Architectural Options for Metro Carrier-Ethernet Network Buildout: Analysis & Evaluation

Metanoia, Inc.
Critical Systems Thinking™

Architectural Options for Metro
Carrier-Ethernet Network Buildout:
Analysis and Evaluation

Metanoia, Inc.
Email: experts@metanoia-inc.com
Web: http://www.metanoia-inc.com
Phone: +1-888-641-0082
© Copyright 2009 Fax: +1-888-641-0086
All Rights Reserved

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Workshop Outline
 Overview of Architectural Options

 Applicability of Key Technologies to Access/Metro/Core
 Q-in-Q (PB), MAC-in-MAC (PBB), 802.1Qay (PBB-TE) and PVT, IP/MPLS,
MPLS-TP

 Basic Architectures and Their Analysis
 Parallel
 Overlay
 Uniform
 Mobile-Backhaul

 Hybrid Architectures and Their Analysis
©Copyright 2009 Carrier Ethernet Technology Strategies & Evolving
All Rights Reserved Operator Best Practices M1-2

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Workshop Outline

MPLS-TP

 Parallel
 Overlay
 Uniform
 Mobile-Backhaul (presented in detail later)


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Building Carrier Ethernet Networks Critical Systems Thinking™

Architectural Choices
Carrier Ethernet Network Architectural Choices

Parallel Overlay Uniform Mobile
Networks Networks Networks Backhaul

IP/MPLS + Ethernet in
parallel, spanning same Ethernet only in
Ethernet over IP /MPLS Ethernet -based
geographic area access/metro/core
Ethernet à L2 services
IP/MPLS à L3 services IP/MPLS over Ethernet IP/MPLS only in
access/metro/core IP/MPLS-based

 Three basic options to architect a carrier Ethernet network
 Parallel, Overlay, Uniform

 Mobile Backhaul – specially designed for wireless data and mobile voice traffic
 Hybrids – numerous options, based on operator network status and technology
availability, discussed extensively later in this module

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Our Analysis Approach For Each Critical Systems Thinking™

Basic Architectural Option
 Network Architecture
 Overall architecture/layout of the network

 Logical Structure
 How the devices are logically connected at the service layer

 Physical Realization (of the logical structure)
 What constructs are used at the transport layer (not PHY transport,
rather the Carrier Ethernet transport) to realize the logical structure

 Protocol Stack
 How tunnelling/interworking occurs in different segments of the
network


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Workshop Outline

MPLS-TP

 Parallel
 Overlay
 Uniform


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Applicability of Key Technologies: Critical Systems Thinking™

Assessment of Suitability
 Reference is to different network segments within the metro
network itself
 Metro Access (referred to in this workshop as “access”)
 Metro Aggregation (referred to in this workshop as “metro”)
 Metro Core (referred to in this workshop as “core”)
 “Eyeball” assessment of which technology is suitable for which
particular segment
 Ratings Scale based on inherent properties of technology
    Optimally suited – excellent fit/match for segment
   Moderately suited – reasonable fit/match for segment
  Minimally suited – could be used, but would not be effective
  Not suited – Not recommended for this segment (either
incapable or overkill for the segment)


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Applicability of Key Technologies: Critical Systems Thinking™

A Comparative Rating
Metro Access Metro Aggregation Metro Core

Q-in-Q   
Connectionless

802.1ad (PB) Good with small # flows Scalability strained w/ Unscalable (due to SPT,
(few hundreds) large # flows (thousands) flooding, convergence)

MAC-in-MAC   
802.1ah (PBB) Suitable for access, but Unstable and unscalable
Ideally scaled for agg.
likely overkill (SPT/flooding, mgt.)
802.1 Qay   
(PBB-TE) and Waste, as config./mgt. Useable, gives TE and TE/ manageability help
PVT overhead not worth it manageability long-lived paths, QoS
Connection-

  
Oriented

IP/MPLS Mature tech., suitable, but Signaling, automatic CP Long indstry experience,
needs configuration simplify confi. significant best practices

T-MPLS/   
MPLS-TP Suitable, but config. Controllability, similarity Better manageability of
overhead significant to SDH/SONET, resilience aggregated traffic

The above assessment/rating is based on the inherent properties/capabilities of each technology
(and not its maturity, availability, and standardization status, which are examined in Module 3)

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Workshop Outline

MPLS-TP

 Parallel
 Overlay
 Uniform


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Parallel Networks: Network Architecture
 Two isolated networks (ships-in-the-night)
 Different fibers, lambdas, or SDH/SONET channels

 Separate systems (for Ethernet and IP/MPLS) or independent
cards in the same system

 IP/MPLS network can be:
 p2p, mp2mp

 Ethernet network can be PB, PBB, PBB-TE based, and be:
 p2p, mp2mp, p2mp


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Why Parallel Networks?
If majority of metro services are ...
 Ethernet
 IP/MPLS connections handled by backhauling them from
spoke(s) to metro hub, where IP routing is done
 IP routing capability not needed in spoke COs

 IP or IP/MPLS
 Mesh IP/MPLS routers by co-locating with Ethernet switches in
all or some CO/POPs


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Why Parallel Networks?
 Useful when the provider L2 (Ethernet) and L3 (IP/MPLS)
networks have
 Shared POPs/Cos
 MSPPs with both IP/MPLS and Ethernet capabilities

 Applicable for operators that wish for both technologies to
co-exist with service aggregation


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Parallel Networks: Network Layout
IP/MPLS
Co-located IP/MPLS Linecard
Router & Ethernet IP/MPLS
Switch

IP/MPLS Router IP/MPLS or T-MPLS
or MPLS-TP Network

Ethernet
Hybrid system with two
types of line cards

Ethernet Linecard

Ethernet Switch
PB, PBB, PBB-TE Network


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Parallel Networks: Logical Structure
IP/MPLS
Co-located IP/MPLS Linecard
Logical IP /MPLS
Router & Ethernet Link
Switch

IP/MPLS Router Logical IP /MPLS
Link

Hybrid system with two
types of line cards
Logical Ethernet Linecard
Ethernet Link

Ethernet Switch
Ethernet Switch

Logical
Ethernet Link


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Parallel Networks: Critical Systems Thinking™

IP/MPLS Network Realization
Bi-directional Logical Mesh
logical links IP/MPLS Layer
(a) Logical MPLS Network
L1 L2

L3

L4 L5

L3 mp2p LSPs

Physical links can have
Ethernet or SONET /SDH framing L2

(b) LSP Realization of
Logical Network L1 L5
p2p LSPs

L4


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Parallel Networks: Critical Systems Thinking™

Ethernet Network Realization
Logical Mesh at Logical links
Ethernet Layer (a) Logical Ethernet Network

(b) E-Line Realization of
Logical Network
E-Line

(Realization via
Ethernet entities)
Physical links with
Ethernet framing

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Parallel Networks: Protocol Stack
 In parallel networks, the protocol stack is trivial, since each
network is fully independent of the other
 For Ethernet it is:
Ethernet
Header Varies depending on whether the Ethernet
Payload network is PB, PBB, or PBB-TE-based

 For IP/MPLS it is:

LSP-Label
May vary if further nesting of LSPs is used
VC-Label

IP Header

Payload


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Parallel Networks: Assessment
Pros Cons
 Flexible  Higher CapEX relative to uniform
 IP/Ethernet networks/services can network
grow independently  Need 2x fibers, lambdas, or
 Fault isolation SDH/SONET channels
 Faults in one n/w, do not affect  More systems, cabling; thus,
service in the other CO/POP space & power
 Different mgt. s/w – one for each
 Service independence
network: IP, Ethernet
 L2 svcs. not affected by L3 svcs.
 Greater OpEX
and visa-versa
 More vendors, maintenance
 Greater number of s/w and mgt.
tools

 Good choice if a provider has either an Ethernet- or IP/MPLS-dominant network,
and wishes to expand into the other incrementally


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Overlay Networks: IP/MPLS over Ethernet
 Metro is built using Ethernet switches
 PB, or PBB, or PBB-TE capable

 Requires transport network
 SDH/SONET, lambda’s or fiber to interconnect switches

 Ethernet layer is transmission network
 Interconnects IP/MPLS routers – using p2p, mp2mp, p2mp constructs

 Ethernet network is oblivious to IP/MPLS layer

 IP/MPLS routers (U-PE, N-PE, PE) connected in logical mesh or
hub-and-spoke, or some mix of two


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Why Overlay Networks with Critical Systems Thinking™

IP/MPLS-over-Ethernet?
 Ethernet
 IP/MPLS connections handled by backhauling them from
spoke(s) to metro hub, where IP routing is done
 IP routing capability not needed in spoke COs

 IP or IP/MPLS
 Mesh IP/MPLS routers by co-locating with Ethernet switches in
all or some CO/POPs


Metanoia, Inc.
IP/MPLS-over-Ethernet Critical Systems Thinking™

Overlay Network: Network Layout

Co-Located
Systems IP/MPLS
Single IP/Ethernet
Platform
Ethernet

PB, PBB, or PBB-TE
Ethernet Network

CE

Customer Co-Located
Edge Device Systems
All Rights Reserved M1-21
CE Operator Best Practices

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Overlay Network: Logical Structure

Logical Links

Single IP/Ethernet
Platform

PB, PBB, or PBB-TE
Network

Logical Mesh


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Overlay Network: Realization via E-Line
p2p E-Line service
(offered by underlying
Ethernet network)

Single IP/Ethernet
Platform

 The “transmission network” here is the
Logical Links
Ethernet network
 Logical network is thus realized using
this network’s entities: E-lines


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Overlay Network: Realization via E-LAN

Single IP/Ethernet
Platform mp2mp Ethernet
(E-LAN)

 The “transmission network” here is the
Ethernet network
 Logical network is thus realized using
this network’s entities: E-LAN


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Overlay Network: Protocol Stack
CE

IP/MPLS Co-located
Systems IP/MPLS
Combined IP/
Ethernet Switch
IP Service IP Service
Ethernet
CE Ethernet Svc
CE
Ethernet Svc Ethernet Network

IP Service or PB/PBB PB/PBB PB/PBB
PBB-TE PBB-TE PBB-TE
IP/MPLS Service
MPLS MPLS MPLS MPLS MPLS
Ethernet Ethernet Ethernet Ethernet Ethernet Ethernet Ethernet
IP IP IP IP IP IP IP
Payload Payload Payload Payload Payload Payload Payload

PB/PBB PB/PBB PB/PBB
Ethernet Service PBB-TE PBB-TE PBB-TE
Ethernet Ethernet Ethernet Ethernet Ethernet
Payload Payload Payload Payload Payload


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Overlay Networks IP/MPLS-over Critical Systems Thinking™

-Ethernet: Assessment
Pros Cons
 Lower CapEX relative to Parallel n/wks  Lower flexibility relative to Parallel
 Potentially fewer systems (need only network
one set for underlying txn. network –  IP/MPLS & Ethernet networks coupled
here Ethernet)  Cannot grow independently
 Less fiber – due to common transport
 Resilience issues
 Simpler mgt – due to fewer systems,
and hybrid systems (IP+Ethernet)
 Faults in Ethernet network may affect
IP/MPLS service
 Lower OpEx
 Potentially, one vendor
 Single s/w and mgt. tools
 Single dept. to manage network

 Good choice if a provider has primarily an Ethernet infrastructure, and wishes to
expand into IP/MPLS services


Metanoia, Inc.

Overlay Networks: Ethernet-over-IP/MPLS
 Metro is built using IP/MPLS devices
 p2p, mp2mp IP/MPLS, MPLS-TP/T-MPLS network or any mix

 Requires one transport network
 SDH/SONET, lambda’s or fiber to interconnect IP/MPLS routers

 MPLS layer is transmission network
 Interconnects Ethernet switches – using p2p (VPWS) or mp2mp (VPLS) constructs

 VPWS interconnection à
 MPLS network provides a transparent tunnel (network interworking)

 VPLS interconnection à
 MPLS network participates in Ethernet switching via VSI (service interworking)

 Ethernet switches connected as logical mesh or hub-and-spoke or mesh-star
topology


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Why Overlay Networks with Critical Systems Thinking™

Ethernet-over-IP/MPLS?
 IP/MPLS
 Ethernet connections are backhauled to metro hub, where
Ethernet switching is done
 Ethernet switching capability not needed in spoke COs/PoPs

 Ethernet
 Mesh Ethernet switches by co-locating with IP/MPLS routers in
all or some CO/POPs


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Ethernet-over-IP/MPLS Critical Systems Thinking™

Overlay Network: Network Layout

Co-Located
Systems
Ethernet
Single IP/Ethernet
Platform IP/MPLS

IP/MPLS or T-MPLS
or MPLS-TP Network

IP SVC

Customer Edge Co-Located
CE
Device Systems
Ethernet
SVC

CE

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Overlay Network: Logical Structure

Logical Links

Single IP/Ethernet
Platform

IP/MPLS or T-MPLS
or MPLS-TP Network

Logical Mesh


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Overlay Network: Realization via VPWS
p2p PW in IP/MPLS
network

Logical Links

Single IP/Ethernet
Platform

Logical Mesh


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Overlay Network: Realization via VPLS

Single IP/Ethernet
PW full-mesh (VPLS) with
Platform VSI-based routing


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Overlay Network: Protocol Stack
CE
CE

IP Service Co-located
Systems Ethernet

Ethernet SVC IP/MPLS
IP Service
Ethernet
CE IP/MPLS Network CE
SVC

Ethernet SVC

MPLS MPLS MPLS
Ethernet Label Label Label
Service PWE3 PWE3 PWE3
Label Label Label
PB/PBB PB/PBB PB/PBB PB/PBB PB/PBB
PBB-TE PBB-TE PBB-TE PBB-TE PBB-TE
Ethernet Ethernet Ethernet Ethernet Ethernet Ethernet Ethernet

IP Service MPLS MPLS MPLS
Ethernet Label
Ethernet
Label Label
IP IP IP IP IP
Payload Payload Payload Payload Payload


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Ethernet-over-PB-over-IP/MPLS Critical Systems Thinking™

(VPWS) Interworking: Protocol Stack
CE
CE

Co-located
Systems Ethernet

Ethernet SVC
IP/MPLS
CE IP/MPLS, T-MPLS, CE
MPLS-TP Network

Ethernet SVC

One-to-one
Mapping (No
MAC Lookup) LSP Label (MPLS) LSP Label

VC Label (PWE3) VC Label

C-DA C-DA C-DA C-DA

C-DA C-SA C-SA C-SA C-SA C-DA

C-SA 5-tag 5-tag 5-tag 5-tag C-SA

C-tag C-tag C-tag C-tag C-tag C-tag

Payload Payload Payload Payload Payload Payload

Customer Ethernet Switch IP/MPLS
Packet Packet Router Packet

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Ethernet-over-PBB-over-IP/MPLS Critical Systems Thinking™

(VPWS) Interworking: Protocol Stack
CE
CE

Co-located
Systems Ethernet

Ethernet SVC
IP/MPLS
MPLS-TP Network

Ethernet SVC One-to-one
Mapping (no MAC
lookup) LSP Label (MPLS) LSP Label


B-DA B-DA B-DA B-DA

B-SA B-SA B-SA B-SA

B-tag B-tag B-tag B-tag

I-tag I-tag I-tag I-tag

C-DA C-DA C-DA C-DA

C-SA S-tag S-tag S-tag S-tag C-SA



©Copyright 2009
Packet Packet Carrier Ethernet Technology Strategies & Evolving
Router Packet

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Ethernet-over-PB-over-IP/MPLS Critical Systems Thinking™

(VPLS) Interworking: Protocol Stack
CE
CE

Co-located
Systems Ethernet

Ethernet SVC
IP/MPLS
MPLS-TP Network

Ethernet
Ethernet SVC bridging VPLS
(VSI MAC
Lookup)

LSP Label (MPLS) LSP Label


C-DA C-DA C-DA C-DA

VPLS
C-SA 5-tag VSI 5-tag 5-tag 5-tag C-SA



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Ethernet-over-PBB-over-IP/MPLS Critical Systems Thinking™

(VPLS) Interworking: Protocol Stack
CE
CE

Co-located
Systems Ethernet

Ethernet SVC
IP/MPLS
MPLS-TP Network
Ethernet
Ethernet SVC bridging VPLS
(VSI MAC
LSP Label (MPLS) LSP Label
Lookup)

B-DA B-DA B-DA B-DA

B-SA B-SA B-SA B-SA

B-tag B-tag B-tag B-tag

I-tag VPLS I-tag I-tag I-tag

C-DA VSI C-DA C-DA C-DA
C-DA C-DA
C-SA C-SA C-SA C-SA
C-SA S-tag S-tag S-tag S-tag C-SA




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Uniform Networks: Network Architecture
 One technology used throughout (for all three metro segments)
 Access, Aggregation, and Core

 Technology could be either Ethernet or IP/MPLS

 Ethernet-only option
 Access can be 802.1ad (Q-in-Q)
 Metro can be 802.1ah (MAC-in-MAC)
 Core can be 802.1Qay (Provider Backbone Bridging – TE)

 IP/MPLS-only option
 Access uses p2p PWs in hub-and-spoke design
 Metro uses a meshed VPLS design
 Core uses a hierarchically meshed H-VPLS design


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Uniform Networks: Ethernet-Only
 Comprised typically of access, metro, core segments
 Access à PB (802.1ad), metro à PBB (802.1ah), core à PBB/PBB-TE
(802.1Qay)

 Service-Layer is Ethernet, with remote CE’s knowing each other’s MAC address
 Devices at service-layer connected by p2p or p2mp Ethernet tunnels

 Physical Realization (of logical structure)
 Transport layer could be Ethernet or SDH/SONET

 Protocol Stack
 Illustrated ahead ...


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Uniform Networks: Ethernet Only Critical Systems Thinking™

Network Layout and Protocol Stack
Access Network Aggregation Network Core Network Aggregation Network Access Network
(802.1ad) (802.1ah) (802.1Qay) (802.1ah) (802.1ad)
Provider Backbone Provider Backbone Provider Bridging (PBB)
Provider Bridging (PBB) BCB
Bridging (PBB) Bridging (PBB)
Last Mile
Last Mile IB-BEB BCB B-BEB B-BEB B-BEB IB-BEB PE CE
CE PE

PB B-BEB BCB
PBB – Traffic
Engineered (PBB-TE)
PB
CE
PE PE CE
IB-BEB
IB-BEB BCB B-BEB B-BEB B-BEB
802.1ad/Q-in-Q 802.1ah 802.1ah 802.1ad/Q-in-Q
encapsulation BCB
encapsulation decapsulation decapsulation
B-DA B-DA - Pinned paths B-DA
- Based only on
B-SA B-SA B-DA, B-SA, B-Tag B-SA
- No STP
B-Tag B-Tag B-Tag
- No MAC learning
I-Tag I-Tag I-Tag
Switching based on pre -
C-DA C-DA C-DA configured fwding tables C-DA C-DA

C-DA C-SA C-SA C-SA C-SA C-SA C-DA

C-SA S-Tag S-Tag S-Tag S-Tag S-Tag C-SA

C-Tag C-Tag C-Tag C-Tag C-Tag C-Tag C-Tag



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Uniform Networks: IP/MPLS-Only
 Comprised typically of access, aggregation (metro), core segments
 Two options exist:
 Option 1: Access/Metro (Aggregation) à p2p spoke PWs to backbone (core)
PEs, Core à H-VPLS mesh between backbone PEs
 Option 2: Access à p2p spoke PWs to aggregation PEs, Metro
(Aggregation)/Core à H-VPLS mesh between all aggregation PEs

 Service-Layer is still Ethernet; remote CE’s/nPE’s learn MAC addresses
 Devices at service-layer connected by p2p MPLS LSPs

 Physical Realization (of logical structure)
 Construct used at transport layer are IP/MPLS p2p PWs in p2p LSPs

 Protocol Stacks
 Illustrated ahead ...

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Uniform Networks: IP/MPLS Only Critical Systems Thinking™

Network Layout and Protocol Stack (1)
(p2p PW) (p2p PW) (PW full mesh, H-VPLS) (p2p PW) (p2p PW)

Access + Aggregation spanned by spoke PWs Full PW Mesh
P per service
Spoke PW PE P nPE nPE P PE CE
uPE
CE uPE
P
P P

PE
CE uPE uPE CE
PE
PE P nPE P
nPE
VPWS (p2p) PW Spoke PW VPWS (p2p PW)
VPLS P VPLS decapsulation
encapsulation
encapsulation decapsulation

LSP LSP Tunnel LSP LSP LSP
Label Label Label Tunnel Label Tunnel Label
Spoke
PW Label PW Label PW Label Mesh PW Label Spoke PW Label
(PW) (VPLS (PW)
C-DA C-DA C-DA C-DA Instance) C-DA C-DA C-DA
C-SA C-SA C-SA C-SA C-SA C-SA C-SA
S/C-Tag S/C-Tag S/C-Tag S/C-Tag S/C-Tag S/C-Tag S/C-Tag


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Uniform Networks: IP/MPLS Only Critical Systems Thinking™

Network Layout and Protocol Stack (2)
(p2p PW) (PW full mesh) (PW full mesh, H-VPLS) (PW full mesh) (p2p PW)
Aggregation and Core spanned by Full PW Mesh
P
PW Full Mesh
Spoke PW nPE P PE PE P nPE CE
uPE
CE uPE
P
P P

PE
CE uPE Spoke uPE CE
nPE PW
nPE P PE P
PE
VPWS (p2p) PW VPLS VPLS
P VPWS (p2p PW)
encapsulation encapsulation decapsulation
decapsulation

LSP LSP LSP Tunnel LSP LSP Tunnel
Label Tunnel Label Label Label Label
Spoke
PW Label Spoke PW Label PW Label Mesh PW Label PW Label
(PW) (PW)
(VPLS
C-DA C-DA C-DA C-DA Instance ) C-DA C-DA C-DA


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Uniform Networks: IP/MPLS-Only Critical Systems Thinking™

Observations
 Trade-offs exist between Option 1 and Option 2 in terms of MAC
learning and PW scalability

 Option 1: PW full mesh in core, spoke PWs upto core nPEs
 nPEs must learn all customer MAC addresses
 PW mesh confined to core, thus only core PEs must be meshed
 Requires one PW mesh per customer’s service instance

 Option 2: PW full mesh in agg. + core, spoke PWs upto agg. nPEs
 nPEs learn all customer MACs, but fewer than in Option 1
 PW mesh, however, is between nPEs in all aggregation networks (thus
much larger with more PWs than in Option 1)
 Requires one PW mesh per customer’s service instance


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Workshop Outline

MPLS-TP

 Overlay
 Parallel
 Uniform


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Our Analysis Approach For Critical Systems Thinking™

Hybrid Architectures
 Network Overview
 Overall architecture/layout of the network

 Protocol Stack
 Explain tunneling/interworking in different network segments

 Assessment
 Key observations about the architecture
 Benefits and drawbacks of approach


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Hybrid Architectures: Overview
 Involve a combination of IP/MPLS and Ethernet (PB, PBB, PBB-TE)

 Access network, customer-edge to provider-edge, is common and
typically one of three Ethernet types (so not shown in figures)
 Vanilla Ethernet (802.1d)
 V-LAN capable Ethernet (802.1q)
 S-VLAN capable Ethernet or Q-in-Q (802.1ad)

 Two principal hybrid architectures
 H-VPLS with PB or PBB Aggregation
 H-VPLS with MPLS Aggregation


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Hybrid Architectures Taxonomy
H-VPLS with PB/PBB Aggregation

H-VPLS w/ Homogeneous H-VPLS with Heterogeneous
PBB Aggregation PB/PBB Aggregation

Type I Svc. Interface Type II Svc. Interface Modified PB PE Modified PBB PE
(S-Tag (B-VID) as delimiter) (I-SID as delimiter)

H-VPLS with MPLS Aggregation

PBB-capable uPE PBB-capable nPE PBB Migration
(PBB uPE, for short) (PBB nPE , for short)

PB service frames PBB service frames PB and PBB service
over H-VPLS core over H-VPLS core frames over H-VPLS core


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H-VPLS with PBB Aggregation: Critical Systems Thinking™

Type I Interface -- Overview
 Type I i/f is a B-tagged i/f with B-VID as service delimiter

 Handoff between BCB and N-PE is B-tagged PBB frame

 N-PE itself can be transparent to the frames
 Treats them as 802.1ad frames
 Only need support 802.1ad-style frames


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Type I i/f – Operation & Protocol Stack
PBB

Ethernet MPLS/PW Ethernet

CE U-PE BCB N-PE Raw or Tagged- N-PE BCB U-PE
mode Ethernet PW CE

PBB
X IP/MPLS
X
PBB
A1 IB-BEB C1 D1 IB-BEB B1

S-Tag I/f S-Tag I/f
(B-VID is Svc. delimiter ) (B-VID is Svc. delimiter )
All 3 operational modes
Supports VPLS for B-Tag supported:
(need not be PBB-aware) - Port Mode
- VLAN Mode
- VLAN Bundling Mode

LSP-Label

VC-Label

B-DA B-DA B-DA B-DA B-DA

B-SA B-SA B-SA B-SA B-SA

B-Tag B-Tag B-Tag B-Tag B-Tag

I-Tag I-Tag I-Tag I-Tag I-Tag

C-DA C-DA C-DA C-DA C-DA C-DA C-DA




Metanoia, Inc.
H-VPLS with PBB Aggregation Critical Systems Thinking™

Type I Interface: Assessment
 Application of the overlay model
 Use case: SP has converged to an MPLS core, but prefers Ethernet aggregation
to connect 802.1ad-based access networks
 A “steady-state” model, once all aggregation networks are 802.1ah-capable

Benefits Drawbacks
 No new functionality in VPLS PE  Needs extra replication in core
 Reduces C-MAC learning and PW (relative to w/o I-SID bundling)
mesh in core PEs  Unknown unicast, brdcast, or
 Due to I-SID bundling, multiple mcast in a single svc. instance (I-
svc. instances map to one bridge SID) leads to full brdcast in core
domain (B-VID)  May be addressed by per-I-SID
 Separates service layer (I-SID) flood containment
from network layer (B-VID)

Metanoia, Inc.

Type II Interface -- Overview
 Type II i/f: I-tagged i/f with I-SID as service delimiter

 B-Tag is locally significant in PBB cloud, not sent over core

 PE must support B-BEB and VPLS functionality
 Must interpret I-Tag


Metanoia, Inc.

Type II i/f – Operation & Protocol Stack
PBB PBB PBB


CE U-PE B-BEB N-PE N-PE B-BEB U-PE
CE

PBB
X IP/MPLS
X PBB
B-BEB D1 PBB
A1 C1 B-BEB B1

I-tag I/f I-tag I/f (Type II)
(Type II) (I-SID is svc. delimiter)
B-VID locally significant in 2 Mapping options
PBB, not xported over core -- I-SID à VPLS
Must support B-BEB
and VPLS capability -- I-SID àB-VID à VPLS

Internal B-VID,
B-BEB removes enables I-SID LSP-Label
PBB-specific bundling
B-Tag VD-Label

B-DA B-DA B-DA

B-SA B-DA B-SA B-DA B-SA

B-Tag B-SA B-Tag B-SA B-Tag







Metanoia, Inc.
H-VPLS with PBB Aggregation Critical Systems Thinking™

Type II Interface: Assessment
 Application of the overlay model
 Use case: SP has converged to MPLS core, but prefers Ethernet aggregation to
connect 802.1ad-based access networks
 Good for customers with mcast traffic (w/o mcast pruning fn. at VPLE-PE)

Benefits Drawbacks
 Less replication in core, w/o needing  N-PE complex with new capability –
per-I-SID flood containment needs B-comp for I-SID processing

 Supports tightly & loosely-coupled  Potentially larger # of PWs in core, for
service domains same # of services (relative to Type I)
 Increased segregation of svc.
instances (by I-SID) over disjoint PW
meshes


Metanoia, Inc.
H-VPLS with Heterogeneous Access Critical Systems Thinking™

Modified PB PE -- Overview
 Used to interoperate existing 802.1ad (PB) networks with
new 802.1ah (PBB) aggregation networks

 Both networks connect to an H-VPLS core/backbone

 PE interfacing with PB network must support VPLS and IB-
BEB functionality
 Mapping of S-VID to I-SID
 I-SID bundling into B-VID and mapping to a VPLS instance


Metanoia, Inc.
H-VPLS with Modified PB PE Critical Systems Thinking™

Operation & Protocol Stack
Q-in-Q PBB


CE U-PE1 BCB N-PE1 N-PE2 B-BEB U-PE2
CE

Q-in-Q
X IP/MPLS X
PBB
A1 C1 D1 B1

S-tag I/f I-tag I/f
(Type 1) (Type II)
Must support Must support
IB-BEB and B-BEB and
-- Participates in local I -SID VPLS VPLS
domain of MPLS core
-- Supports I-SID bundling
-- 1:1 mapping of S-VID à I-SID LSP-Label

VC-Label

B-DA B-DA

B-SA B-DA B-SA

B-Tag B-SA B-Tag

I-Tag I-Tag I-Tag

C-DA C-DA C-DA C-DA C-DA



S/C-Tag C-Tag C-Tag S/C-Tag C/S-Tag S/C-Tag S/C-Tag


Metanoia, Inc.

H-VPLS with Modified PB PE: Assessment
 Overlay with cascade of IP/MPLS and Ethernet networks
 Use case: SP has converged to MPLS core, but has different Ethernet
aggregation/access networks, which have not converged to a single Ethernet
technology

Benefits Drawbacks
 Reduces PW mesh in core  N-PE is complex with new
 Via I-SID bundling, where group of capability – needs IB-BEB
I-SIDs is mapped to B-VID and to a functionality
VPLS instance

 PB PE (N-PE1) needs to learn
 Supports tightly, loosely-coupled, many C-MAC addresses
and different service domains


Metanoia, Inc.
H-VPLS with Heterogeneous Access Critical Systems Thinking™

Modified PBB PE -- Overview
 Used to interoperate existing 802.1ad (PB) networks with
new 802.1ah (PBB) aggregation networks

 Both networks connect to an H-VPLS core/backbone

 PE interfacing with PBB network must support VPLS and IB-
BEB functionality
 B-component faces PBB cloud
 I-component faces MPLS core, connects to VPLS forwarder


Metanoia, Inc.
H-VPLS with Modified PBB PE Critical Systems Thinking™

Operation & Protocol Stack
Q-in-Q PBB
I-Comp

B-Comp
CE U-PE1 PCB N-PE1 N-PE2 B-BEB U-PE2
CE

Q-in-Q
X IP/MPLS
X
PBB
1P 1P 1P 1P

S-tag I/f I-tag I/f
(Type I) (Type II)
Must support Must support
VPLS for B-tag IB-BEB
-- 1:1 mapping of S-VID (not PBB aware) and VPLS
to VPLS instance
-- S-VID bundle has no
counterpart in PBB n/w

B-DA

B-DA B-SA

LSP-Label B-SA B-Tag

VD-Label I-Tag I-Tag







Metanoia, Inc.
H-VPLS with Modified PBB PE: Critical Systems Thinking™

Assessment
 Overlay with cascade of Ethernet and IP/MPLS networks
 Use case: SP has converged to MPLS core, but has different Ethernet
aggregation/access networks, which have not converged to a single Ethernet
technology

Benefits Drawbacks
 VPLS core can operate without any  N-PE2 needs IB-BEB functionality
modifications
 Maps tags (I-tag) to VPLS instance  PB PE (N-PE1) must learn C-MAC
addresses
 Supports tightly, loosely-coupled, and
different service domains  Absence of S-VID bundling, implies
each I-SID maps to independent PW

mesh in core à no scaling in PWs
Viable option to incrementally at PBB
aggregation networks to existing PB
networks over IP/MPLS core  Need same I-SID domain across all
PBB aggregation networks for
consistent C-VID grouping


Metanoia, Inc.
H-VPLS with MPLS Aggregation Critical Systems Thinking™

PBB uPE -- Overview
 Used to integrate 802.1ah (PBB) functionality into an IP/MPLS
provider network

 PBB functionality is embedded in uPE to restrict MAC learning as
close to customer as possible

 PE at the IP/MPLS core is unchanged, and only needs IP/MPLS and
PW capability

 Bridging over VPLS network need be only 802.1ad capable as
 MAC forwarding is based on B-MAC address space
 Service delimiter is based on B-VLAN ID or B-VID


Metanoia, Inc.

PBB uPE: Operation & Protocol Stack
PBB

MPLS/PW MPLS/PW MPLS/PW

CE U-PE LSR N-PE N-PE LSR U-PE CE

MPLS
X IP/MPLS
X
IB-BEB MPLS
A1 C1 D1 IB-BEB B1
MPLS MPLS
I/f I/f
Spoke PWs per
Full PW mesh per VPLS instance -- Port Mode
-- VLAN Mode
Must support IB-BEB and Must support MPLS/PW VPLS instance
-- VLAN-bundling Mode
MPLS/PW encap of C-MAC Operates on B-DA, B-SA,
Maps svcs. to I-SID
frames into B- MAC frames B-VID only (not I-SID), so
I-SID àB-Tag (bridge domain)
need be 802.1ad capable
B-Tag à VPLS instance

LSP-Label LSP-Label LSP-Label LSP-Label LSP-Label

VC-Label VC-Label VC-Label VC-Label VC-Label

B-DA B-DA B-DA B-DA B-DA

B-SA B-SA B-SA B-SA B-SA

B-Tag B-Tag B-Tag B-Tag B-Tag







Metanoia, Inc.

PBB uPE: Assessment
 Overlay with IP/MPLS transmission n/w and Ethernet service
 Use case: SP converged to MPLS in core and aggregation networks
 I-SID allocation
 Global across MPLS networksno I-SID translation needed
 I-SID bundling must be consistent across all participating PEs

Benefits Drawbacks
 PBB functionality at uPE improves  Customer broadcast/mcast frames
scalability must be sent over entire B-VLAN

 Multiple I-SIDs per B-VLAN à fewer  Greater replication over VPLS PW
core PWs mesh
 As B-VLAN mesh is larger than scope
of any particular I-SID
 N-PE only learns uPE MACs à MAC
addresses scale


Metanoia, Inc.

PBB nPE -- Overview
 Used to integrate 802.1ah (PBB) functionality into an
IP/MPLS provider network

 PBB function embedded in nPE, when uPE is not capable

 Bridging over VPLS n/w must be 802.1ah capable, as nPE
 Assigns an I-SID for each service of a customer
 Muxes I-SIDs into a common bridge domain, or B-VLAN
 Maps either I-SIDs or B-VLANs to VPLS instances


Metanoia, Inc.

PBB nPE: Operation & Protocol Stack
Q-in-Q PBB Q-in-Q


CE U-PE LSR N-PE N-PE LSR U-PE
CE
IB-BEB
MPLS
X IP/MPLS
X
MPLS
A1 C1 IB-BEB D1 B1
MPLS MPLS
I/f I/f
Full PW mesh per PWs per customer
Must support customer or cust. grp (one service per PW,
VPLS and PBB no service muxing)
Supports
-- Port Mode
LSP-Label -- VLAN Mode
-- VLAN-bundling Mode
VD-Label

B-DA

B-SA

LSP-Label LSP-Label B-Tag LSP-Label LSP-Label
C-DA C-DA
VD-Label VD-Label I-Tag VD-Label VD-Label




C-Tag C-Tag C-Tag S/C-Tag C-Tag C-Tag C-Tag



Metanoia, Inc.

PBB nPE: Assessment
 Overlay with IP/MPLS txn network and Ethernet service
 Use case: SP has converged to MPLS in core and aggregation n/ws, but
aggregation n/w is not PBB capable
 Needs integration of PBB functionality into H-VPLS PE

Benefits Drawbacks
 PBB functionality at nPE  Spoke PWs terminate at nPE
improves VPLS PW scalability  nPE must learn all customer MAC
addresses

 nPE maps multipe I-SIDs into a B-
VLAN à fewer core PW meshes  Per-service spoke PWs à needs
significantly more spoke PWs
 Since uPE is not PBB aware


Metanoia, Inc.

H-VPLS with PBB Migration
 Provides migration path for operators with investments in IP/MPLS
(and VPLS) deployments

 Enables incremental induction of PBB into the network

 Expands scalability benefits of PBB over time with deployment

 Three migration scenarios:
 Non-PBB (802.1ad) encapsulated frames over VPLS core
 PBB-encapsulated (802.1ah) frames over VPLS core
 Mixed frames (802.1ad and 802.1ah) over VPLS core
 Depends on capabilities of different edge devices in network


Metanoia, Inc.
H-VPLS with PBB Migration: 802.1ad Critical Systems Thinking™

Frames in Core -- Overview
 Existing 802.1ad access/aggregation n/wks
 Unchanged – need no modifications
 nPE’s require no changes, and need no knowledge of PBB

 New MPLS-based access/aggregation networks with PBB
functionality on uPE
 Need IB-BEB functionality on nPE
 Required to terminate PBB encap. on incoming frames

 Ethernet frames in VPLS/H-VPLS core use 802.1ad format
 VPLS core operation is unchanged


Metanoia, Inc.
H-VPLS w/ PBB Migration 802.1ad Critical Systems Thinking™

Frames in Core: Operation & Protocols
Q-in-Q PBB
I-Comp I-Comp

B-Comp B-Comp
CE U-PE1 LSR N-PE1 N-PE2 LSR U-PE2
CE

MPLS
X IP/MPLS
X
IB-BEB D1 MPLS
A1 C1 MPLS IB-BEB B1
MPLS
I/f I/f

Must support Must terminate PBB PWs could be per
Must terminate
Spoke PWs per customer VPLS and MPLS/PW VPLS instance or per
PBB and
(one service per PW) service
MPLS/PW

LSP-Label LSP-Label
C-DA
VC-Label VC-Label

B-DA B-DA

B-SA B-SA

LSP-Label LSP-Label LSP-Label B-Tag B-Tag
C-DA
VC-Label VC-Label VC-Label I-Tag I-Tag




C-Tag C-Tag C-Tag S/C-Tag C-Tag C-Tag C-Tag



Metanoia, Inc.
H-VPLS with PBB Migration: 802.1ad Critical Systems Thinking™

Frames in Core: Assessment
 Use Case: SP has converged to MPLS in core and aggregation n/ws, but all
access/aggregation networks are not PBB capable
 Ideal when SP has single PBB-capable aggregation/access network

Benefits Drawbacks
 Requires no change to existing  nPE1 must learn all customer
access/aggregation n/wk (Q-in-Q) MAC addresses (as spoke PWs
terminate at nPE1)
 PBB benefit cannot be leveraged
 No change to existing VPLS nPEs
(those not facing 802.1ah n/wks)
 nPEs need full mesh of PWs


Metanoia, Inc.
H-VPLS with PBB Migration: 802.1ah Critical Systems Thinking™

 Existing 802.1ad access/aggregation n/wks
 Unchanged – need no modifications

 nPE’s must be upgraded for PBB-based processing (IB-BEB)
 All Ethernet svc frames over VPLS core are PBB-encapsulated

 New MPLS-based access/aggregation networks have PBB
functionality on uPE
 Need IB-BEB functionality on remote nPE
 PBB encap. of incoming frames terminated at far-end nPE

 Ethernet frames in VPLS/H-VPLS core use 802.1ah format
 Thus, VPLS core operation is modified


Metanoia, Inc.
H-VPLS w/ PBB Migration 802.1ah Critical Systems Thinking™

Frames in Core: Operation & Protocols
Q-in-Q PBB
I-Comp I-Comp

B-Comp B-Comp
CE

MPLS
X IP/MPLS
X
MPLS
A1 C1 IB-BEB D1 MPLS IB-BEB B1
MPLS
I/f I/f

Must terminate PBB Must support PWs per VPLS Must terminate
Spoke PWs per customer and MPLS/PW only VPLS instance PBB and
(one service per PW) MPLS/PW

LSP-Label LSP-Label LSP-Label
C-DA
VC-Label VC-Label VC-Label

B-DA B-DA B-DA

B-SA B-SA B-SA

LSP-Label LSP-Label B-Tag B-Tag B-Tag
C-DA
VC-Label VC-Label I-Tag I-Tag I-Tag







Metanoia, Inc.

 Use Case: SP has converged to MPLS in core and aggregation n/ws, and
wishes to have the benefit of PBB scaling in the VPLS core
 Useful for the operator whose MPLS access/aggregation networks are being
upgraded to support PBB IB-BEB at uPEs

Benefits Drawbacks
 Reduces MAC learning at nPEs  Must upgrate nPEs of all existing
 Due to PBB at nPEs, thus giving MPLS access/aggregation n/wks
MAC address scalability  nPE needs IB-BEB functions

 Lowers PW mesh counts in core
 Multiple customer instances can
be bound to a single B-VLAN and
VPLS instance


Metanoia, Inc.
H-VPLS with PBB Migration: Mixed Critical Systems Thinking™

 Existing 802.1ad access/aggregation n/wks unchanged
 Exchange Ethernet frames with 802.1ad format over PWs in core

 nPE’s must be upgraded for PBB-based processing (IB-BEB)
 All Ethernet svc frames over VPLS core are PBB-encapsulated

 New MPLS-based access/aggregation networks have PBB functionality on
uPE
 Exchange PBB-encap frames over VPLS core

 Interworking b/ween PBB-capable and PB-capable requires that nPE of
PBB network has IB-BEB functionality

 Ethernet frames in VPLS/H-VPLS core use 802.1ah/802.1ad format


Metanoia, Inc.
H-VPLS w/ PBB Migration Mixed Critical Systems Thinking™

Frames in Core: Operation
PBB Q-in-Q

Q-in-Q PBB
I-Comp I-Comp

B-Comp B-Comp
CE

MPLS
X B-BEB IP/MPLS
X
MPLS
A1 C1 IB-BEB D1 MPLS
MPLS IB-BEB B1
I/f I/f

Spoke PWs per customer -- Must terminate PBB and MPLS/PW Must support PWs per VPLS
(one service per PW) Must terminate
only VPLS instance PBB and
-- Needs IB-BEB and B-BEB capability MPLS/PW

-- Should be aware of remote PEs’
capabilities – via static config . or
extended VPLS control plane

Non-PBB Capable PBB- Capable
Existing Access Networks New Access Networks

Protocol stack is a combination of those
shown earlier for 802.1ad and 802.1ah in core


Metanoia, Inc.

 Use Case: SP has converged to MPLS in core and aggregation n/ws, has a mix
of PB- and PBB-capable access/aggregation networks

Benefits Drawbacks
 Core can serve both PB-encapsulated  Must upgrate nPEs of PBB-capable
and PBB-encapsulated frames access/aggregation n/wks. nPE needs
 IB-BEB to interface with PBB network
 B-BEB to interface with PB network
 Lowers PW mesh counts in core
 For PBB-capable aggregation networks
 PE must be aware of remote peer’s
capability
 Requires either static config. or VPLS
control plane extensions


Metanoia, Inc.

Workshop Outline

MPLS-TP

 Overlay
 Parallel
 Uniform
 Mobile-Backhaul


Metanoia, Inc.

Mobile Backhaul Architectures
 Mobile backhaul architectures derive from the basic and
hybrid architectures presented earlier

 We examine them separately due to their unique needs:
 Interface with the core network
 Timing and synchronization requirements
 Evolution requirements – from TDM or ATM to IP/MPLS and/or
Ethernet


Metanoia, Inc.

Evolution of Cellular Technology: 2G to 4G
 2G
 GSM (TDM, 56-114 kbps)

 2.5G
 GPRS, EDGE (TDM, 236-473 kbps)
 CDMA 1XRTT (HDLC, TDM, 144 kbps)

 3G
 WCDMA/UMTS (3GPP) (R99, R4) (ATM, 384 kbps uplink, 2Mbps downlink)
 UMTS (3GPP) (R5 (HSDPA), R6 (HSUPA))( IP, 2-3 Mbps)
 EV-DO (3GPP2) (Rev0, RevA, RevB, RevC) (IP, 1.8 Mbps uplink, 3.1Mbps
downlink)

 4G (LTE)
 3GPP (R7/R8) (IP, >50 Mbps uplink, >100 Mbps downlink)
 WiMAX (802.16e, 802.16m) (IP, 50-100 Mbps)

Metanoia, Inc.
Evolution of Cellular Technology Critical Systems Thinking™

and Backhaul Types
Network Speed Interface

GSM/GPRS 56-114 Kbps TDM

EDGE 236 – 473 Kbps TDM

3G (UMTS/ 384 Kbps Uplink
ATM
WCDMA) R3, R4 384 Kbps Downlink
3G, R5 (HSDPA), 384 Kbps Uplink
IP/Ethernet
R6 (HSUPA) 14.4 Kbps Downlink
500 Mbps Uplink
LTE R8 (20 Mhz) IP/Ethernet
>100 Mbps Downlink

CDMA1X-RTT 100 Kbps TDM Legend

CDMA EV-DO 1.8 Mbps Uplink 2G
IP/Ethernet
Rev A/B 1.8 to 5 Mbps Downlink 2.5G
WiMAX (10 Mhz) 50 Mbps IP/Ethernet 3G
4G
Backhaul Types

Metanoia, Inc.

Mobile Backhaul Components
 Backhaul network – defined as the network that connects
 Base Transceiver Station (BTS, or Base Station) to Base Station Controller
(BSC) in 3GPP2 – GSM-based cellular networks
 Node-B to Radio Network Controller (RNC) in 3GPP – CDMA-based cellular
networks

 Traditional backhaul networks have used ...
 E1/T1 leased lines
 SONET/SDH TDM channels (for higher rate aggregation)

 Mobile transport infrastructure has hitherto been ...
 Microwave links
 Optical fiber with SDH/SONET

 Evolution to packet-based wireless services creates a push for the
transport itself to be packet-based: Ethernet or IP/MPLS or a combination


Metanoia, Inc.

Traditional Backhaul Evolution
2G BTS

BSC

TDM
TI/EI Cellsite SONET/SDH SONET/SDH
Gateway XConnect XConnect E1

T1/E1/STM SDH/SONET
Network
ATM RNC
ATM

nxE1

ATM
3G BTS Switch

Separate transmission facilities for different
technologies (TDM and packets)


Metanoia, Inc.

Mobile Backhaul Challenges
 Exponential growth in mobile subscribers
 3 Billion subscribers (2007)
 Expected to touch 5 Billion by 2013!
 Leads to massive increase in traffic volume

 Shift in mobile traffic patterns
 High-speed data, including multimedia traffic (video, VoIP, IMS)
 Bandwidth insensitive but QoS sensitive applications!
 With increasing speed, revenue-per-bit is decreasing
 Result is that traffic and revenue are decoupled !

 These trends lead to massive increase in traffic volume

 Backhaul accounts for 30% of OpEX (Per Yankee Group 2005)

 Traditional backhaul unsustainable with such traffic growth

Metanoia, Inc.
Key Performance Requirements Critical Systems Thinking™

for Mobile Backhaul
 Delay – budget for entire RAN is 100ms
 Backhaul segment delay must be < 3-4 ms

 Loss – Target BER is
 2G networks = 10-7
 3G networks = 10-5 to 10-4

 Synchronization – Frequency and Time accuracy
 2G: 50 ppb freq. accuracy at radio interface
 3G: 50 ppb freq. accuracy and 2.5 µs time accuracy for TDD
 WiMAX: 8 ppm freq. for FDD/TDD, and 5-25 µs time accuracy for TDD


Metanoia, Inc.

Backhaul Strategy Fundamentals
 Future-Proof
 Should support existing legacy (TDM) infrastructure
 Evolving new packet-based and IP services using diverse and
coexistent technologies

 Scalable
 Grow b/w to support next-gen. wireless access technology LTE/4G
 Ethernet interfaces versus nxT1/E1

 Cost Effective – reduce OpEx

 Must meet timing and synchronization targets

 Simplify provisioning & planning – advanced OAM,
troubleshooting

Metanoia, Inc.

Timing and Synchronization
 ITU-T G.8261 specifies timing & synchronization in packet
networks

 Synchronization needed for
 Radio framing accuracy, hand-off control, backhaul transport
reliability

 Three Methods
 Synch. Ethernet: Similar to SONET/SDH -- embed clock in PHY layer
 Requires changes in PHY chip

 IEEE 1588 (Precision Time Protocol)
 Distributed protocol: specifies how real-time PTP clocks synchronize

 IEEE 802.1as
 Aimed at adapting IEEE 1588 to Carrier Ethernet

Metanoia, Inc.

Clock Distribution Methods Used
 Physical Layer Clock
 Via synchronous TDM i/fs e.g. PDH/SDH/SONET
 Via Sync. Ethernet as per G.8261/G.8262

 GPS-receiver based synchronization

 Clock distribution over packet network
 IEEE 1588v2 – being looked at in ITU-T Q13/SG15, who are developing
a telecom profile for 1588 v2
 NTP – IETF currently working on NTP v4

 Adaptive and Differential clock synchronization


Metanoia, Inc.

Packet Transport for Mobile Backhaul
 Packet-based transport can provide high bandwidth at lower
cost (than TDM transport)

 Ideal choice for LTE and 4G technologies

 Challenges ...
 Support legacy traffic (TDM and ATM ) via circuit emulation
 Meet timing and synchronization requirements
 Provide QoS and protection switching
 Furnish advanced OAM capabilities


Metanoia, Inc.

Pseudowires (PW) for Legacy Transport
PW
PSN Tunnel

BSC
AC AC
Carrier Ethernet Wireless
CE Network Core
PE PE
(BTS)

AC: Attachment Ckt CE : Customer Edge (BTS)
PE: Provider Edge BSC: Base Station Controller

 Encapsulation  PSN Tunnels

 May be IP/MPLS, T-MPLS/MPLS-TP, or
Structure-Agnostic TDM-over-IP
PB/PBB/PBB-TE based
(SAToIP) (RFC 4553)
 Structure-Aware TDM Circuit
 PW Signaling
Emulation (CESoPSN) (RFC 5086)
 ATMoPSN (RFC 4717)


Metanoia, Inc.

PBB/PBB-TE for Mobile Backhaul
 Connection-oriented p2p tunnels b/ween BTS (BS) -- BSC (NC)
 Provides MEF-style EVPL/EVP-Tree between RAN BS and RAN NC

 IEEE 802.1ag OAM enables carrier-grade OAM tools

 Delay/loss ensured via admission control & 802.1Q PCP

 Supporting Legacy TDM over PBB/PBB-TE
 IETF has draft on PW over PBB-TE
 802.1ah supports encap. of non-Ethernet frames (via short I-TAG TCI)


Metanoia, Inc.

PBB/PBB-TE for TDM Encapsulation
IEEE 802.1ah PBB Short & Long I-Tag

DEI I-SID
C-DA C-SA
Etc. (Service Identifier)

Long I-TAG Tag Control Information

DEI I-SID
Etc. (Service Identifier)

Short I-Tag
(Only I-SID used for encapsulation of multiple protocols)

EtherType used to indicate encapsulation of Ethernet or multiple protocols

We show I-SID with C-DA and C-SA but without Ethernet encapsulation


Metanoia, Inc.

MEF Services for Mobile Backhaul
RNC RNC

BSC BSC

Service
Multiplexing mp2mp EVC

Metro Ethernet
EVC EVC Metro Ethernet

BTS
BTS BTS BTS
BTS
EVPL Service for Backhaul using EP-LAN Service for Backhaul using
Metro Ethernet Networks Metro Ethernet Networks

Services muxed at RNC UNI Needed when inter-BS communication
is permitted like in LTE/802.16m (WiMAX)

Metanoia, Inc.

MEF Services for Mobile Backhaul
RNC

BSC

Service
Multiplexing

Metro Ethernet
EVC EVC

BS/ BS/ BS/
BTS BTS
BTS

EP-Tree Service for Backhaul using
Metro Ethernet Networks

Metanoia, Inc.

IP/MPLS for Mobile Backhaul
 MPLS PW/VPLS can provide effective backhaul
 Traditional circuit-based services are offered using PWs

 PW signaling – uses either BGP or LDP

 Protection switching
 Achieved via MPLS Fast Reroute (FRR) on LSP tunnel

 OAM provided by
 LSP Ping, VCCV
 BFD

Metanoia, Inc.

IP/MPLS and PBB/PBB-TE Caveats
 Poor support for P2MP LSPs in MPLS
 Such support is desirable:
 For Clock Distribution from BSC to BTSs

 When BSs allowed to communicate with each other and cooperate
as in WiMAX/LTE

 PW over PBB-TE is not fully developed


Metanoia, Inc.

Migration Strategies for Service Providers
 HSDPA/3G Data Off-load
 Separation of transport
 GSM/UMTS voice sent over SONET/SDH

 Data traffic transported over PSN tunnel

 Packet-based Backhaul
 TDM/ATM/Ethernet/IP all transported over PSN tunnel via PWs

 Converged Transport
 Single packet-switched infrastructure for wireline, broadband
and mobile services


Metanoia, Inc.

HSDPA/3G Data Off-Load
2G BTS

TDM
TI/EI

Multi-Service
Cellsite SONET/SDH SONET/SDH Aggregation
Gateway XConnect XConnect Router 2G BSC

TI/EI/STM SDH/SONET
Network
3G RNC Wireless Core
ATM
nxE1

Ethernet
Carrier Ethernet
3G BTS Network
Ethernet Ethernet
Switch Switch


Metanoia, Inc.

Packet-Based Backhaul
2G BTS

BSC

TDM
Cellsite
Gateway
PE PE

ATM Carrier Ethernet
TI/EI/STM Network (PSN) RNC/GW

Ethernet

3G/4G IP/ATM/Ethernet/TDM are all transported over the PSN
BTS Tunnel using PWs


Metanoia, Inc.

Converged Packet-Based Transport

Converged Service
Delivery Platform
3G/4G Base
Station Aggregation
Converged
Network
Metro Core

Internet
Access
Network

Common packet-switched infrastructure for both wireline
and wireless services

Metanoia, Inc.

Backhaul References
 MEF White Paper, “Carrier Ethernet Access for Mobile Backhaul Networks”, Feb
2008.

 MEF Technical Specification Draft 2, “Mobile Backhaul Implementation Agreement-
Phase 1”, Feb 2008

 Nortel Networks White Paper, “Mobile Network Evolves with Carrier Ethernet”, 2008.

 ITU-T G.8261, “Timing and Synchronization Aspects in Packet Networks”, Sept 2007.

 IP/MPLS Forum White Paper, “Use of MPLS Technology in Mobile Backhaul
Networks”, Feb 2008

 Kireeti Kompella and Mallik Tatipamula, “IP/MPLS in Next Gen Mobile Backhaul
Networks”, MPLS 2007.


Architectural Options for Metro Carrier-Ethernet Network Buildout: Analysis & Evaluation

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