3. PWE3 Introduction for OptiX RTN 910950 ISSUE 1.00

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Copyright 2009 Huawei Technologies Co., Ltd. All rights reserved.

PWE3 Introduction for OptiX RTN 910/950


Foreword

z In the OptiX RTN 910/950, all kinds of the services are

loaded by the MPLS tunnel.

z How to encapsulate the different service frames into the

uniform MPLS tunnel?

z How is the interconnection between OptiX RTN 910/950 to

other TDM or data communication networks ?


Objectivesz Upon completion of this course, you will be able to:

Describe the basic concepts of PWE3

Outline the typical PWE3 encapsulation format for TDM,

Ethernet and ATM services

Outline the PWE3 application scenarios of OptiX RTN 910/950


Contents1. PWE3 Overview

2. TDM Service to PWE3

3. ATM Service to PWE3

4. Ethernet Service to PWE3

5. PWE3 Application Scenarios



1.1 Basic Concepts

1.2 Functions of PWE3


Position of PWE3

Tunnel

BTSBTS

SDHSDH

RouteRouterr

C STM-1

ATM E1

Eth.

PWE3

MPLS

MPLS

PWE3

RNC

SDHSDH

RouterRouter

ATM E1

Eth.

C STM-1

OptiX RTN 950

OptiX RTN 950

PW label MPLS labelEth. packet ATM CellTDM frame


PWE3 Basic Conceptsz Pseudo-Wire Emulation Edge to Edge (PWE3)

AC: Attachment Circuit

Forwarder

PW: Pseudo Wire

PW signaling

CE: Customer Edge

PE: Provider Edge

CW: Control Word

VCCV: Virtual Circuit Connectivity Verification


PWE3 Working Procedurez Pseudo-Wire Emulation Edge to Edge (PWE3)

IP/MPLS IP/MPLS

CE1

CE2 CE4

CE3VPN1VPN1Site1Site1

VPN2VPN2Site1Site1

VPN1VPN1Site3Site3

VPN2VPN2Site4Site4

PE1 PE2

TunnelAC

PWPW Signaling

Forwarder ForwarderPP

Emulated ServicePW LabelTunnel Label


Reference Model of PWE3 Network

PE1

CE1 Tunnel CE2

Emulated Service

Pseudo Wire

PSN Tunnel

PE2

Native Service

Native Service

Custom Edge 1

Custom Edge 2

Provider Edge 2

Provider Edge 1

AC AC


PWE3 Protocol Stack

Payload Encapsulation

Emulated Service

(TDM, ATM, Ethernet, etc)

PSN Tunnel, PSN & Physical

Layers

Emulated Service

Pseudo Wire

PSN Tunnel

Payload Encapsulation

Emulated Service

(TDM, ATM, Ethernet, etc)

PSN Tunnel, PSN & Physical

Layers

PSN

Tunnel Label EXP S TTL

PW Label EXP S TTL

Control Word

Emulated Service

...


Functions of PWz Functions of PW

Encapsulate the emulated service from CEs

Carry the encapsulated service to the transmit tunnel

Set up PW at the tunnel end

Perform PW-related QoS

Manage signaling, timing and sequence at the PW edge

Manage the status specified by the service and alarms


PWE3 Advantagez Generic label, which provides a uniform multi-service

network data transport platform and reduces the operating

cost

z Investment protection, which provides the backward and

forward compatibility of network services

z Private line emulation, which provides operators with

network services of great return.


Summaryz The position of the PWE3 in services processing of OptiX

RTN 910/950

z The concepts of PWE3

z The service processing procedure of PWE3

z The functions and advantages of PWE3


E1 Service Typesz Unframed E1

Using all the time slots as a whole to transmit user data.

z Framed E1

Time slot 0 used for signaling and frame delimiters

Time slot 1-31 can be used for transmit service data for

different users


TDM Circuit Emulationz SAToP

Structure-agnostic TDM over packet

Defined in RFC 4553

z CESoPSN

Structure-aware TDM circuit emulation service over packet

switched network


SAToP

z SAToP supports both unframed and framed E1 service

at UNI side

Byte mByte m+1

Byte m+nx32-1

Tunnel Label PW Label

Control Word Payload

4 bytes

4 bytes

4 bytes

Payload

ETH header

CRC

Payload

PPP header

FCS

UNI E1 MPLS Tunnel NNI Interface


SAToP Frame Format

Tunnel Label EXP 0 TTL

PW Label EXP 1 TTL

Control Word

RTP Header

Time Stamp

SSRC Identifier

E1 Frame 1

E1 Frame 2


CESoPSN

z CESoPSN supports only the framed E1 service at UNI

side

UNI E1 MPLS Tunnel NNI Interface

Tunnel Label

PW Label

Control Word

Payload

#1 E1 Frame

#2 E1 Frame

#n E1 Frame

32 bytes32 bytes

32 bytes

4 bytes

4 bytes

4 bytes

Payload

ETH header

CRC

Payload

PPP header

FCS


CESoPSN Frame FormatTunnel Label EXP 0 TTL

PW Label EXP 1 TTL

Time Slot 2 Time Slot 3 Time Slot 4

Time Slot N (Frame 1#)

Time Slot 1 Time Slot 2 Time Slot 3 Time Slot 4

Time Slot N (Frame 2#...)

Time Slot 5

Time Slot 5

Control Word

RTP Header

Time Stamp

SSRC Identifier

Time Slot 1


CES Service Application

IP/MPLS IP/MPLS

E1E1

E1E1

PWPW

PWPW

C STMC STM--11

PE1PE1

PE2PE2

PE3PE3 BSCBSC

E1E1

BTS1BTS1

BTS2BTS2

PWPW


Questionsz List the difference between SAToP and CESoPSN.


ATM Service Encapsulation

The types of encapsulation supported by the OptiX RTN

910/950:

ATM Service Payload

Control Word (ATM)

Pseudo Wire Header

PSN Transport Header 4 bytes

4 bytes

4 bytes

No. PW Type Indication3 0x0003 ATM transparent cell transport (V1R2)

9 0x0009 ATM n-to-one VCC cell transport

10 0x000A ATM n-to-one VPC cell transport

12 0x000C ATM one-to-one VCC Cell Mode

13 0x000D ATM one-to-one VPC Cell Mode


N-to-One Cell ATM Modez The encapsulation format of a single cell is required (fast

encapsulation), the encapsulation format of multiple cells is

optional.

Payload (48 octets)

CPTIVCIVPI

Payload (48 octets)

VCI CPTIVPI

Sequence NumberLengthResFlags0 0 0 0Pseudo Wire Header in PWE3

PSN Transport Header PWE3


One-to-One ATM Cell Modez One PW can carry one VPC/VCC

z The format can be the single cell format or multiple cells

encapsulation

Payload48 octets

CPTIRESVM

Payload48 octets

Sequence Number CPTIRESVMResvd0 0 0 0Pseudo Wire Header in PWE3

PSN Transport Header in PWE3

CV PTIRESM VCI

Payload48 octets

Payload48 octets

VCI

VCISequence Number CPTIRESVMResvd0 0 0 0

Pseudo Wire Header in PWE3PSN Transport Header in PWE3


Ethernet Service Encapsulation

z Control words, which are only sorted (165535).

z The equipment support the modes without control words or with control words.

z The control words can be set at the PEs on the two ends through signaling or manual configuration.

Tunnel label EXP 0

PW label EXP 1 TTL

Reserved Sequence Number

TTL

0000

Ethernet Payload

( Variable length )


TDM Service Emulation

E1

CESoPSNSAToP

Abis

TDM

PWE3

MPLS

PPP/

ML-

PPPHDLC

POS/E1

PSNPSN

Abis

TDM

E1

STM-1

Abis

TDM

E1/ch

STM-1

Abis

TDM

PWE3

Tunnel

Line Interface Line InterfaceNetwork Interface

E1E1

MAC

GE

TS# 1-9

Idle TS suppression

--

TS# 1-6

Idle TS suppression

TS# 1-8

Idle TS suppression

--

--

--

--

--

1+1/1:1 APS

E1/POS/GE/ch STM1 MSPPoC3 PoC1

--

--

--

idle timeslot regenerated

2G BTS

BSC


ATM/IMA Service Emulation

E1E1E1

E1

lub UP

AAL2

ATM

PWE3

MPLS

---


E1E1

PoC3

lub UP

AAL2

ATM

IMA

E1

lub UP

AAL2

ATM

PWE3

N:1 ATM PWE3 Encapsulation

lub UP

AAL2

ATM

STM-1

PSNPSN

STM-1

EF

AF3BE

Legend

1+1/1:1 APS

Tunnel

PoC1

E1/POS/GE

3G Node B

RNC

3G Node B


Ethernet Service Emulationlub UP

802.1Q

Eth

PWE3

MPLS

---


lub UP

802.1Q

EthN:1 Eth PWE3 Encapsulation

PSNPSN

EF

AF3BE

Legend

1+1/1:1 APS

Tunnel

lub UP

802.1Q

Eth

PWE3

GE/FE

lub UP

802.1Q

Eth

GE

PoC3 PoC1

E1/POS/GE

3G Node B

RNC


Summaryz PWE3 basic concepts

z TDM Service to PWE3

z ATM Service to PWE3

z Ethernet Service to PWE3

z PWE3 Application

Thank youwww.huawei.com

PWE3 Introduction for OptiX RTN 910/950ForewordObjectivesContentsContentsPosition of PWE3PWE3 Basic ConceptsPWE3 Working ProcedureReference Model of PWE3 NetworkPWE3 Protocol StackFunctions of PWPWE3 AdvantageSummaryContentsE1 Service TypesTDM Circuit EmulationSAToPSAToP Frame FormatCESoPSNCESoPSN Frame FormatCES Service ApplicationQuestionsContentsATM Service EncapsulationN-to-One Cell ATM ModeOne-to-One ATM Cell ModeContentsEthernet Service EncapsulationContentsTDM Service EmulationATM/IMA Service EmulationEthernet Service EmulationSummary

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3. PWE3 Introduction for OptiX RTN 910950 ISSUE 1.00