metropolitan area network evolution author:jipson paul kolenchery supervisor:prof.raimo kantola...
TRANSCRIPT
Metropolitan Area Network Evolution
Author:Jipson Paul Kolenchery
Supervisor:Prof.Raimo Kantola
Instructor:Timo-Pekka Heikkinen
Outline
• Introduction• Drive for Ethernet in metro networks• MAN evolution• Evolution of Ethernet to Carrier Grade Ethernet• Metro Ethernet Forum• Metro Ethernet Deployment models• Analysis of Packet carrier transport technologies• Scenario analysis• Conclusion
Introduction
• MAN-Metropolitan Area Network• MAN implementation options• Traffic pattern in MAN• Packet carrier transport in MAN
– Ethernet in MAN
• Options for Ethernet transport– Native Ethernet based PBB-TE– MPLS-TP– SDH based Metro Ethernet
Drive for Ethernet in metro networks• Traditional MAN deployments
– TDM based – Best suited for voice
• TDM interfaces– Bandwidth grows in step function– BW scaling requires provisioning at CPE and Central
office which increases OPEX
• Ethernet interfaces– Fine grained granularity in bandwidth scaling– Bandwidth scaling requires less OPEX
MAN evolution
• MAN evolution– From TDM based implementation to carrier
grade packet transport
• Evolution depends on– Type of service provider– Geographical area– Regulations
Evolution of Ethernet to Carrier Grade Ethernet (1)• Ethernet
– Medium Access Control standard – Invented by Robert M. Metcalfe– IEEE 802.3
• Evolution to carrier grade Ethernet– Ethernet VLAN (IEEE 802.1Q)– Provider Bridge (IEEE 802.1ad)– Provider Backbone Bridge (IEEE 802.1ah-2008)– Provider Back Bone Bridge with Traffic Engineering
(IEEE 802.1Qay)
Evolution of Ethernet to Carrier Grade Ethernet(2)• Ethernet VLAN (802.1 Q)
– 32 bit VLAN tags which contain 12 bit VLAN ID
FCS DataType/ Length
Source addressDestination address
TagFCS DataType/ Length
Source addressDestination address
TCI- Tag Control Identifier
TPID- Tag Protocol Identifier
VLAN ID 802.1p TPID- Tag Protocol IdentifierCFI
32 bit
16 bit 16 bit
12 bit 1 bit 3 bit 16 bit
Ethernet frame without VLAN Tag
Ethernet frame with 32 bit VLAN Tag (802.1Q)
Evolution of Ethernet to Carrier Grade Ethernet(3)• Provider Bridge (IEEE 802.1ad)
– Two VLAN tags and hence called Q-in-Q
FCS DataType/ Length
Source addressDestination address
TagFCS DataType/ Length
Source addressDestination address
Ethernet frame without VLAN Tag
Ethernet frame with 32 bit VLAN Tag (802.1Q)
Ethernet frame with 32 bit VLAN Tag (802.1ad)
C-TagFCS DataType/ Length
Source addressDestination address
S-Tag
Evolution of Ethernet to Carrier Grade Ethernet(4)• Provider Bridge back bone(IEEE 802.1ah-2008)
– A new header for service provider network– True traffic separation
VLANTag
FCS DataType/ Length
Source addressDestination address
32 bit
Backbone Ethernet Frame
B-TagB-FCSCustomer Ethernet Frame
Type/ Length
B-Source address
B-Destination address
I-Tag
48 bit48 bit32 bit32 bit32 bit 64-1492 Bytes 16 bit
Customer Ethernet Frame
32 bit 64-1492 Bytes 16 bit 48 bit 48 bit
Evolution of Ethernet to Carrier Grade Ethernet(5)• Provider Bridge Backbone with Traffic Engineering (PBB-
TE) IEEE 802.1ag• PBB + TE• Uses pre-established connection oriented path• Uses faster protection switching
– Two redundant paths per every virtual connection– 802.1ag Connectivity Fault Management messages for
performing OAM• Features
– No loops in the path– No Spanning Tree Protocol (STP)– No dynamic forwarding tables– No flooding
Example of Provider Bridge Backbone with Traffic Engineering (PBB-TE) IEEE 802.1ag
Provider edge bridge
Provider backbone bridge
Customer Asite 1 Customer A
site 2
Service provider network
Primary active path
Protection path
Metro Ethernet Forum
• Formed in 2001• A global consortium of industries
– Promote interoperability and world wide deployment of Carrier Ethernet networks and services
• Defined 5 attributes for Carrier Ethernet– Standardised Services– Scalability– Reliability– QoS– Service Management
Metro Ethernet deployment models(1)• Virtual connections
– Point-to-point EVC – Multipoint-to-multipoint EVC
• Deployment models– Native Ethernet based (PBB-TE)– SDH based– MPLS based (MPLS-TP)
Metro Ethernet deployment models(2)• Point-to-point EVC
Metro Ethernet Network
UNIUNI
Point-to-Point EVC
UNI
Metro Ethernet deployment models(3)• Multipoint-to-multipoint EVC
Metro Ethernet Network
UNI
UNI
UNI
UNI
Multipoint-to-multipoint EVC
Metro Ethernet deployment models(4)
Native Ethernet based-PBB-TE
Customer LAN site 1
Customer LAN site 3
Customer LAN site 2
Customer LAN site 4
Service provider PBB-TE network
Client Ethernet frame
PBB Ethernet frame
Client Ethernet frame
Customer LAN site 1
Customer LAN site 3
Customer LAN site 2
Customer LAN site 4
Service provider PBB-TE network
Client Ethernet frame
PBB Ethernet frame
Client Ethernet frame
Metro Ethernet deployment models(5)
SDH based
ADM
ADM
ADM ADMSDH Core MAN Network
Carrier Class Ethernet Switch
ADM
ADM
ADM ADMSDH Core MAN Network
Carrier Class Ethernet Switch
Metro Ethernet deployment models(6)
MPLS based
• IP/MPLS is not carrier grade
• Layer-2 MPLS to provide VPN and VPLS service
• MPLS-TP – A carrier grade layer-2 MPLS standard– Jointly developed by ITU-T and IETF – Separate OAM and MPLS forwarding
VPLS using layer-2 MPLS
VPN1
VPN2
VPN3
Customer A,
Site 1
Customer A,
Site 2
Customer B,
Site 3
Customer B,
Site 1
Customer B,
Site 2
Customer A,
Site3
Customer A,
Site 4
VFI for VPN1 VFI for VPN3
Layer-2 Virtual Circuits
Layer-2 LSP
PE1
PE2 PE3
PE4
MPLS backbone
Analysis of Packet carrier transport technologies (1)• Four metrics to compare PBB-TE and
MPLS-TP1. Performance
– MPLS-TP for voluminous traffic – PBB-TE for medium and low traffic
2. Scalability– MPLS-TP is more scalable for voluminous
traffic – PBB-TE for low and medium loads
Analysis of Packet carrier transport technologies(2)3. Reliability
– MPLS-TP • Offers linear protection mechanism• Unidirectional and bidirectional switching• Non revertive operation and revertive operation
– PBB-TE• TE capability of protocol• Protection switching triggered using CFM• Non revertive operation and revertive operation• Load sharing possible
• Both PBB-TE and MPLS-TP offer carrier grade transport with less than 50 ms protection switching interval
Analysis of Packet carrier transport technologies(3)4. Complexity and manageability
– PBB-TE interoperable with installed Ethernet bridges; provisioning needed only at PE
– MPLS-TP is compatible with IP/MPLS; provisioning needed only at PE
– Both PBB-TE and MPLS TP offer strict operator control and efficient OAM
– Low CAPEX for PBB-TE as it is based on native Ethernet standard
– Less skilled labour needed for PBB-TE– Network peering possible in PBB-TE using NNI
while peering is rarely seen in MPLS-TP
Scenario Analysis
Choice of transport network technology
Scenario Analysis
• To propose an appropriate transport technology for meeting the present and future needs of a service provider
• Based on Paul J.H Schoemaker’s method• Three scenarios
– Incumbent MAN service provider– A green field MAN service provider– A MAN service provider selling transport
service to a mobile network
Procedure for Scenario Analysis
• Scenario Planning• Identify scope and time frame of the
scenario• Identify major stakeholders • Identify basic trends• Identify uncertainties• Develop scenario themes• Propose implementation scenarios
Scenario Planning
• Helps to imagine how future would unfold minimising under prediction and over prediction
• Divide our knowledge into two areas: things we know something about (trends ) and elements we are not certain about (uncertainties)
• Simplify the possible outcomes of uncertainties• Identify themes from outcomes of uncertainties
and trends– Literature, survey, simulation results, brainstorming,
and interviews of major stakeholders to propose decision scenarios
Scope and time frame of the scenario• Time frame of this scenario planning is 5 years• Change of traffic pattern
– more voice – less data to more data and less voice• Internet users increasing by 16%• The power consumption of the network elements
worldwide increasing by 12%• Arrival of mobile broadband, increase in data
traffic and QoS requirements• Service providers are searching for a better
technology to meet the needs with less Capex and Opex
The major stakeholders of this scenario1. Subscribers or customers of various
operators
2. Access network operators (Fixed and mobile)
3. Transport network service providers
4. Vendors
Basic trends that effect MAN evolution
• Customer traffic is increasing• The global mobile traffic is expected to increase 26-fold between
2010 and 2015• Most voice services will be replaced by VOIP• VOIP applications needs greater QoS• Fine grained and more dynamic BW scaling needed• Delay in backhaul is a serious concern• Improved OAM mechanism in their network that can isolate and
rectify faults quickly• Electric power and cooling needed for capacity expansion• Service providers are looking for a packet based transport• PBB-TE and MPLS-TP standards are available• 40 Gigabit Ethernet (40GbE) and 100 Gigabit Ethernet(100GbE) are
coming to market soon• Energy Efficient Ethernet (EEE)
Uncertainties in MAN evolution1. Will carrier packet transport networks
based on PBB-TE and MPLS-TP standards be soon adopted for transport in MAN?
2. Will there be lower power consumption for PBB-TE and MPLS-TP products?
3. Is there a need for heavier cooling arrangements for the products based on PBB-TE and MPLS-TP products?
4. Will the chip design technology reach the level to process data at 10Gigabit and 100 Gigabit speeds sooner?
5. Will the regulations for using packet based transport becomes more flexible in the near future, especially in America?
6. Is it easy to develop or find laborers with the skill set needed to run these technologies?
7. What is the significance of economies of scale in packet transport technologies?
1 2 3 4 5 6 7
1 X + - + + + +
2 X X - ? ? ? ?
3 X X X ? ? ? ?
4 X X X X ? ? ?
5 X X X X X ? +
6 X X X X X X ?
7 X X X X X X X
Correlation matrix of uncertainties in MAN
Scenario Themes
• Packet carrier transport is the ultimate solution• Two competing technologies are PBB-TE and
MPLS-TP and both of them have its significance• Choice depends on type of service provider and
type of operators supported by service providers• Three main themes are
– Incumbent service provider– Green field service provider– Service provider providing mobile backhaul
Scenario analysis and decision scenario for an incumbent MAN service provider
OAM network
Edge network
Metro network
Core network
Corporate network
Corporate network
DSL
2G/3G/BTS Network
Controller IP/MPLS network
IP/MPLS network
MPLS-TP PE
MPLS-TP PE
MPLS-TP PE
MPLS-TP PE LSR
LSR
LSR
LSR
IP MPLS-TP IP/MPLS
• Incumbent service provider uses IP/MPLS in its network
• MPLS-TP is compatible IP/MPLS
• Less CAPEX as provisioning is needs only at PE
• Easy to train existing IP/MPLS work force to MPLS-TP
• Choice is MPLS-TP
Scenario analysis and decision scenario for a green field MAN service provider
Customer LAN site 1
Customer LAN site 3
Customer LAN site 2
Customer LAN site 4
PBB edge bridges
PBB core bridges
Service provider PBB-TE network
Client Ethernet PBB Ethernet MPLS
2G/3G/BTS Network
Controller
Metro networkEdge network
MPLS network
MPLS network
Core network
OAM network
Customer LAN site 1Customer LAN site 1
Customer LAN site 3Customer LAN site 3
Customer LAN site 2Customer LAN site 2
Customer LAN site 4Customer LAN site 4
PBB edge bridges
PBB core bridges
Service provider PBB-TE network
Client Ethernet PBB Ethernet MPLS
2G/3G/BTS Network
Controller
Metro networkEdge network
MPLS network
MPLS network
Core network
OAM network • Green field service provider prefers a revolutionary technology at low cost
• PBB-TE needs less CAPEX as it is native Ethernet based
• Less OPEX as provisioning is needed only at PE
• Less skilled work force needed
• E-LAN and E-Line offers fine grained granularity
• Choice is PBB-TE
Scenario analysis and decision scenario for a service provider providing mobile backhaul
RNC
RNC
UNI
UNI
UNI
UNI
BS
E-NNI
PBB-TE CEN-A
PBB-TE CEN-B
MSS MGW SGSN MME/S-GW
PBB-TE CEN-C
E-NNI
VLAN-Trunk
VLAN-Trunk
VLAN-Trunk
VLAN-Trunk
eNB
GGSN
P-GW LTE CN
PS-CNCS-CN
RAN
RNC
RNC
UNI
UNI
UNI
UNI
BS
E-NNI
PBB-TE CEN-A
PBB-TE CEN-B
MSS MGW SGSN MME/S-GW
PBB-TE CEN-C
E-NNI
VLAN-Trunk
VLAN-Trunk
VLAN-Trunk
VLAN-Trunk
eNB
GGSN
P-GW LTE CN
PS-CNCS-CN
RAN
• Large amount of data with HSPA and LTE
• Dynamic nature of traffic in mobile network
• Dynamic and fine grained BW allocation needed
• PBB-TE is the best solution due to fast scaling EVCs, network peering capability of NNI,dynamic provisioning etc
Timing solution in packet carrier transport• Timing-over-packet
– Implemented with Precision Timing Protocol (PTP) IEEE 1588v2 protocol
– Independent of layer-2 and layer-3 networks
• Synchronous Ethernet– Operates in the physical
layer– Defined in ITU G.8261– needs to be supported in
all nodes along the chain between the switching office and the cell site
– link frequency is synchronised to a traceable primary reference clock and physical layer of Ethernet is used to synchronise all participating nodes to the same reference clock
BTS
BTS
RNC
PTP master
Packet network
Unicast timing packets
Network reference
External reference
Timing over packet
Reference models proposed by MEF for Ethernet based mobile backhaul
BTS
BTS RNC
Carrier Ethernet backhaul network RNC
UNI
UNI
UNI
UNI
BTS
BTS
RNC
RNC
UNI
UNI
UNI
UNI
GIWF
GIWF
GIWF
GIWF
CEN-A
CEN-A
CEN-A
CEN-A
E-NNI
E-NNI
E-NNI
Single Domain Reference Model
Multi Domain Reference Model
Use case models for single and dual Iub proposed by MEF (1)
BS
RNC
UNIUNI
GIWF
GIWF
Legacy Network
CEN
BS
RNC
UNIUNI
GIWF
GIWF
Legacy Network
CEN
BS
RNCUNIUNIGIWF GIWF
CENBS
RNCUNIUNIGIWF GIWF
CENCEN
Legacy Split access
Legacy Backhaul
Use case models for single and dual Iub proposed by MEF (2)
BS
RNC
UNIUNI
Legacy Network
CEN
BS
RNC
UNIUNI
Legacy Network
CEN
BS
RNCUNIUNI
CENBS
RNCUNIUNI
CENCEN
Split access
Full Ethernet
Conclusion
• PBB-TE and MPLS-TP give carrier grade features to Ethernet in MAN
• Usability depends on scenarios– Greenfield service provider>PBB-TE– Incumbent service provider>MPLS-TP– For mobile backhauling>PBB-TE
• PBB-TE is suitable for highly varying low and dynamic loads– Suitable for MAN
• MPLS-TP is suited for very high and less dynamic traffic– Suitable for core
Thank You