Provider Backbone Transport

1 Nortel Confidential Information

Provider Backbone Transport

Alan BeardDir Business Development19th November 2007


What’s in common between…

Triple play - DSLAM Connectivity

ATM DSLAMsDSLAM

Data Business Services Wireless Backhaul

?

??

Triple Play - Fibre To The Home

?


> Ethernet VPNs

> Any-to-any L2 connectivity

> Cost effective alternative to L3 VPNs

> Simple to manage and operate

> Scalable bandwidth

> Improved security through L3 transparency

3RD GENERATION

> IP-VPNs

> RFC2547 based

> Connectionless

> Hosted service

> Layer 3 adds complexity

2ND GENERATION

VPN Evolution

> Virtual LeasedLine (VLL)

> ATM/Frame Relay

> Shared bandwidth

> Cost effective alternative to leased lines

> Multiple connections create complex mesh

1ST GENERATION


Network Layer Reduction (Metro)

Layer 0 – Wavelength

Layer 1/2 – Ethernet – PBB/PBT

Layer 3 – IP

Layer 0 – Wavelength

Layer 1 – SDH

Layer 2 – Ethernet

Layer 3 - IP

Layer 1.5 – GFP, LCAS, VCAT

TODAY


Ethernet Solutions

Ethernet as a Service

> Offered and sold as connectivity

> Aimed at Business Market Services• Ethernet VPNs

• Ethernet Private Line• Ethernet Virtual Private Line• Ethernet Virtual Private LAN

Ethernet as an Infrastructure > Support of Residential and Business

Services• Triple Play: Voice/Video/Data• Internet Access• Storage

> Metro Aggregation• DSL Aggregation• Wireless Backhaul• Internet Access and IP VPNs

Service Provider Voice

ASP

Data

Video

CE

CE

Point-to-Point EVC

UNI

UNI

E-Line Service type


Enterprise-class Ethernet Switches Lack Critical Service Provider Pre-requisites

Existing Ethernet Challenges: Existing Ethernet Challenges:

Overlapping addresses; Secure separation & demarcation of

customers & provider

Service Scalability

OAM equivalent or better than current provider OSS systems

Traffic Engineering & QoS

Carrier-grade resiliency with bandwidth efficiency

Lower Cost per MbpsReduced CAPEX

Reduced OPEX & Simplified OAM

Higher Service Scalability & Flexibility

Traffic EngineeringResource ReservationDynamic ProvisioningDifferentiated Services Network Resiliency

Ethernet as used today is lowest cost but has several issues:


Nortel’s Carrier Ethernet Solution

Guaranteed SLAs &

determinism via PBT

Carrier-class OAM

Customer encapsulation

(PBB/PWE)

Keep Ethernet Simple & Cost Effective


IEEE 802.1ah EncapsulationProvider Backbone Bridging

Ethernet Header Payload

802.1Q Tag

1. Q tag identifies VLAN

EthernetHeader

OuterTag

802.1Q Tag

Payload2. Service Provider Q tag identifies customer

802.1ahHeader

EthernetHeader

802.1Q Tag

Payload3. Customer frame is transparently tunneled from UNI to UNI


IEEE 802.1ah (PBB) Encapsulation

>Scalability • 16 million VPNs

>Security• Clear demarcation between service

provider and customer

>Robust• Spanning Tree Protocol convergence in

the customer network doesn’t affect service provider network

>Service management• Service provider MAC provides an end to

end service ID• Provided simple efficient Any to Any

service

Characteristics


Nortel’s Strategy

> Ethernet switches are the telecommunications infrastructure with the lowest cost point

> We can re-purpose these switches with new control software to meet carrier needs

> This can be done with minimal changes to Ethernet standards and those changes are in progress

> This can be done while preserving investment in service provisioning

Keep Ethernet simple, flexible and cost effective


Provider Backbone Transport (PBT)

> A simple point-to-point Ethernet tunneling technology• Reserve bandwidth• Deliver hard QoS • Offer 50 ms recovery

Provides “SDH like” guaranteed performance & SLAs

Carrier Ethernet

Traffic Engineered PBT trunks

Trunk manager


How Does PBT Work?

> Turn off • Broadcast unknown• MAC learning functionality• Spanning Tree Protocol

> Give control of the forwarding tables to the Provisioning system

> Ethernet still switches based on forwarding table information

Forwarding/Data

Signaling/Control

Management

Reuses existing Ethernet hardware and cost points


PBT Example

> Normal forwarding using: destination MAC address + VLAN-ID(DA + VLAN-ID)

> PBT reserves a subset of VLAN tags• VLAN tag is no longer globally unique

Service and Network Management

SA: PE1Trunk defined by DA: PE3 + VLAN 45

CustomerNetwork

MAC-in-MACencapsulation

CustomerNetwork

Trunkmanager


Combination of VLAN tag and MAC address is unique


Service and Network Management

CustomerNetwork


CustomerNetwork

Trunk manager

PBT Example

> Backup path can be configured for resiliency• Paths can use the same Destination MAC

> Both paths are monitored by CFM control frames• active path forwards packets• if CFM measures active path down, switchover to backup in 50ms




The End Result

> Solves MAC learning problems• MAC Explosions, Service Scalability

> New forwarding mode results in • Traffic engineering• Resiliency• Hard QoS

> Comprehensive OAM• Ethernet OAM is on track to surpass MPLS OAM

Low risk play…..reuses existing Ethernet switches


MPLS ServicesMPLS Services(RFC 2547 VPN, PWs etc.)(RFC 2547 VPN, PWs etc.)

Ethernet ServicesEthernet Services(EVPL, ELAN, ELINE, Multicast)(EVPL, ELAN, ELINE, Multicast)

> Keep existing Ethernet & MPLS services

> Capitalize on Ethernet as transport for significant savings

> Existing network-friendly solution!

PBTPBT

Nortel Technology Innovation: Provider Backbone Transport


Back Up


MPLS Dissected: 2 separate layers

1. MPLS provides a Service Layer• Revenue generating• L3 VPNS (2547), L2 VPNs (PWs, VPLS)

2. MPLS also provides a Tunnel layer• Provides networking functionality• Adds significant cost to your equipment and

operations teams• Can we eliminate this layer of cost for

metro transport? Yes!

MPLS Tunnel Layer

Customer Payload

MPLS Service Layer

L1 Header

Ethernet Header


The Virtues Of Tunneling

PBT HEADER

PW over PBTVFVF

PWsPWs

VPLS over PBTVSIVSI

VPLSVPLS

PBB over PBTI-SIDI-SID

PBBPBB

Ethernet Surpasses MPLS:

MPLS Tunnel Layer

Customer Payload

PseudowireService Label

L1 Header

Ethernet Header

VPLS PBB (802.1ah)Any Service!

PBT works with any service layer


Ethernet OAM

> 802.1ag gives:• Rapid notification of end-to-end connectivity failure.• Where is broken link?• MTU/priority-related faults→ Faults found & fixed quicker & more easily.

> Y.1731 measures:• Frame delay, delay variation, frame loss• AIS→ Diagnostics/monitoring to support premium high-QoS services

> Resiliency and Protection switching (ITU G.8031)• Provides 50ms protection switching

> 802.1ab Autodiscovery→ fast and accurate network topology view

“SDH Like” simple operational paradigm - Functionality is on the box, EMS/NMS not involved


EMS - Metro Ethernet Manager (MEM)

Integrated Carrier Ethernet / Optical / MSS management platform


PBT Standards

> PBT architecture uses existing standards

> The remaining areas are being addressed by the IEEE and ITU-T

• IEEE approves work on PBT PAR (November 06)• IEEE working group launched Jan07.

• G.pbt Provider Backbone Transport Architecture introduced in February 06


Standards Body

Standards Project Approved Draft Under Discussion

802.1AB Discovery

802.1ad Provider Bridges

802.1ag Connectivity Fault Management

802.1ah Provider Backbone Bridges

Y.1731 Ethernet OAM Mechanisms

G.8031 Ethernet Protection

Standards Summary

PBT on target to be standardised in 2007


Documents

Provider Backbone Transport