be used to

calculate the high bandwidth required by video traffic.




This networking solution consists of the following items:

1. Services in slots 1 and 4 back up each other. Services in slots 3 and 6 back up each other.





50






2. GE0-1-0, GE0-1-1, and GE0-1-5 in slot 1 and GE0-4-0, GE0-4-1, and GE0-4-5 in slot 4

are bundled into an Eth-trunk interface, which access the access-side signaling traffic and

partial access-side media traffic. Note that the access-side media traffic must be no

greater than 1.6 Gbit/s. If a separate Rf or Rx interface is required, ports GE0-1-5 and


3. GE0-3-0, GE0-3-1, and GE0-3-5 in slot 3 and GE0-6-0, GE0-6-1, and GE0-6-5 in slot 6

are bundled into an Eth-trunk interface, which access the access-side media traffic of no

greater than 2.4 Gbit/s.

4. Each pair of boards is configured with a media address. Media traffic is evenly distributed

among all ports of this pair of boards using the Eth-trunk function. Figure 4-16Error! No

bookmark name given. shows the detail.


10GE SFP+

1GE SFP


5. On the routers interconnected with the SE2900, load balancing needs to be performed for






51


10GE SFP+

1GE SFP

Access

Network

1/2 traffic






52


Figure 4-18 Core-side networking where single-plane load balancing using Eth-trunk interfaces is

implemented

10GE SFP+

1GE SFP

Core Network


Router

Eth-

trunkC2Eth-

trunkC1

10GE SFP+

1GE SFP

Core Network

Core-side

media

Router

Eth-

trunkC3





53


networking, signaling and media traffic must be separately processed. Therefore, additional

GE ports in slots 1 and 4 of subrack 0, which are GE0-1-4 and GE0-4-4, are required in

core-side networking to transmit signaling traffic. Eth-trunk is optional for these GE ports and

is used in the preceding example.


access-side networking. If a separate Rf or Rx interface is required, ports GE0-1-7 and


4.5.4 Data Planning

1. Port Planning

The number of required access-side and core-side ports can be directly calculated using

the configurator and network design tool. You can then allocate ports based on allocation

rules.

10GE SFP+

1GE SFP

01

02

03

04

05

06

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

ESU

Access-side signaling/media

Core-side media

Reserved

Core-side media (GE) / Rf7

5

6

2 3

0 1

Core-side signaling4

ISU

Access-side media (GE) / Rx

Access-side media

Core-side media

Reserved

Core-side media (GE)7

5

6

2 3

0 1

Reserved4

Access-side media (GE)

1. GE0-1-0 and GE0-4-0 are used to access access-side signaling traffic and some

media traffic.

2. GE0-1-4 and GE0-4-4 are used to access core-side signaling traffic. GE0-3-4 and

GE0-6-4 does not need to access core-side signaling traffic and therefore is

reserved.

3. Ports 0 and 1 in all slots are used to access access-side media traffic.

4. Ports 2 and 3 in all slots are used to access core-side media traffic.

5. A 10GE optical port can be degraded to a GE optical port if the media traffic rate on

the ISU is less than or equal to1.6 Gbit/s and that on the ESU is less than or equal to

2.4 Gbit/s. Ports 5 and 7 can be added to access access-side media traffic and

core-side media traffic respectively as the service traffic increases.

6. GE electrical ports are used if the access-side media traffic is less than or equal to

0.8 Gbit/s. In this case, only ports 0, 2, 4, and 6 are available.

7. Ports in slots 1 and 4, as well as ports in slots 3 and 6, work in active/standby or






54

Once the 10GE ports are degraded to GE ports, port planning for a fully configured

SE2900 is as follows:

Network Port Allocated Remarks

Access-side

signaling and media




interface can access signaling


and media traffic of no greater than

1.6 Gbit/s.

GE0-1-1

GE0-1-5

GE0-4-0

GE0-4-1

GE0-4-5

Access-side media GE0-3-0 These ports are bundled into an





GE0-3-1

GE0-3-5

GE0-5-0

GE0-5-1

GE0-5-5

Core-side signaling GE0-1-4 These ports are bundled into an





GE0-4-4

Core-side media GE0-1-2 These ports are bundled into an





GE0-1-3

GE0-1-7

GE0-4-2

GE0-4-3

GE0-4-7






GE0-3-3

GE0-3-7

GE0-5-2

GE0-5-3

GE0-5-7





55

2. Address Planning

This section assumes that the access-network address segment is 10.0.0.0/8, the

core-network media address segment is 192.168.0.0/16, and the core-network signaling

address segment is 192.168.2.0/24. The following table lists examples for the service

addresses and interface addresses to be planned.

1. Service addresses to be planned


Access-side

signaling address

10.1.1.1 This address is used to access UE registration

and call services. It must be bound to the HRU

process in slot 1.

Access-side

media address





10.1.1.3

Core-side

signaling address

192.168.1.1 This address must be bound to the HRU

process in slot 1. Every 40,000 UEs must be


Core-side media

address


core-side media address. Every 20,000



192.168.1.3

说明 Each SPUA0 that serves as the ISU supports a maximum of 20,000 concurrent calls. Each SPUA0 that is







that serves as the ISU requires a pair of media addresses, and each SPUA0 that serves as the ESU

requires two pairs of media addresses.








that serves as the ISU requires two pairs of media addresses, and each SPUA1 that serves as the ESU

requires three pairs of media addresses.

2. Interface addresses to be planned





56

Network Interface Allocated

Interface Address

Mask Peer Address

Access-side

signaling

GE0-1-0 10.1.1.5 30 10.1.1.6

GE0-4-0 10.1.1.9 30 10.1.1.10

Access-side

signaling and

media

Eth-TrunkA1 10.1.1.5 30 10.1.1.6

Eth-TrunkA2 10.1.1.9 30 10.1.1.10

Core-side

signaling

Eth-TrunkC1 192.168.1.5 30 192.168.1.6

Core-side media Eth-TrunkC2 192.168.1.13 30 192.168.1.14

Eth-TrunkC3 192.168.1.17 30 192.168.1.18

The following figure shows the allocation of interface addresses at the access side.

10GE SFP+

1GE SFP

Access

Network

Router

Eth-TrunkA3 10.1.1.9/30

Eth-TrunkA1 10.1.1.5/30

Access-side signaling and mediaCore-side media

Eth-

trunkA1Eth-

trunkA2

The following figure shows the allocation of interface addresses at the core side.





57

10GE SFP+

1GE SFP

Core Network

Router 1

Eth-TrunkC3 192.168.1.17/30

Eth-TrunkC1 192.168.1.5/30

Eth-TrunkC2 192.168.1.13/30


Eth-

trunkC1Eth-

trunkC3Eth-

trunkC2

Eth-

trunkC2

Every port requires an address that is on the same network segment as the

interconnected device. It is recommended that the addresses to be allocated be on the

minimum network segments with the mask length of 30. The number of required

addresses depends on the user capacity, as described in Table 4-22.

User Capacity



Remarks

≤ 200,000

users

(Two

SPUA0s)


address x 1

Access-side media

address x 1

Core-side signaling

address x 5

Core-side media

address x 1

Access-side

interface x 2

Core-side

signaling x 2

Core-side media

address x 2

Once a 10GE port is


the access-side or



2.4 Gbit/s.

Every 40,000 users must


core-side signaling

address.




address and one






58

User Capacity



Remarks

≤ 500,000

users

(Four

SPUA0s)


address x 1

Access-side media

address x 3

Core-side signaling

address x 13

Core-side media

address x 3

Access-side

interface x 2

Core-side

signaling x 2

Core-side media

address x 2

Once a 10GE port is


the access-side or



2.4 Gbit/s.

1. Local route planning


configuration is simple and you only need to add an equivalent route to every port. The

following table lists the specific routing entries.

Destination Network



Priority

Access

network

10.0.0.0 255.0.0.0 10.1.1.6 60

10.0.0.0 255.0.0.0 10.1.1.10 60

Core-side

signaling

address

192.168.2.0 255.255.255.0 192.168.1.6 60

Core-side

media address

192.168.0.0 255.255.0.0 192.168.1.14 60

192.168.0.0 255.255.0.0 192.168.1.18 60

2. Route planning on the peer end

On the routers interconnected with the SE2900, configure routes that are destined for

SE2900 service addresses and have the same priority.


Destination Network



Priority

Access-side

signaling

address

10.1.1.1 255.255.255.255 10.1.1.5 60





59

Destination Network



Priority

Access-side

media address

10.1.1.2 255.255.255.255 10.1.1.5 60

10.1.1.3 255.255.255.255 10.1.1.9 60

Core-side

signaling

address

192.168.1.1 255.255.255.255 192.168.1.5 60

Core-side

media address

192.168.1.2 255.255.255.255 192.168.1.13 60

192.168.1.3 255.255.255.255 192.168.1.17 60

4.5.5 Reliability

LACP is used to ensure the reliability of the single-plane load balancing network using

Eth-trunk interfaces. When creating an Eth-trunk interface, configure the Eth-trunk to work in

LACP mode so that LACP can be used to negotiate and monitor the link status between

member ports.

4.6 Active/Standby Networking


The SE2900 is directly connected to switches.

The switches are deployed on a dual-plane network where both planes can forward

service packets. The SE2900 selects one of the planes to forward service packets.





60


10GE SFP+

1GE SFP

Access

Network

LAN Switch 1 LAN Switch 2


Access-side media

Standby link for access-side signaling

and media

Standby link for access-side media

N x 2 links

As shown in the preceding network, two switches are deployed in load-balancing mode on the

access network. Service packets can be exchanged between the switches. In this situation, use

the specified traffic model to calculate the number of required cables on each board based on

the traffic volume and distribution. For details about the bandwidth calculation method, see

section 4.3.2 "Access-side Networking."









traffic. The two ports back up each other on the same network.

Every pair of boards has its own media service addresses. Port 0s on the two boards back

up each other and media traffic is sent over the active port.

10GE SFP+

1GE SFP

Mutual backup





61

The switches interconnected with the SE2900 send traffic to the active port on the

SE2900.

10GE SFP+

1GE SFP

Access Network



10GE SFP+

1GE SFP

Core Network


Core-side signaling

Core-side media

Standby link for core-side

signaling


media

N x 2 links


networking, signaling and media traffic must be separately processed. Therefore, an additional

GE port is required to transmit signaling traffic in core-side networking.

The active/standby port mode similar to that in access-side networking is used for media and

signaling traffic in core-side networking.





62

4.6.4 Data Planning

Port Planning

Port planning in active/standby networking is similar to that in dual-plane load balancing

networking. The difference is that static route-based load balancing is implemented to achieve

backup in dual-plane load balancing networking and active/standby ports are used to achieve

backup in active/standby networking.



10GE SFP+

1GE SFP

01

02

03

04

05

06

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6





Reserved


capacity)Core-side media port (small user capacity)7

6

5

2 3

0 1

4

0
















the upper limit.





63


Traffic Type Port Allocated Backup Port Remarks

Access-side

signaling

GE0-1-0 GE0-4-0 Access-side signaling traffic

shares the same port with

access-side media traffic.

Access-side

media

GE0-1-0 GE0-4-0 Each board supports a

maximum of 16 Gbit/s

traffic. GE0-3-0 GE0-6-0

Core-side

signaling

GE0-1-4 GE0-4-4

Core-side media GE0-1-2 GE0-4-2

GE0-3-2 GE0-6-2

Address Planning



192.168.2.0/24. Table 4-13 and Table 4-14 list examples for the service addresses and

interface addresses to be planned.



Access-side

signaling address

10.1.1.1 This address is used to access UE registration and

call services. It must be bound to the HRU

process in slot 1.

Access-side media

address





10.1.1.3

Core-side

signaling address

192.168.1.1 This address must be bound to the HRU process

in slot 1. Every 40,000 UEs must be


Core-side media

address





192.168.1.3





64


Traffic Type Port Allocated

Backup Port

Interface Address

Mask Peer Address

Access-side

signaling

GE0-1-0 GE0-4-0 10.1.1.5 30 10.1.1.6

Access-side

media

GE0-1-0 GE0-4-0 10.1.1.5 30 10.1.1.6

GE0-3-0 GE0-6-0 10.1.1.9 30 10.1.1.10

Core-side

signaling

GE0-1-4 GE0-4-4 192.168.1.5 30 192.168.1.6

Core-side

media

GE0-1-2 GE0-4-2 192.168.1.9 30 192.168.1.10

GE0-3-2 GE0-6-2 192.168.1.13 30 192.168.1.14


10GE SFP+

1GE SFP

GE0-3-0 10.1.1.9/30

GE0-1-0 10.1.1.5/30

Access

Network



Access-side media


and media






65


10GE SFP+

1GE SFP

GE0-3-2 192.168.1.13/30

GE0-1-4 192.168.1.5/30

GE0-1-2 192.168.1.9/30

Core Network


Core-side signaling

Core-side media

Standby link for core-side signaling

Standby link for core-side media

Every pair of active/standby ports requires an address that is on the same network segment as

the interconnected device. The number of required addresses depends on the user capacity, as

described in Table 4-15.


User Capacity



Remarks

≤ 250,000

(one pair of

the SPUA0s)

Access-side


Access-side media

address x 1

Core-side signaling

address x 7

Core-side media

address x 1


Core-side signaling

address x 1

Core-side media

address x 1

The access-side or



equal to 8 Gbit/s.

Every 40,000 UEs must


core-side signaling

address.




address and one

core-side media

address.

≤ 500,000

(one pair of

the SPUA1s)

Access-side


Access-side media


Core-side signaling

address x 1

The access-side or



equal to 8 Gbit/s.





66

User Capacity



Remarks

address x 2

Core-side signaling

address x 13

Core-side media

address x 2

Core-side media

address x 1

≤ 1,200,000

(two pairs of

the SPUA1s)

Access-side


Access-side media

address x 5

Core-side signaling

address x 30

Core-side media

address x 5


Core-side signaling

address x 1

Core-side media

address x 2

The access-side or



equal to 8 Gbit/s.



Access-side media

address x 11

Core-side signaling

address x 65

Core-side media

address x 11


Core-side signaling

address x 1

Core-side media

address x 4

Dual-subrack cascading



Access-side media

address x 17

Core-side signaling

address x 100

Core-side media

address x 17


Core-side signaling

address x 1

Core-side media

address x 6

Three-subrack

cascading








Priority

Access-side address 10.0.0.0 255.0.0.0 10.1.1.6 60

10.0.0.0 255.0.0.0 10.1.1.10 60





67



Priority

Core-side signaling

address

192.168.2.0 255.255.0.0 192.168.1.6 60

Core-side media

address

192.168.0.0 255.255.0.0 192.168.1.10 60

192.168.0.0 255.255.0.0 192.168.1.14 60


On the servers and routers interconnected with the SE2900, configure routes that are destined

for SE2900 service addresses and have the same priority.

Table 4-17 Static route configuration on routers



Priority

Access-side

signaling address

10.1.1.1 255.255.255.255 10.1.1.5 60

Access-side media

address

10.1.1.2 255.255.255.255 10.1.1.5 60

10.1.1.3 255.255.255.255 10.1.1.9 60

Core-side

signaling address 192.168.1.1 255.255.255.255 192.168.1.5 60

Core-side media

address

192.168.1.2 255.255.255.255 192.168.1.9 60

192.168.1.2 255.255.255.255 192.168.1.13 60

4.6.5 Reliability

In active/standby networking, ARP probe must be configured for every physical link to ensure

the reliability of the associated static route. ARP probe works in either of the following

modes:

ARP gateway probe mode: The active and standby ports periodically send ARP requests

to the peer device to detect the gateway address. An IP address must be configured on the

standby port to implement the probe.

ARP master and slave probe mode: The active port sends ARP requests to detect the

gateway address, whereas the standby port sends ARP requests to detect the address of

the active port.

In active/standby networking, the ARP master and slave probe mode is recommended to save

IP addresses. Table 4-18 lists the ARP probe to be configured.





68

Table 4-18 ARP probe to be configured


GE0-1-0 10.1.1.5 10.1.1.6 ARP probe needs to be enabled

for every pair of ports.

GE0-3-0 10.1.1.9 10.1.1.10

GE0-1-4 192.168.1.5 192.168.1.6

GE0-1-2 192.168.1.9 192.168.1.10

GE0-3-2 192.168.1.13 192.168.1.14

4.7 Interconnection with VRRP-enabled Routers


The SE2900 is connected to VRRP-enabled routers through switches.

Ports on VRRP-enabled routers work in active/standby mode. The active VRRP link is

used to forward service packets.


10GE SFP+

1GE SFP

Access

Network

Router 1 Router 2


Access-side media

Standby link for access-side

signaling and media


N x 2 links

VRRP





69

In this solution, VRRP is enabled on both the access-side network. The devices

interconnected with the SE2900 are VRRP-enabled routers. A Layer 2 network must exist

between the SE2900 and routers. The routers must be able to perform Layer 2 switching using

an external switch or the embedded Layer 2 switching function. The SE2900 can exchange

packets with the switches or the interconnected router on the active VRRP link. In this

situation, use the specified traffic model to calculate the number of required cables on each

board based on the traffic volume and distribution. For details about the bandwidth

calculation method, see section 4.3.2 "Access-side Networking."









traffic. The two ports back up each other on the same network.

Every pair of boards has its own media service addresses. Port 0s on the two boards back

up each other and media traffic is sent over the active port.

10GE SFP+

1GE SFP

Mutual backup

Router 1 Router 2

VRRP

MasterSlave

The switches interconnected with the SE2900 forward traffic sent by the SE2900 to the

master router and traffic sent by the master router to the active port on the SE2900.





70

10GE SFP+

1GE SFP

Router 1 Router 2

VRRP

MasterSlave


10GE SFP+

1GE SFP

Core-side signaling

Core-side media


signaling


Access

Network

Router 1 Router 2

N x 2 links

VRRP


networking, signaling and media traffic must be separately processed. Therefore, an additional

GE port is required to transmit signaling traffic in core-side networking.

The active/standby port mode similar to that in access-side networking is used for media and

signaling traffic in core-side networking.





71

4.7.4 Data Planning

Port Planning

The number of required ports and number of addresses are the same as those in active/standby

networking. In active/standby networking, service packets are forwarded by the most

appropriate next-hop device on the Layer 2 network according to routing rules because

multiple next-hop devices exist. Compared with active/standby networking, when the SE2900

is interconnected with VRRP-enabled routers, the next-hop device of the SE2900 is the

master VRRP-enabled router.



10GE SFP+

1GE SFP

01

02

03

04

05

06

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6

1

0

3

2

5

4

7

6





Reserved

Access-side signaling media port (small user

capacity)Core-side media port (small user capacity)7

6

5

2 3

0 1

4

0
















the upper limit.





72


Traffic Type Port Allocated Backup Port Remarks

Access-side

signaling

GE0-1-0 GE0-4-0 Access-side signaling traffic

shares the same port with

access-side media traffic.

Access-side

media

GE0-1-0 GE0-4-0 Each board supports a

maximum of 16 Gbit/s

traffic. GE0-3-0 GE0-6-0

Core-side

signaling

GE0-1-4 GE0-4-4

Core-side media GE0-1-2 GE0-4-2

GE0-3-2 GE0-6-2

Address Planning



192.168.2.0/24. Table 4-20 and Table 4-21 list examples for the service addresses and

interface addresses to be planned.



Access-side

signaling address

10.1.1.1 This address is used to access UE registration and

call services. It must be bound to the HRU

process in slot 1.

Access-side media

address





10.1.1.3

Core-side

signaling address

192.168.1.1 This address must be bound to the HRU process

in slot 1. Every 40,000 UEs must be


Core-side media

address





192.168.1.3





73


Traffic Type

Port Allocated

Backup Port

Interface Address

Mask Peer Address

Access-side

signaling

GE0-1-0 GE0-4-0 10.1.1.5 30 10.1.1.6

Access-side

media

GE0-1-0 GE0-4-0 10.1.1.5 30 10.1.1.6

GE0-3-0 GE0-6-0 10.1.1.9 30 10.1.1.10

Core-side

signaling

GE0-1-4 GE0-4-4 192.168.1.5 30 192.168.1.6

Core-side

media

GE0-1-2 GE0-4-2 192.168.1.9 30 192.168.1.10

GE0-3-2 GE0-6-2 192.168.1.13 30 192.168.1.14

In VRRP networking, the peer addresses of the SE2900 are all virtual VRRP addresses.


10GE SFP+

1GE SFP

GE0-3-0 10.1.1.9/30

GE0-1-0 10.1.1.5/30


Access-side media


and media


Access

Network

Router 1 Router 2

VRRP

N x 2 links





74


10GE SFP+

1GE SFP

GE0-3-2 192.168.1.13/30

GE0-1-4 192.168.1.5/30

GE0-1-2 192.168.1.9/30

Core-side signaling

Core-side media

Standby link for core-side signaling


Access

Network

Router 1 Router 2

N x 2 links

VRRP

Every pair of active/standby ports requires an address that is on the same network segment as

the interconnected device. The number of required addresses depends on the user capacity, as

described in Table 4-22.


User Capacity



Remarks

≤ 250,000 Access-side


Access-side media

address x 1

Core-side signaling

address x 7

Core-side media

address x 1


Core-side signaling

address x 1

Core-side media

address x 1

The access-side or

core-side traffic per board

is less than or equal to 8

Gbit/s.

Every 40,000 UEs must


core-side signaling

address.




address and one core-side

media address.

≤ 500,000 Access-side


Access-side media


Core-side signaling

address x 1

The access-side or







75

User Capacity



Remarks

address x 2

Core-side signaling

address x 13

Core-side media

address x 2

Core-side media

address x 1

Gbit/s.



Access-side media

address x 5

Core-side signaling

address x 30

Core-side media

address x 5


Core-side signaling

address x 1

Core-side media

address x 2

The access-side or



Gbit/s.



Access-side media

address x 11

Core-side signaling

address x 65

Core-side media

address x 11


Core-side signaling

address x 1

Core-side media

address x 4

Dual-subrack cascading



Access-side media

address x 17

Core-side signaling

address x 100

Core-side media

address x 17


Core-side signaling

address x 1

Core-side media

address x 6

Three-subrack cascading








Priority

Access-side

address

10.0.0.0 255.0.0.0 10.1.1.6 60

10.0.0.0 255.0.0.0 10.1.1.10 60





76



Priority

Core-side

signaling address

192.168.2.0 255.255.0.0 192.168.1.6 60

Core-side media

address

192.168.0.0 255.255.0.0 192.168.1.10 60

192.168.0.0 255.255.0.0 192.168.1.14 60


On the servers and routers interconnected with the SE2900, configure routes that are destined

for SE2900 service addresses and have the same priority.

Table 4-24 Static route configuration on routers



Priority

Access-side

signaling address

10.1.1.1 255.255.255.255 10.1.1.5 60

Access-side media

address

10.1.1.2 255.255.255.255 10.1.1.5 60

10.1.1.3 255.255.255.255 10.1.1.9 60

Core-side

signaling address 192.168.1.1 255.255.255.255 192.168.1.5 60

Core-side media

address

192.168.1.2 255.255.255.255 192.168.1.9 60

192.168.1.2 255.255.255.255 192.168.1.13 60

4.7.5 Reliability

In active/standby networking, ARP probe must be configured for every physical link to ensure

the reliability of the associated static route. ARP probe works in either of the following

modes:

ARP gateway probe mode: The active and standby ports periodically send ARP requests

to the peer device to detect the gateway address. An IP address must be configured on the

standby port to implement the probe.

ARP master and slave probe mode: The active port sends ARP requests to detect the

gateway address, whereas the standby port sends ARP requests to detect the address of

the active port.

In active/standby networking, the ARP master and slave probe mode is recommended to save

IP addresses. Table 4-25 lists the ARP probe to be configured.





77

Table 4-25 ARP probe to be configured


GE0-1-0 10.1.1.5 10.1.1.6 ARP probe needs to

be enabled for every

pair of ports.

GE0-3-0 10.1.1.9 10.1.1.10

GE0-1-4 192.168.1.5 192.168.1.6

GE0-1-2 192.168.1.9 192.168.1.10

GE0-3-2 192.168.1.13 192.168.1.14

4.8 IPv6 Networking

4.8.1 IPv6 UE Accessing an IPv4 Core Network

Figure 4-23 Networking for an IPv6 UE accessing an IPv4 core network

Core network

Access network CSCF

Access network

CCF

SE2900

IPv4

UE A

UE B

UE C

UE D

UE E

NMSClient U2000

IPv4

DNS

IPv6

UMG

IPv4

As IPv4 addresses are about to be exhausted and a large number of IPv4 addresses are

required on the access network, upgrading the access network to support IPv6 is a major

concern. As shown in Figure 4-23, after the access network is upgraded, UEs on the access

network can use IPv6 addresses to access the core network. Currently, the core network is an

IPv4 network, and the SE2900 is deployed at the border of the core network to implement

IPv4/IPv6 interworking. The networking is the same as that for IPv4 UE accessing an IPv4

core network. Available networking schemes for the SE2900 are dual-plane load-balancing

networking, Eth-trunk networking, and active/standby networking. IPv6 UEs on the access

network are supported.





78

4.8.2 IPv4/IPv6 UE Accessing an IPv6 Core Network

Figure 4-24 Networking for an IPv4/IPv6 UE accessing an IPv6 core network

Core network

Access network

CSCF

Access network

CCF

SE2900IPv4

UE A

UE B

UE C

UE D

UE E

NMSClientU2000

IPv4

DNS

IPv6

UMG

SE2900

Access network

UE F

UE G

IPv4

IPv4

IPv6/

IPv4

If the core network is an IPv6 network or upgraded to an IPv6 network as shown in Figure

4-24, UEs on the access network can access the IPv6 core network using IPv4 and IPv6

addresses. The SE2900 is deployed at the border of the core network to implement the

IPv6/IPv6 and IPv4/IPv6 interworking. The access-side and core-side networking is the same

as those for an IPv4 UE accessing an IPv4 core network. Available networking schemes for

the SE2900 are dual-plane load-balancing networking, Eth-trunk networking, and

active/standby networking.

4.8.3 IPv4/IPv6 Core Network Interworking

Figure 4-25 Networking for IPv4/IPv6 core network interworking

Carrier A

IP-PBX

核心网CSCF

Carrier C

核心网

CSCF

CCF

SE2900

NMSClientU2000

DNS

UMG

IPv6/IPv4

核心网CSCF

Carrier A

Carrier B

IPv6

IPv4





79

The SE2900 supports interworking between an IPv6 core network and an IPv6 network.

Figure 4-25 shows the networking for interworking between an IPv6 core network and an

IPv6 network. The SE2900 is deployed at the border of the core network to implement

IPv4/IPv4, IPv4/IPv6, and IPv6/IPv6 interworking. The networking is the same as that for

IPv4 core network interworking. Available network schemes for the SE2900 are dual-plane

load-balancing networking, Eth-trunk networking, and active/standby networking.

4.9 VRF Networking

VRF can be used in the preceding networking solutions to achieve network isolation and

network address overlapping. In VRF networking, ports, interfaces (main interfaces and

subinterfaces), interface addresses, and service addresses must be bound to associated VRF

instances. No special requirement exists for VRF networking. Signal addresses and media

address can separated into different networks by associated with different VRF instances.


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5 Networking Limitations

5.1 Port 10GE ports on the SPU do not support the switching between 10GE and GE.

One active port maps one auxiliary port (standby port).

5.2 IPv4 Address

The IPv4 addresses of interfaces on a pair of active/standby boards must be on different

network segments.

5.3 IPv6 Address

1. The IPv6 addresses of interfaces on a pair of active/standby boards must be on different

network segments.

2. IPv6 stateless address autoconfiguration is not supported.

3. IPv6 routing discovery packets and IPv6 router advertisement packets are not supported.

4. IPv6 ND proxy is not supported. To implement IPv6 ND, configure static routes from

the neighboring device to the service IP addresses of the SE2900.

5.4 Routing

Service packets received over an interface cannot be forwarded between boards before the

service is processed.

5.5 BFD

1. On the SE2900, BFD complies with RFC 5880 with the version of 1. Devices that

support RFC 5880 with the version of 0 do not support BFD interworking.

2. BFD sessions do not support the echo function on the local system or the echo response to the remote system.


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3. BFD sessions support the query mode on the remote system instead of the local system.

4. BFD control packets do not support authentication.

5. If the local IP address is a service or tunnel IP address, a single-hop BFD session cannot

be established.

6. Before configuring the relationships between the static route and BFD sessions, users

must configure the BFD sessions on the local and peer systems. Otherwise, the static

route to be bound becomes inactive because the BFD session is not configured on the

peer system and the local BFD session fails to be negotiated for a long time.

7. It is recommended to bind a static route to a single-hop BFD session. If the static route is

bound to a multi-hop BFD session, BFD packets fail to be transmitted when a BFD

session becomes Down and a resource deadlock occurs. If the static route needs to be

bound to a multi-hop BFD session, it is recommended to add static route configurations

on the local system so that the BFD session detection packets use a specified interface to

perform detection and BFD sessions are not interrupted upon data-plane process

switching on the local system.


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Acronyms and Abbreviations

A

A-SBC access session border controller

AG access gateway

ARP Address Resolution Protocol

ATS advanced telephony server

B

BFD bidirectional forwarding detection

C

CCF charging collection function

CS circuit switched

CSCF call session control function

D

DNS domain name server

F

Fixed BB fixed broadband

G

GGSN gateway GPRS support node

H

H.323 GW H.323 gateway





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I

I-SBC interworking session border controller

IPv6 Internet Protocol version 6

L

LACP link aggregation control protocol

LAG link aggregation group

LTE long term evolution

M

MGW media gateway

MME mobility management entity

N

NAT Network Address Translation

NGN next generation network

ND neighbor discovery

P

P-GW packet data network gateway

PCRF policy and charging rules function

PS packet switched

Q

QoS quality of service

R

RCS rich communication suite

U

UE user equipment

V





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VoBB voice over broadband

VoLTE voice over LTE

VRRP Virtual Router Redundancy Protocol

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