access technologies and convergence access technologies plays an important role within network...

Access Technologies and

convergence Access technologies plays an important

role within network convergence• Stage 1: Integration of PSTN /ISDN/IP

terminals and additional support of broadband data services

• Stage 2: All-IP based, unified interface to all services and terminals

Vaculík Martin 2006

Access Technologies and convergence

Stage 1 main Feature• Shifting the subscriber’s port on the edge

on Network • All media and signalling conversion

performed in distributed Media gateways MG

• MGs controlled by MG controller(s) • MG use IP connectivity via ETH/PDH/SDH• Interworking to the existing ISDN via MG



TrunkingGateway

SS7

ISDN

AccessNetwork

SignallingGateway

AccessGateway

ResidentialGateway

Media GatewayController

Media GatewayController

SIP-T

MEGACO/MGCP

SIGTRAN

MEGACO/MGCP

MEGACO/MGCP

IP CORE NETWORK

SOFTSWITCH

IP PHONES

VARIOUS TYPES OF SUBSCRIBER AND NETWORK MGs



• MEDIA GATEWAY TYPICAL ARCHITECTURE (LITESPAN 1540 ALCATEL)

16XE1

4xE1- IMA, E3

STM1/4

ETHERNETBRIDGE

ETH10/100BaseT

NARROWBAND TDM BUS 2 X 51 Mb/s

BROADBAND ATMBUS 2 X 155 Mb/s

TRANSPORTSDH/PDH

NARROWBANDCONTROLLER

BROADBANDCONTROLLER

ETH10/100BaseT, 100FXBB LINECARDs

NB LINECARDs

TEST,ALARM,RINGER.

ADSLSHDSLIMA E1

POTSISDNANALOG LLDIGITAL LLHDSLSHDSL

VoIPSERVER

SERVER BUS2X16Mb/s


• KEY FEATURES:

• SUBSCRIBERs POTS, UK/2B1Q and U2M Interface

• ADSL as a STANDARD EQUIPMENT OF PORTS– (SLOVAKIA: NOVADAYS LIMITED TO APPROX. 3/0.5

Mb/s DUE TO SELF-INSTALATION.......)

• VoDSL SUPPORT• ISDN NETWORK VIA V5.1 AND V5.2• NGN NETWORK SIDE: FROM N x E1 copper TO

STM 1/4 optical• MEGACO/H.248 AND IPoA• ADDRESS TRANSLATION POTS/IP (VoIP SERVER)


STAGE 2 - ALL IP BROADBAND ACCESS• REDUCING PPP AND/OR ATM over ADSL METRO-ETHERNET:• A VARIOUS PROTOCOLS POSSIBLE INSIDE,• ONLY IP on THE UNI SUBSCRIBER SIDE

TERMINAL

CPEHIGHER LAYERS

IP

ETHERNET

Physical Layer

IP

ETHERNET

PhysicalLayer

PhysicalLayer

IP

ETHERNET

PhysicalLayer

PhysicalLayer

HIGHER LAYERS

IP

ETHERNET

PhysicalLayer

PhysicalLayer

ETH,ATM,...

METROETHERNET

COUNI


UNI PHYSICAL LAYER: ETHERNET over FIRST MILE (EFM)

ETHERNET Media Independent Interface

MAC Full duplex

1000BASE-XPHY

EoxDSLPHY

EPONPHY

FIBREPMD

COPPERPMD

FIBREPMD

EFM OVER COPPER

• 2Base-TL SHDSL, 2+2 Mb/s, 2700 m

• 10Base-TS VDSL, 10+10 Mb/s, 750 m

• 100/1000Base-X

sm FIBRE, DIPLEX/DUPLEX, 10 km

• ETHERNET OVER PON


EPON:CLASSICAL MULTIPOINT TDM/TDMA BASED PONTOTAL CAPACITY UP TO 1 Gb/sAPPROX. 1 Mb/s at UNI, 10/20 km RANGE


ETHERNET VIRTUAL CONNECTION SERVICEETH FRAME TRANSMITTED TRANSPARENTLY

(SAME MAC ADDR., SAME PAYLOAD)

MULTIPOINT: ETHERNET LAN SERVICEPOINT-TO-POINT: ETHERNET LINE SERVICE

• BEST EFFORT or • GUARANTEED QoS

Committed Information Rate CIR Committed Burst Size CBS Excess Information Rate EIR Excess Burst Size EBS Jitter, Packet Loss, Delay

Access Technologies and convergenceEthernet virtual connection QoS

• BANDWITH PROFILE CONTROL

TOKENS

CIRRATE

EIRRATE

CBS

EBS

TOKENS

>CBS

DISCARD

>EBS

<= CBS

<=EBS

TWO RATE TREE COLOR Mechanism

DUAL LEAKY BUCKET

CIR meet

EBS meet

Discard


Circuit Emulation Service over Ethernet (CESoE)

• Synchronous traffic emulation

– TDM Access Line Service (Access to ISDN)

– TDM Line Service (Private TDM Network)

– E Line (Private Circuit emulation)

– Hybrid Line • Non structured(transparent) • Structured Mode (only Payload, no alarms)


Technical requirements:Low and constant delay (up to 30 ms e2e)

Min. Packet lossG.826 ITU Rec.: E1: ES =7E-3/4E-2; SYNC Clock & Timing reconstruction

Packetisation delay - 1 ms E1 - 256 B, E3 - 1024 B

Network delay - up to 25 ms (no EC necessary)

Jitter delay - up to 10 msPacket Loss < 1E-6 to reach G.826 ES values


Timing reconstruction - TDM Output lock to:• TDM Input• External Clock gen.• Free running Oscillator• Ethernet input

CESoE Frame Structure:L- Near End ERRR - Far End ERRM - ERR CodeFRG - Fragment StatusLEN - Length of Stuffing VLAN Tag (Optional)

0x88D8 CESoE Service

20 bits Emulated CIrcuit iDent.

0x102 Reserved

4 1 1 2 2 6 16

RES L R M FRG LEN SqNCESoE Control Word

RTP (Optional)

TDM PAYLOAD


Voice over DSL -drive toward voice/data convergence - Step 1

POTS/ISDN/DATA services mixed via IADIAD main functions:• Termination of the user interfaces (POTS, ISDN)• ATM AAL2 (de)multiplexing• Voice handling function (compression, echo

cancellation)• Generation of (POTS) or relaying DSS1 signalling

towards the voice gateway • Management from the gateway via an in-band

interface


Transfer mode - ATM AAL2 Loop emulationVoice switching - TDM switching network or

Call Server (Softswitch)

DATA

VOICE


Voice gateway functions:

• Termination of the voice circuits• ATM AAL2 (de)multiplexing to/from a single ATM

VC • Voice handling (compression, echo cancellation)• IAD to voice gateway signalling termination and

call control• On-demand traffic concentration of the voice

channels• Connectivity to a LEX via an open interface V5.x• Management of the IADs via an in-band interface


All Digital Loop: NT&VGW Integration– ISDL, ADSL or SHDSL access– So/a,b/10BaseT interfaces– emergency power feeding– Wi-Fi AP can be integrated

Step 2: Voice over IPIAD can remain unchanged, LEX replaced by Call

server - SoftswitchT-Com Slovakia: „I‘m calling over IP“ service, Virtual

“IP Office” service - 068xxxx numbering, approx. 40 % of the analog line cost, unbounded access

Transport technologies and convergence

• Present Core transport network: – SDH up to STM 16/64– TDM/ATM/IP mapping– High resilience and short recovery time

(<50ms)– perfect OAM and network management

– 99.999 % Reliability (5 min per Year outage)

Continuous upgrade of properties, e.g.:– Generic Framing Procedure– Virtual Concatenation– Link Capacity Adjustment Scheme


Generic Framing Procedure - generic mechanism to transport any client signal (IP/PPP, Ethernet MAC, Fibre Channel,...) over fixed data-rate optical channels

• point-to-point and ring applications• length/HEC-based frame delineation mechanism

Two mapping modes:• Frame-mapped GFP-F: maps the entire client

frame into one GFP frame• Transparent-mapped GFP –T: transport of block-

coded client signals


Encapsulation of frame/packet based data flow

Core HDR Payload HDR GFP Payload

Ctrl

FCS

Flag Addr PPP type PPP Info FCS

FCSETH PHY MAC IP Payload Ethernet Frame

PPP/HDLC Frame

GFP Frame

Payload HDR

User Payload IdentifierType of HECSpareGFP Extension HEC

PLength HDR Check PAYLOAD FCS

PTI PFI EXI


Concatenation - a more efficient way to broke a fix Container capacity assignment

Arbitrary contiguous concatenation:• custom sized bandwidth but the network • supports this bandwidth as a single entity• all intermediate nodes must support this feature

Virtual Concatenation: custom sized bandwidth but• Virtual containers create a LOGICAL group and• can be routed independently• Traffic (de)segmentation on a customer terminals


Link Capacity Adjustment scheme:Capacity adjustment possible during the

transport without traffic breakdownThe bandwidth tuning based on:• Quality of Service (QoS) parameters • Bandwidth on demand (time-of-day

demands, seasonal,...)• Load Balancing – to split the traffic load

between different points in the network• Inherently bursty traffic transmission


Support for LCAS: located in the VC source/sink adaptation functions only

• a two-way handshake signalling protocol used

• Synchronisation of changes: a control packet sequence of H4 Path overhead bytes

• control packet describes the state of the link during the next control packet

• Service Level Agreements (SLAs) guarantee • Controlled by Network and Element

Management Systems (NMS/EMS)


1GBE or 10GBE: almost all parameters worst

than SDH (exception - No IP/frame mapping

necessary)

Restoration techniques in std.IP networks:from several seconds to minutes ....• automatic protection switching (APS) • and virtual router redundancy protocol (VRRP)

continuously exchange of the redundant forwarding table

QoS supported in the Integrated Services (IntServ) paradigm by means of the Resource ReSerVation Protocol (RSVP)


Label switching - more effective routing & redundancy offering tool

Packet&Frame L2 Switching/L3 RoutingComponents: • Edge Label switch routers (ELSR) • Core Label Switch Routers (CLSR)

MPLS Label:

FRAMEHeader

IP HeaderMPLSHeader

DATA

TTL (8)LABEL (20) Exp (3) S (1)


Labels based on:– Source router routing table– Source distinguishing (via Route

Distinguisher) – IP / Multicast Address– SLA/QoS Parameters

Put into Packet Label Stack Forwarding Equivalence Class CreationLabel Information Base (Labels and FEC bindings)• Distributed over Label Distribution Protocol


Generalized Multi-Protocol Label Switching (GMPLS) protocol suite (RFC 3471)

• extending the label switching from

packet/cell/frame-switched technologies to

connection-oriented technologiesTransport Layer:• Physical sublayer (Fibres, Optical Muxes,

wavelengths, )• Logical sublayer - Logical connections

Source to Destination Mode, constitued by LSR


GMPLS encompasses:

• Packet-switching-capable devices (IP/MPLS routers and layer-2 devices (ATM, FR, Ethernet)),

• Time division multiplexing-capable devices (SDH) Reconfigurable Add/Drop Multiplexers (RADMs)

and Digital Cross-Connects (DXC),• Lambda (or wavelength) switching-capable devices

(Reconfigurable Optical ADMs (ROADMs) and Optical Cross-Connects (OXCs),

• Waveband-switching-capable devices (WaveBand Cross-Connects, WBXC),

• Fiber switching-capable devices (Fiber XC, FXC).


DTM - DYNAMIC CIRCUIT SWITCHINGLine capacity shared into the frames 125 usSlot 64 bits, 512 kb/sChannel - n x slot, n x 512 kb/sDynamic Bandwidth allocation n x 512 kb/s

125usFrame

CONTROL

ChannelA

ChannelB

Link Capacity

Slots

Frames

DTM over SDH

DTM over WDM

Questions?


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