76 8600 50110f 8600 smart routers ATM and TDM configuration guide

Changes applied in5.1 Redundancy Group.76.8600-50110D 19.12.2013 Renewed related documentation table in8600 Smart Routers Technical Documentation.Changes and updates applied in1.3 PWE3 T

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ATM and TDM Configuration Guide

76.8600-50110F 12.05.2015

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Revision History Document No Date Description of Changes

76.8600-50110F 12.05.2015 Reworked1 Pseudowire Emulation Edge-to-Edge (PWE3)and

2 Pseudowire Redundancy Ethernet PWE3 related content moved

to 8600 Smart Routers Ethernet Configuration Guide.

Added1.2 Virtual Circuit Connectivity Verification Overviewand2.4.6 PWE3 Redundancy Counters

Changes applied in: 1.3 PWE3 Types,5 PWE3 RedundancyConfiguration Examples

Additions and changes in6.9 Limitations and Restrictions.Updates in4 MS-PWE3 Configuration Examplesand8.2.2 CESoPSN

76.8600-50110E 29.10.2014 Added 8602 Smart Router and 8615 Smart Router functionality in

1.3 PWE3 Types.Added 8602 Smart Router functionality in2 PseudowireRedundancy

Added clarification of PWE3 redundancy being not supported inANSI mode, LAG and QinQ AC points in2.3 Limitations andRestrictions

Changes and updates applied in6 ATM Overview.Added clarification of VCG configuration in ATM and MS IFMs in6.9 Limitations and Restrictions

Changes applied in5.1 Redundancy Group.76.8600-50110D 19.12.2013 Renewed related documentation table in8600 Smart Routers

Technical Documentation.Changes and updates applied in1.3 PWE3 Types.Added support of PWE3 redundancy in 8605 Smart Router, 8609Smart Router and 8611 Smart Router Corresponding updatesmade in:

• 2.2 Supported Functionality

• 5.2 T-PE Nodes ConfigurationAdded single-homed and dual-homed PWE3 redundancy scenarios

in2.1 Overview.Added Ethernet PWE3 redundancy support in2 PseudowireRedundancy

Added support of PWE3 redundancy for Ethernet over(ML)PPP sub-port on the 24xchE1/chT1 MS IFM in ETSI mode2.2 Supported Functionality

Added Ethernet PWE3 redundancy restrictions in2.3 Limitationsand Restrictions

Renewed3 Single-Segment PWE3 Configuration Examplesandadded3.5 SS-PWE3 Provisioning Status

Renewed4 MS-PWE3 Configuration Examplesand added4.5 MS-PWE3 Provisioning Status

Added PWE3 redundancy configuration options and basic settings

of the trunk interfaces per each node in5 PWE3 RedundancyConfiguration Examples Added Ethernet PWE3 redundancygroup syntax in5.1 Redundancy Group

Updated and clarified ATM circuits scalability inCircuitScalability

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8605 Smart Router FP1.6

If a different feature pack of 8600 Smart Routers is in use, please refer to the relevant productdocument program on the Coriant Portal by navigating towww.portal.tellabs.com> ProductDocumentation > Data Networking > 8600 Smart Routers > Technical Documentation

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Terms and Abbreviations Term Explanation

AAL ATM Adaptation Layer

AC Attachment CircuitADSL Asymmetric Digital Subscriber LineAIS Alarm Indication Signal

AJB Adaptive Jitter BufferAPS Automatic Protection SwitchingATM Asynchronous Transfer ModeBFD Bidirectional Forwarding DetectionBRAS Broadband Remote Access ServerCAC Connection Admission ControlCAS Channel Associated SignallingCBR Constant Bit Rate

CC Control ChannelCDV Cell Delay VariationCDVT Cell Delay Variation Tolerance

CE Customer EquipmentCESoPSN Circuit Emulation Service over Packet-Switched NetworkCLI Command Line Interface

CLP Cell Loss PriorityCLR Cell Loss RateCTC Common Transmit ClockCTD Cell Transfer DelayDCN Data Communication NetworkDHCP Dynamic Host Configuration ProtocolDiffServ Differentiated Services

DS1 Digital Signal level 1 (T1)DS3 Digital Signal level 3 (T3)DSL Digital Subscriber LineDSLAM Digital Subscriber Line Access MultiplexerEMS Element Management System

FEC Forwarding Equivalence Class

FM Fault Management

FR Frame Relay

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FRR Fast-RerouteGFC Guaranteed Frame ControlGFR Guaranteed Frame RateHEC Header Error ControlHSDPA High-Speed Downlink Packet AccessICP IMA link Control Protocol

IETF Internet Engineering Task ForceIFC Interface Module Concentrator is the line card baseboardIFC line card The IFC line card in 8630 Smart Router and 8660 Smart Router and consists of an

IFC and up to two IFMs There are two types of IFC line cards: IFC1 and IFC2IFM Interface Module, specific term of the module which can be placed on the line card

and which consists of the physical interfacesILMI Interim Local Management InterfaceIMA Inverse Multiplexing for ATM

IP Internet ProtocolIPCP IP Control ProtocolIPoATM IP over ATMISP Internet Service ProviderITC Independent Transmit ClockIWF Interworking FunctionLAG Ethernet Link AggregationL2TP Layer 2 Tunnelling ProtocolLDP Label Distribution ProtocolLLC Logical Link ControlLNS L2TP Network ServerLOPS Loss of Packet StateLSP Label Switched PathMBS Maximum Burst SizeMC-APS Multi-Chassis APSMCR Minimum Cell RateMPLS Multiprotocol Label SwitchingMSP Multiplexer Section ProtectionMS-PWE3 Multi-Segment PWE3

MTU Maximum Transmission Unit

NE Network ElementNNI Network to Network InterfaceNSP Native Service Processing

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OAM Operation, Administration and MaintenanceOCD Out of Cell Delineation

OSPF Open Shortest Path FirstP12s Framed G.704 signalPCR Peak Cell RatePDH Plesiochronous Digital Hierarchy

PE Provider Edge

PM Performance MonitoringPNNI Private Network to Network InterfacePPP Point-to-Point Protocol

PPPoATM PPP over ATMPPPoETH PPP over EthernetPPPoET-

HoATM

PPP over Ethernet over ATMPSN Packet-Switched NetworkPTI Payload Type IdentifierPWE3 Pseudowire Emulation Edge to EdgeQoS Quality of Service

RNC Radio Network ControllerRSVP Resource Reservation ProtocolRTP Real-Time Transport ProtocolSAToP Structure-Agnostic Time Division Multiplexing over PacketSCR Sustainable Cell Rate

SDH Synchronous Digital HierarchySDU Service Data Unit

SNAP Subnetwork Access ProtocolSNMP Simple Network Management ProtocolSONET Synchronous Optical Network

S-PE Switching PESS-PWE3 Single-Segment PWE3TDM Time Division MultiplexingTLV Type Length Value

T-PE Terminating PETS0 Timeslot zeroUBR Unspecified Bit RateUDP User Datagram ProtocolUMTS Universal Mobile Telecommunications System

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UNI User Network InterfaceVBR Variable Bit Rate

VC Virtual CircuitVCC Virtual Channel ConnectionVCCV Virtual Channel Connection and VerificationVCG Virtual Circuit Group

VCI Virtual Channel IdentifierVCL Virtual Channel Link

VP Virtual PathVPC Virtual Path ConnectionVPI Virtual Path IdentifierVPL Virtual Path LinkVPN Virtual Private NetworkVRF VPN Routing and Forwarding

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Table of Contents

About This Manual 14

Objectives 14

Audience 14

8600 Smart Routers Technical Documentation 14

Interface Numbering Conventions 18

Document Conventions 18

Documentation Feedback 18

8600 Smart Routers Discontinued Products 19

1 Pseudowire Emulation Edge-to-Edge (PWE3) 20

1.1 Overview 20

1.1.1 Terminating Provider Edge (T-PE) 21

1.1.2 Switching Provider Edge (S-PE) 21

1.2 Virtual Circuit Connectivity Verification Overview 22

1.2.1 Control Channel Methods 22

1.2.2 Connectivity Verification 24

1.2.3 Multi-Segment PWE3 VCCV LSP Ping and Traceroute 25

1.3 PWE3 Types 26

1.3.1 ATM PWE3 Support 27

1.3.2 Frame Relay PWE3 Support 28

1.3.3 HDLC PWE3 Support 28

1.3.4 TDM PWE3 Support 29

1.4 PWE3 Counters 30

1.5 References 31

2 Pseudowire Redundancy 32

2.1 Overview 32

2.2 Supported Functionality 33

2.3 Limitations and Restrictions 35

2.4 Operation 35

2.4.1 Provisioning Redundancy Group 35

2.4.2 Switching Operation 35

2.4.3 Dynamically Provisioned PWE3 Redundancy 36

2.4.4 Statically Provisioned PWE3 Redundancy 36

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2.4.5 VCCV BFD 37

2.4.6 PWE3 Redundancy Counters 37

2.5 PWE3 Redundancy Considerations 37

2.5.1 Specific PWE3 Types 37

2.5.2 Multi-Layer Protection 38

2.5.3 Configuration Checklist 38

2.6 References 39

3 Single-Segment PWE3 Configuration Examples 40

3.1 Node Basic Settings 41

3.1.1 Node T-PE223 41

3.1.2 Node T-PE123 41

3.2 Trunk Interfaces Configuration 42

3.2.1 Node T-PE223 42

3.2.2 Node T-PE123 43

3.3 Static Provisioning 43

3.3.1 Node T-PE223 Configuration 43

3.4 Dynamic Provisioning 44

3.5 SS-PWE3 Provisioning Status 45

4 MS-PWE3 Configuration Examples 47

4.1 Node Basic Settings 47

4.1.1 Node T-PE194 48

4.1.2 Node T-PE116 48

4.1.3 Node S-PE135 49

4.2 Trunk Interfaces Configuration 49

4.2.1 Node T-PE194 49

4.2.2 Node T-PE116 50

4.2.3 Node S-PE135 50

4.2.4 Transit Node P150 51

4.3 MS-PWE3 Static Provisioning 52

4.3.3 Node S-PE135 Configuration 53

4.4 MS-PWE3 Dynamic Provisioning 54

4.4.3 Node S-PE135 Configuration 55

4.5 MS-PWE3 Provisioning Status 56

5 PWE3 Redundancy Configuration Examples 58

5.1 Redundancy Group 60

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5.2 T-PE Nodes Configuration 62

5.2.1 Node T-PE90 62

5.2.2 Node T-PE80 66

5.3 S-PE Nodes Configuration 69

5.3.1 Node S-PE76 69

5.3.2 Node S-PE79 71

5.4 Transit Nodes Configuration 73

5.4.1 NODE77 73

5.4.2 NODE78 73

5.5 Configuration Verification and Diagnostics 74

6 ATM Overview 78

6.1 Network Applications 78

6.1.1 Native ATM Switching Application 79

6.1.2 ATM PWE3 over MPLS Application 79

6.1.3 ADSL Application 80

6.1.4 SHDSL Application 85

6.1.5 ATM Aggregation to IP VPN Applications 86

6.2 IFM ATM Interfaces 88

6.3 ATM Interfaces 88

6.4 Generic ATM Functionality 89

6.4.1 Introduction 89

6.4.2 Mapping ATM to Framed Signals 90

6.4.3 ATM Transmission Convergence Layer 91

6.4.4 UNI and NNI Interfaces 91

6.4.5 ATM Switching 96

6.4.6 Traffic Management 97

6.4.7 IMA Functionality 102

6.4.8 IMA Split 105

6.4.9 ATM OAM Loopback 106

6.4.10 Preserving ATM QoS over MPLS 108

6.4.11 ATM Statistics Counters 108

6.5 ATM PWE3 Tunnelling 108

6.5.1 Introduction 108

6.5.2 N-to-1 PWE3 Mode over MPLS 109

6.5.3 N-to-1 PWE3 Mode over IP Connection 110

6.5.4 N-to-1 PWE3 and Address Translation 112

6.5.5 N-to-1 PWE3 with Cell Concatenation 114

6.5.6 1-to-1 PWE3 Mode 114

6.5.7 AAL5 SDU PWE3 Mode over MPLS 117

6.5.8 AAL5 SDU PWE3 Mode over IP Connection 119

6.6 Cell Concatenation Strategies 120

6.7 ATM Fault Management OAM (FM OAM) 121

6.7.1 ATM AIS 121

6.7.2 Inband ATM PWE3 OAM Message Mapping 121

6.7.3 Outband ATM PWE3 OAM Message Mapping 121

6.8 Protection Functionality 122

6.9 Limitations and Restrictions 122

6.10 References 123

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7 ATM Layer Configuration Examples 124

7.1 Configuring ATM Interface Layer (Transmission Convergence Layer) 124

7.2 Configuring ATM Interface Level Connection and Admission Control 125

7.3 Configuring NE-Level CAC 125

7.4 Configuring IMA Group in SDH/SONET MS IFM 126

7.5 Configuring IMA Split 127

7.6 Configuring IMA Group in PDH MS Interfaces 128

7.7 Configuring IMA Loopback 129

7.8 Configuring VP Cross-Connection in ATM IFM 129

7.9 Deleting VP Cross-Connection in ATM IFM 131

7.10 Configuring VC Cross-Connection in ATM IFM 132

7.11 Configuring VP Cross-Connection in SDH/SONET MS IFM 134

7.12 Configuring VC Cross-Connection in SDH/SONET MS IFM 135

7.13 Configuring VP Cross-Connection in PDH MS Interfaces 135

7.14 Configuring VC Cross-Connection in PDH MS Interfaces 135

7.15 Configuring IP over AAL5 Interface for Routing 135

7.16 Configuring ATM Circuit Using N-to-1 PWE3 over MPLS Network 136

7.17 Configuring ATM Circuit Using AAL5 SDU PWE3 over MPLS Network 138

7.18 Configuring ATM Cell Concatenation 140

7.19 Configuring ATM Egress Buffer Size 140

7.20 Configuring N-to-1 (N>1) ATM PWE3 and Address Translation 140

8 TDM Overview 143

8.1 Network Applications 143

8.1.1 Local TDM Cross-Connections 143

8.1.2 Mobile Access Backhaul 143

8.2 PWE3 Tunnelling 144

8.2.1 SAToP 144

8.2.2 CESoPSN 145

8.2.3 Packetization and Jitter Buffering 145

8.2.4 IP/UDP Encapsulation 147

8.2.5 Adaptive Jitter Buffering 147

8.2.6 Limitations and Restrictions 149

8.3 Pseudowire Synchronization 149

8.4 TDM Pseudowire OAM (L, M, R) 150

8.5 References 150

9 TDM Cross-Connection and Tunnelling Configuration Examples 151

9.1 Configuring Local T1 Cross-Connections 151

9.2 Configuring E1 SAToP Tunnelling over Wide Area IP/MPLS Network 153

9.3 Configuring NxDS0 CESoPSN Mobile Backhaul over Metro Ethernet with Adaptive Timing 155

9.4 Adaptive Jitter Buffer Configuration Examples 158

9.4.1 CESoPSN 158

9.4.2 SAToP 158

9.4.3 AJB Monitoring 159

9.5 Configuring TDM PWE3 over IP 161

9.6 TDM PWE3 OAM (L, M, R) Configuration 162

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9.6.1 TDM PWE3 Defect Forwarding 1629.6.2 TDM PWE3 Replacement Data 1629.6.3 TDM PWE3 Report 163

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About This Manual

This chapter discusses the objectives and intended audience of this manual, 8600 Smart Routers

ATM and TDM Configuration Guide and consists of the following sections:

functionality for administration personnel with a graphical user interface

It is assumed that the readers have a basic understanding of Ethernet, POS, IP, MPLS, IP VPN Thismanual also assumes that readers are familiar with the following protocols:

• IP routing

• UDP

• TCP

• Differentiated Services

8600 Smart Routers Technical Documentation

The document numbering scheme consists of the document ID, indicated by numbers, and thedocument revision, indicated by a letter The references in the Related Documentation table beloware generic and include only the document ID To make sure the references point to the latestavailable document versions, please refer to the relevant product document program on the Tellabsand Coriant Portal by navigating towww.portal.tellabs.com> Product Documentation & Software

> Data Networking > 8600 Smart Routers > Technical Documentation

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Document Title Description

8600 Smart RoutersATM and TDM Configuration Guide(76.8600-50110)

Provides an overview of 8600 NEs PWE3 applications,including types, Single-Segment and Multi-Segment; PWE3Redundancy; ATM applications, including PWE3 tunnelling,Traffic Management, Fault Management OAM, protection andTDM applications as well as instructions on how to configurethem with CLI

8600 Smart RoutersBoot and Mini-ApplicationsEmbedded Software Release Notes(76.8600-50108)

Provides information related to the boot and mini-applicationssoftware of 8605 Smart Router, 8607 Smart Router, 8609Smart Router, 8611 Smart Router, 8620 Smart Router, 8630Smart Router and 8660 Smart Router as well as the installationinstructions

8600 Smart RoutersCLI Commands Manual(76.8600-50117)

Provides commands available to configure, monitor and maintain

8600 system with CLI

8600 Smart RoutersEmbedded Software Release Notes

8600 Smart Routers SR7.0 Embedded Software Release Notes(76.8670-50177) for the following products:

Provides an overview of 8600 system HW inventory, softwaremanagement, equipment protection 1+1 (CDC and SCM) as well

as instructions on how to configure them with CLI

8600 Smart RoutersEthernet Configuration Guide (76

8600-50133)

Provides an overview of 8600 system Ethernet applications,including interfaces; Ethernet forwarding (MAC Switching,Ethernet PWE3, IRB, VLAN, VPLS); Ethernet OAM; LAG;ELP as well as instructions on how to configure them with CLI

8600 Smart Routers Smart RoutersFault Management ConfigurationGuide (76.8600-50115)

Provides an overview of 8600 system fault management,including fault source, types and status as well as instructions onhow to configure it with CLI

8600 Smart RoutersFrame Relay Configuration Guide(76.8600-50120)

Provides an overview of 8600 system Frame Relay applications,including interfaces; Performance Monitoring; protection; TrafficManagement as well as instructions on how to configure themwith CLI

8600 Smart RoutersHardware Installation Guide(76.8600-40039)

Provides guidance on mechanical installation, cooling,grounding, powering, cabling, maintenance, commissioning andESW downloading

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8600 Smart RoutersInterface Configuration Guides The Interface Configuration Guides provides an overview of the8600 NEs interface functions, including NE supported interface

types and equipping; interface features; configuration options andoperating modes; fault management; performance monitoring;interface configuration layers and port protocols as well asinstructions on how to configure them with CLI The followinginterface configuration guides are available:

• 8600 Smart Routers Network Interfaces ConfigurationGuide (76.8600-50161) (for 8602 Smart Router, 8615 SmartRouter and 8665 Smart Router)

• 8609 Smart Router and 8611 Smart Router FP7.0 InterfaceConfiguration Guide (76.8670-50179)

• 8600 Smart Routers FP7.0 Interface Configuration Guide(76.8670-50180) (for 8630 Smart Router and 8660 SmartRouter)

8600 Smart Routers

IP Forwarding and TrafficManagement Configuration Guide(76.8600-50122)

Provides an overview of 8600 NEs IP, forwarding and trafficmanagement functionality, including: IP addressing; IP hosting(ARP, DHCP); IP routing (static); ACL; Differentiated Services(Policing, Queue Management, Shaping) as well as instructions

on how to configure them with CLI

8600 Smart RoutersManagement CommunicationsConfiguration Guide

(76.8600-50125)

Provides an overview of 8600 system managementcommunications functions, including communication protocols:BMP; FTP; RADIUS; SNMP; SSH; TELNET as well asinstructions for configuring them with CLI

8600 Smart RoutersMobile Optimization ConfigurationGuide (76.8600-50100)

Provides an overview of 8600 system Mobile Optimizationapplications as well as instructions on how to configure themwith CLI

8600 Smart RoutersMPLS Applications ConfigurationGuide (76.8600-50123)

Provides an overview of 8600 NEs MPLS applications (includingFRR (one-to-one and facility backup); LDP; protection andTraffic Engineering), MPLS-TP applications (including OAM,linear protection), S-MPLS applications as well as instructions

on how to configure them with CLI

8600 Smart RoutersPerformance Counters ReferenceGuide (76.8600-50143)

Provides an overview of 8600 system supported performancecounters

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8600 Smart RoutersReference Manuals The reference manuals describe the 8600 network elementfeatures including:

• NE enclosure, baseboard, power supply modules, andinterfaces in 8602 Smart Router FP7.0 Reference Manual(76.8670-40130)

• NE enclosure, baseboard, power supply modules, interfacesand physical LM types in 8609 Smart Router FP7.0 Refer-ence Manual

• NE enclosure, baseboard, power supply modules, SCMs, HMand LM types in 8611 Smart Router FP7.0 Reference Manual

• NE enclosure, baseboard, power supply modules, and terfaces in 8615 Smart Router FP7.0 Reference Manual(76.8670-40132)

in-• NE subrack, fan modules, CDCs, line cards and IFMs in 8630Smart Router FP7.0 Reference Manual

• NE subrack, fan modules, CDCs, line cards and IFMs in 8660Smart Router FP7.0 Reference Manual

• NE subrack, fan modules, line unit and switch unit in 8665Smart Router FP7.0 Reference Manual (76.8670-40128)

8600 Smart RoutersRouting Protocols ConfigurationGuide (76.8600-50121)

Provides an overview of 8600 NEs routing protocols, includingBFD; BGP; BGP MP; ECMP; IS-IS; OSPF and VRRP as well asinstructions on how to configure them with CLI

8600 Smart RoutersScalability Reference Manual(76.8600-50160)

Provide a summary of tested scalability limits of the 8600 SmartRouters

8600 Smart RoutersSNMP MIB Support(76.8600-50116)

Describes SNMP MIB support by the 8600 NEs and providesinformation on the supported objects and traps For furtherinformation on SNMP MIBs, see the related RFCs

8600 Smart RoutersStatistic Counters Reference Guide(76.8600-50142)

Provides an overview of 8600 system supported statistic counters

8600 Smart RoutersSynchronization ConfigurationGuide (76.8600-50114)

Provides an overview of 8600 NEs synchronization functionality,including physical layer Frequency Synchronization (SEC, EEC);PTP Frequency Synchronization; Phase-Time Synchronization(L2 and L3 applications) as well as instructions on how toconfigure them with CLI

8600 Smart RoutersTest and Measurement ConfigurationGuide (76.8600-50124)

Provides an overview of 8600 NEs measurement and connectivityverification tools, including Ethernet loopback; IP ping andtraceroute; MAC swap loopback; MPLS ping and traceroute;PLT; PWE3 loopback; VCCV (BFD, LSP ping) as well asinstructions on how to configure them with CLI

8600 Smart RoutersVPNs Configuration Guide(76.8600-50128)

Provides an overview of 8600 system virtual private network(VPN) layer 3 applications as well as instructions on how toconfigure them with CLI

8000 Intelligent Network ManagerOnline Help Provides instructions on how different operations are performedwith the 8000 Intelligent Network Manager Describes also

different parameters and controls of the 8000 Intelligent NetworkManager dialogs and windows

Note that the Online Help is not available on the Portal but it isincorporated in the 8000 Intelligent Network Manager

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Interface Numbering Conventions

To be able to follow more easily the feature descriptions and configuration examples given in this

document, see also the 8600 system interface numbering and related figures described in 8600

Smart Routers CLI Commands Manual.

Document Conventions

This is a note symbol It emphasizes or supplements information in the document.

This is a caution symbol It indicates that damage to equipment is possible if the instructions are not followed.

This is a warning symbol It indicates that bodily injury is possible if the instructions are not followed.

Documentation Feedback

Please contact us to suggest improvements or to report errors in our documentation:

Email: fi-documentation@tellabs.com

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8600 Smart Routers Discontinued Products

8600 Smart Routers Manufacture Discontinued (MD) notifications are available on the Tellabsand Coriant Portal,www.portal.tellabs.com > Product Documentation & Software > Data Networking > [8600 Smart Router product name] > Product Notifications.

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1 Pseudowire Emulation Edge-to-Edge (PWE3)

Pseudowire Emulation Edge-to-Edge (PWE3) is a technology defined in [RFC3985] that providesmechanisms to emulate network services such as ATM, TDM, Ethernet over a Packet-SwitchedNetwork (PSN) A PWE3 emulates a point-to-point and provides a single service over an underlyingIP/MPLS core network The ability of providing a single service over a PSN is the main advantage

of PWE3 technology and the key point for services convergence in an MPLS network

From connectivity stand point PWE3 can be classified as follows:

• Single-Segment PWE3 (SS-PWE3)

• Multi-Segment PWE3 (MS-PWE3)SS-PWE3 spans a single PSN, e.g RSVP-TE tunnel and provides point-to-point connectivitybetween PWE3 end points, i.e the originating and Terminating Provider Edges (T-PE) in the samePSN domain or PWE3 control plane domain as illustrated in the following figure

Fig 1 SS-PWE3

MS-PWE3 defined in [RFC6073] spans through multiple PSN tunnels (also known as domains), i.e

it consists of two or more segments that are interconnected via Switching Provider Edge (S-PE)between two PWE3 T-PEs in the different packet switched network domains or PWE3 control planedomains as illustrated in the following figure

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Fig 2 MS-PWE3

1.1.1 Terminating Provider Edge (T-PE)

The 8600 NEs support both static and dynamic provisioning of PWE3 in T-PE Static provisionedpseudowires do not have any control plane protocol and are manually configured, whereas dynamicprovisioned pseudowires utilize LDP for signaling as defined in [RFC4447]

VCCV BFD can be used to provide continuos fault detection and propagation In this case, PWE3failure is detected by loss of specified number of consecutive BFD packets These protocols may

be used to test and monitor the actual data path of the PWE3 They can be used for both staticallyconfigured and signalled pseudowires, as well as MS-PWE3

PWE3 setup and maintenance using the Label Distribution Protocol LDP [RFC4447] defines twomethods for signaling of PWE3 status and both methods are supported by the 8600 NEs:

• Use of label withdraw messages (a.k.a label withdraw pseudowire status method)

• Use of PWE3 status TLV

1.1.2 Switching Provider Edge (S-PE)

In 8600 NEs, the following S-PE features are supported:

• Allows merging of PSN tunnels regardless of their type, which increases network scalability due

to reduced number of RSVP-TE tunnels

• PWE3 manual switching between two static control planes

• PWE3 switching between two dynamic (LDP) control planes

• VCCV control channel methods:

• Type 1: PWE3 control word with 0001b as the first nibble

• Type 3 (MPLS PWE3 Label with TTL = = 1) Control Channel (CC)

• VCCV protocols:

• end-to-end VCCV LSP traceroute reports switching pointsPWE3 status signaling methods:

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• Label withdraw messages

• PWE3 status TLVMS-PWE3 signaling between the end points is provided in the context of both T-PEs (edge-to-edge)and S-PEs (hop-by-hop), and includes the coordination of parameters related to each S-PE, aswell as the T-PE The PWE3 segments at S-PEs may be statically provisioned or they may besignalled dynamically using LDP protocol, but both segments must use the same method, i.e.static-dynamic conversion is not supported for PWE3 control plane From T-PE point of view there

is not a significant difference between SS-PWE3 and MS-PWE3 as S-PE acts transparently andmostly, just relays on control plane messages between the segments

In addition to PWE3 segment signaling, a switching function is required to interconnect thesegments at S-PEs Typically data packets contain two labels, both of which are changed at S-PE.The outer label belongs to the PSN tunnel that the segment utilizes, and the inner label is specific tothe PWE3 itself In this case the switching operation is characterized as “outer label pop, inner labelswap and outer label push”

In 8600 NEs, MS-PWE3 connectivity verification of the data path is supported at S-PE using VCCVtype 1 and type 3 control channels

1.2 Virtual Circuit Connectivity Verification Overview

Virtual Circuit Connectivity Verification (VCCV) is the IETF Operation, Administration andMaintenance (OAM) method for Pseudowire Emulation Edge-to-Edge (PWE3) circuits and isspecified in [draft-ietf-pwe3-vccv], [RFC5085] and [draft-ietf-pwe3-oam-msg-map] VCCV is

a method for providing control channel that is associated with a pseudowire, as well as a way

to inject OAM packets within PWE3 data stream so that these control packets can be captured

at PWE3 egress

1.2.1 Control Channel Methods

There are four possible Control Channel (CC) types defined for MPLS PWE3:

• Type 1: PWE3 control word with 0001b as first nibble (PW-ACH, see [RFC4385]) pwe3-vccv]

[draft-ietf-• Type 2: MPLS Router Alert Label [draft-ietf-pwe3-vccv]

• Type 3: MPLS pseudowire Label with TTL = 1 [draft-ietf-pwe3-vccv]

• Type 4: MH-VCCV Control Word [RFC6073]

Control channel support in 8600 NEs, varies depending on the interface types In general, a Type 1control channel is supported in multiservice interfaces, while a Type 3 is predominantly supported

on Ethernet interfaces The following table provides an outline of the supported functionality

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CC Types Support in the 8600 NEs

Multiservice(PDH)

8605 SmartRouter

Multiservice(PDH)

8607 SmartRouter

Multiservice(PDH)

8609 SmartRouter

Multiservice(PDH)

8611 SmartRouter

8615 SmartRouter

Multiservice(IFMs)

8620 SmartRouter

Ethernet(IFMs)

Multiservice(IFC line cardIFMs)1

Ethernet(IFC1 linecard IFMs)

Ethernet(IFC2 linecard IFMs)

8630 SmartRouter

8660 SmartRouter

Ethernet(ELC1)

8665 SmartRouter Ethernet(LU1)

1 In IFC line card with the 24xchE1/chT1 MS IFM, ETHo(ML)PPP PWE3 does not support CC type 3.

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• BFD for pseudowire fault detection only.

• BFD for pseudowire fault detection and Attachment Circuit (AC) or pseudowire Fault StatusSignaling

• BFD for pseudowire fault detection only Carrying BFD payload without IP headers

• BFD for pseudowire fault detection and AC or pseudowire Fault Status Signaling Carrying BFDpayload without IP headers

The 8600 NEs support LSP ping and all BFD variants

VCCV BFD

VCCV BFD works by sending continuously packets over PWE3 circuit PWE3 or Packet SwitchedNetwork (PSN) tunnel failure is detected by loss of specified number of consecutive BFD packets.VCCV BFD can also transmit status code indicating status of AC associated with PWE3 circuit.VCCV BFD is suitable for continuous connectivity verification of pseudowires But note that BFD

is not suitable for ad-hoc testing BFD monitoring is enabled for lifetime of the PWE3 circuitand enabling or disabling BFD involves re-signaling PWE3 circuit that can cause sub-secondinterruption to the services

The implementation of VCCV BFD is network processor based, and BFD can be used with smallfailure detection time-outs without adverse effect to CPU load

The usage of BFD ensures that PWE3 can forward data end-to-end and if such is not the case, afault is raised If the AC technology supports widely implemented OAM, native fault indication

is generated The 8600 NEs support generation of ATM AIS/RDI when VCCV detects PWE3failure or remote AC error

BFD variants without status signaling should be used with LDP provisioned pseudowires, as ACstatus signaling is provided by LDP With statically provisioned pseudowires BFD variants withfault signaling capability should be used, as VCCV BFD will then signal remote AC status forstatic pseudowires

Using IPv4 header containing BFD variant adds 28 bytes of overhead for each BFD packet androughly doubles the bandwidth usage

BFD variants without IPv4 header can be used only when control-word is used for PWE3.

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VCCV BFD failure detection timers should be selected in such manner that the underlyingprotection mechanisms have sufficient time to function, otherwise VCCV BFD is able to detectfailures handled by MSP, ELP and LSP 1:1 protection mechanisms, which would simultaneouslycause multi-layers detection triggering The following are some recommendations of possiblefailure detection timers for different protection scenarios:

• The default detection timer of 900 ms (with 300 ms transmission interval) should be able to vive most reroutes and protection mechanisms

sur-• If only MSP protection is used (and <50 ms reroute is guaranteed), PWE3 layer failure detectioncould be reasonably configured to use 100 ms detection interval with 33 ms hellos

• If no protection mechanisms are used, even a 1 ms transmission interval with 3 ms failure tion could be utilized

detec-• If low bandwidth PWE3 circuit monitoring is desired (and VCCV BFD is not used as a trigger

of PWE3 layer protection mechanisms), once a second or once in 10 seconds are reasonableintervals

Whenever possible, VCCV should be used Using VCCV ensures with a high degree of confidencethat any PWE3 circuit that does not have faults is fully operational and can forward data WithoutVCCV, PWE3 status is purely based on signaling information

In 8611 Smart Router when PWE3 are provisioned with VCCV BFD, packet loss can be observed during SCM switchover due to BFD states that are not synchronized between the active and passive SCMs.

VCCV LSP Ping

VCCV LSP ping can be used to verify PWE3 circuit connectivity on-demand Although VCCVLSP ping packets are generated by the control processor plane, they are inserted to a PWE3 circuitvery near of the actual attachment circuit and removed from data stream just before they would betransmitted towards to the other attachment circuit This guarantees extensive coverage for PWE3testing (as good as VCCV BFD)

Unlike VCCV BFD packets, VCCV LSP ping packets carry PWE3 identification that allows adetection of misconnections between PWE3 circuits Usually, PWE3 circuit name is used for LSPping However, if the PWE3 circuit is a local cross-connection with two interfaces, also an interfacename can be used for LSP ping allowing bidirectional testing

1.2.3 Multi-Segment PWE3 VCCV LSP Ping and Traceroute

The 8600 NEs support Multi-Segment Pseudowire (MS-PWE3) as defined in [RFC6073] AMS-PWE3 consists of two or more segments that are interconnected via a Switching Provider Edge(S-PE) between two PWE3 Terminating Provider Edge (T-PE)

VCCV LSP ping or traceroute for MS-PWE3 can be originated only from PWE3 T-PE VCCV LSP ping or traceroute for MS-PWE3 originated from S-PE is not supported.

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MS-PWE3 VCCV LSP Ping

If a PWE3 is segmented, VCCV LSP ping sending node must be aware of the attributes of the lastsegment prior to the target node The default values of these attributes correspond to the segmentthat is closest to the remote T-PE The 8600 NEs communicate these attributes via the LDP protocol

In a case the S-PE does not support communication of the segment attributes via LDP, or LDP is notused, or if there is a need to override the default values, the attributes can be configured manually

MS-PWE3 VCCV Traceroute

VCCV LSP traceroute can be used to verify connectivity over one or more PWE3 switching points(S-PE) The sending node tests each switching point along the data path by sending MPLS echorequests iteratively until the endpoint is reached This allows the sending node to automaticallylearn the next target Forwarding Equivalence Class (FEC) stack from each MPLS echo reply

• ATM AAL5 PDU

• ATM AAL5 SDU

2 Ethernet PWE3 [RFC4448] (please refer to 8600 Smart Routers Ethernet Configuration Guide)

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1.3.1 ATM PWE3 Support

Attachment Circuit Physical Trunk Interface NE

All interfaces ATM PWE3 over

MPLS

8605 SmartRouter

chE1/chT1 ATM

Ethernet interfaces ATM PWE3 over

IPAll interfaces ATM PWE3 over

MPLS

8607 Smart

Ethernet interfacesonly

ATM PWE3 overIP

MPLS

8609 SmartRouter

chE1/chT1 ATM

ATM PWE3 overIP

MPLS

8611 Smart

ATM PWE3 overIP

All MS, POS &

Ethernet IFMs

ATM PWE3 overMPLS

8620 SmartRouter

1/chOC-3 MSIFM

1xchSTM-1/chOC-3 MSIFM

4xchSTM-24xchE1/chT1

MS IFM

1/OC-3 ATMIFM

4xSTM-ATM

All EthernetIFMs except the2x1000BASE-XIFM

ATM PWE3 overIP

All MS, POS &

Ethernet IFMs andELC1 interfaces

ATM PWE3 overMPLS

8630 SmartRouter

8660 SmartRouter

1/chOC-3 MSIFM

MS IFM

1/OC-3 ATMIFM

4xSTM-ATM

All EthernetIFMs except the2x1000BASE-XIFM and ELC1interfaces

ATM PWE3 overIP

ATM PWE3 and the options supported are detailed covered in6.5 ATM PWE3 Tunnelling

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1.3.2 Frame Relay PWE3 Support

8620 SmartRouter

1/chOC-3 MSIFM

8630 SmartRouter

8660 SmartRouter

1/chOC-3 MSIFM

MS IFM

Frame Relay All MS, POS &

FR PWE3 overMPLS

Frame Relay PWE3 and the options supported are covered in 8600 Smart Routers Frame Relay

Configuration Guide.

1.3.3 HDLC PWE3 Support

All interfaces HDLC PWE3 over

MPLS

8605 SmartRouter chE1/chT1

HDLC

HDLC PWE3 overIP

MPLS

8607 Smart

Ethernet interfacesonly HDLC PWE3 overIPAll interfaces HDLC PWE3 over

MPLS

8609 SmartRouter chE1/chT1

HDLC

HDLC PWE3 overIP

MPLS

8611 Smart

Ethernet interfacesonly HDLC PWE3 overIP

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All MS, POS &

Ethernet IFMs HDLC PWE3 overMPLS

8620 SmartRouter

1/chOC-3 MSIFM

MS IFM

HDLC

All EthernetIFMs except2x1000BASE-XIFM

HDLC PWE3 overIP

All MS, POS &

HDLC PWE3 overMPLS

8630 SmartRouter

8660 SmartRouter

1/chOC-3 MSIFM

MS IFM

HDLC

HDLC PWE3 overIP

1.3.4 TDM PWE3 Support

Interface Tunnelling Interface Encapsulation

All interfaces SAToP PWE3 over

MPLSCESoPSN PWE3over MPLS

8605 SmartRouter

chE1/chT1 SAToP

CESoPSN

SAToP PWE3 overIP

CESoPSN PWE3over IP

8607 SmartRouter chE1/chT1 SAToPCESoPSN

SAToP PWE3 overIP

CESoPSN PWE3over IP

8609 SmartRouter

chE1/chT1 SAToP

CESoPSN

SAToP PWE3 overIP

CESoPSN PWE3over IP

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Interface Tunnelling Interface Encapsulation

8611 SmartRouter chE1/chT1 SAToPCESoPSN

SAToP PWE3 overIP

CESoPSN PWE3over IP

All MS, POS &

Ethernet IFMs

SAToP PWE3 overMPLS

CESoPSN PWE3over MPLS

SAToPCESoPSN

SAToP PWE3 overIP

CESoPSN PWE3over IP

8620 SmartRouter

1/chOC-3 MSIFM

MS IFM

CESoPSN overUDP over IP All EthernetIFMs except

2x1000BASE-XIFM

CESoPSN PWE3over IP

All MS, POS &

SAToP PWE3 overMPLS

CESoPSN PWE3over MPLS

SAToPCESoPSN

SAToP PWE3 overIP

CESoPSN PWE3over IP

8630 SmartRouter

8660 SmartRouter

1/chOC-3 MSIFM

MS IFM

CESoPSN overUDP over IP

CESoPSN PWE3over IP

TDM PWE3 and the options supported are detailed covered in8 TDM Overview

The 8600 NEs support PWE3 statistics, performance and Simple Network Management Protocol(SNMP) counters The counters are available via CLI or 8000 Intelligent Network Manager and theuser has the option to reset the counters, e.g before starting the tests

Please refer to 8600 Smart Routers Statistics Counters Reference Guide and 8600 Smart Routers

Performance Counters Reference Guide for a detailed list of supported counters Also refer to

8600 Smart Routers SNMP MIB Support for a complete list of PWE3 counters available via the

SNMP management interface

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1.5 References

msg-map] draft-ietf-pwe3-oam-msg-map-8.txt (2008–11) Pseudowire OAM MessageMapping[draft-ietf-pwe3-vccv] draft-ietf-pwe3-vccv-bfd-07.txt (2009–07) Bidirectional Forwarding

[draft-ietf-pwe3-oam-Detection (BFD) for the Pseudowire Virtual Circuit Connectivity Verification(VCCV)

[RFC3985] RFC3985 ( 2005–03), Pseudo Wire Emulation Edge-to-Edge (PWE3)

Architecture[RFC4379] RFC4379 (2006-02), Detecting Multi-Protocol Label Switched (MPLS) Data

Plane Failures[RFC4385] RFC4385 (2006–02) Pseudowire Emulation Edge-to-Edge (PWE3) Control

Word for Use over an MPLS PSN[RFC4447] RFC4447 (2006–04), Pseudowire Setup and Maintenance Using the Label

Distribution Protocol (LDP)[RFC4448] RFC4448.txt (2006-04), Encapsulation Methods for Transport of Ethernet

over MPLS networks[RFC5085] RFC5085 (2007–12) Pseudowire Virtual Circuit Connectivity Verification

(VCCV): A Control Channel for Pseudowires[RFC6073] RFC6073 (2011–01), Segmented Pseudowire

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2 Pseudowire Redundancy

This chapter provides a generic functionality description of pseudowire redundancy (also referred asPWE3 redundancy) in the 8600 NEs The supported functionality is highlighted in2.2 SupportedFunctionality.While the specific deviations per module type and PWE3 technology types are listed

in2.3 Limitations and Restrictions.The 8600 NEs support pseudowire redundancy to provide resiliency for Single-Segment andMulti-Segment pseudowire services against PSN failures This feature is especially targeted forsingle-homed Customer Equipment (CE) with MS-PWE3 redundancy topology option defined in[draft-ietf-pwe3-redundancy] Typically, protection for single-segment pseudowires is provided atthe PSN tunnel layer (e.g RSVP-TE path protection) However, in multi-AS networks MS-PWE3have one or more S-PEs that must be traversed The S-PEs for a given FEC128 based MS-PWE3are selected at provisioning phase and hence form a single point of failure If any of the S-PEstransited by the MS-PWE3 goes down, so does the MS-PWE3 Therefore, the PSN tunnel protectionmechanisms are unable to provide protection against S-PE failure PWE3 redundancy solves thisproblem by allowing several PWE3 layer paths to be provisioned end-to-end and hence removing asingle point of failure in the intervening network

PWE3 redundancy can also be used without the PSN layer protection (even for protectingsingle-segment pseudowires) and with VCCV BFD end-to-end OAM protection times, it can bemuch faster than with the PSN layer protection However, as OAM flows are per PWE3, it is moreeconomical to utilize PSN layer protection mechanisms for link and LSR and PWE3 redundancy forS-PE protection In this scenario VCCV BFD should be configured to such a rate and timeout thatPSN layer protection is fast enough not to trigger PWE3 layer protection

In PWE3 redundancy, a redundancy group is formed by one primary PWE3 and up to threeprotecting pseudowires The redundancy group is associated to one attachment circuit If theprimary PWE3 fails, the system will select one of the active protecting pseudowires Only onepseudowire is forwarding user traffic at a time, but OAM traffic is allowed to be forwarded over thestandby pseudowires

The following terminology is used in this section:

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PWE3 State Description

Active PWE3 The PWE3 forwarding traffic An active PWE3 can be the primary or one of

the aliases

Standby PWE3 An alias PWE3 that is operational and ready to forward traffic in case the active

PWE3 fails

Down A state of the primary or alias PWE3 when there is a severe PWE3 failure

Up A state of the primary or alias PWE3 when it is operational ready to forward

data

Fig 3 PWE3 Redundancy Application

This chapter provides a generic overview of PWE3 redundancy supported functionality:

• Single-segment and multi-segment PWE3 However, for SS-PWE3, redundancy is not mended because LSP protection provides, e.g better scalability

recom-• Dynamically (LDP) and statically provisioned pseudowires

• Up to 3 alias pseudowires A selection of the active PWE3 is made, if several aliases are available

• Independent path selection mode and Preferential Forwarding Status bit (LDP) redundancy-bit]

[draft-ietf-pwe3-• BFD over VCCV type 1 monitoring for fast failure detection per primary and alias pseudowiresfor ATM and TDM pseudowires

• BFD over VCCV type 3 monitoring for fast failure detection per primary and alias pseudowiresfor Ethernet PWE3

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• 8600 NEs proprietary prefer-all mode, which does not signal LDP bit to accelerate theswitchover.

• Statistics and performance counters for the active PWE3

• PWE3 loopback is supported per primary and alias pseudowires when VCCV BFD is not ured

config-The following tables provide a detailed support of PWE3 redundancy in 8600 NEs config-The notation

“—” used below stands for not supported

ATM and TDM PWE3 Redundancy Support in 8620 Smart Router, 8630 Smart Router and

8660 Smart Router

ATM and MS IFMs PWE3 Types

4xSTM-1/OC-3 ATM 4xchSTM- 1/chOC-3 MS 24xchE1/chT1 MS

ATM N-to-1(N=1)

ATM N-to-1(N>=1)

ATM and TDM PWE3 Redundancy Support in 8605 Smart Router, 8609 Smart Router and

8611 Smart Router

8605 Smart Router 8609 Smart Router &

8611 Smart Router PWE3 Types

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2.3 Limitations and Restrictions

This chapter provides an outline of the following limitations and restrictions with PWE3 redundancy

• PWE3 redundancy is not available in 8607 Smart Router

• For all PWE3 types the following functionality is not supported:

• MPLS over IP encapsulation

• Multi-homed CE topology for protected ATM or TDM attachment circuit

• Manual switchover and non-revertive mode

• Master/slave mode

• Remote switchover and PWE3 Request Switchover Status code

• Hold-time timer to provide hysteresis

• For ATM and TDM PWE3 redundancy, the following functionality is not supported:

• Local dual-homing

• ANSI mode

2.4.1 Provisioning Redundancy Group

A pseudowire redundancy group consists of one primary PWE3 and up to three alias (protecting)pseudowires A redundancy group is set up automatically when the first alias PWE3 is associated tothe primary PWE3 and the group will be removed after the last alias is removed When a redundancygroup is created, it is operational immediately and no explicit redundancy operation enabling isrequired The primary PWE3 must be configured before aliases and the configuration order ofthe three aliases is irrelevant From the MPLS point of view aliases are standard pseudowireswith their own signaling and state mechanisms Each redundancy group operates independently

of the other groups

2.4.2 Switching Operation

PWE3 redundancy operates in 1:1 or 1:N fashion At the MPLS ingress direction traffic is forwardedonly via one active pseudowire while the other pseudowires are on standby state If several standbyaliases are available, the selection of the active path is done in the priority order described belowseparately for dynamically and statically provisioned pseudowires The switchover is revertive, i.e.immediately and the traffic is switched back to the primary PWE3 when it is up again There is nohold-timetimer to delay the switching back

At the MPLS egress direction traffic is summed from all pseudowires and sent to the Native ServiceProcessing (NSP) to regenerate the native signal to the attachment circuit

A source trigger for switchover can be:

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• Locally detected PSN link layer failure,

• PSN connectivity (LSP) failure,

• VCCV BFD connectivity failure,

• Any failure reported by LDP

The switchover is executed group by group, thus the switchover time grows linearly as proportion ofthe number of redundancy groups

2.4.3 Dynamically Provisioned PWE3 Redundancy

Dynamically provisioned PWE3 redundancy utilizes LDP to inform the remote-end T-PE, whichPWE3 is currently selected as active and is forwarding user traffic This state information is known

as preferential forwarding state The 8600 NEs also support a proprietary option (prefer-all) toadvertise the preferential state for all standby pseudowires to speed up the switchover

When the option prefer-all is set, each end of the PWE3 in the T-PE selects a fault-free PWE3

as the forwarding PWE3 In case of multiple fault-free pseudowires, the order of selection goes asfollows: primary, alias 1, alias 2, alias 3 As both T-PEs should have an identical view of PWE3faults, priority should be configured identically in both T-PEs, otherwise PWE3 redundancy willnot operate properly

When the option prefer-all is not used, each T-PE performs two slightly different processes:

Step 1 Selecting the PWE3 that is advertised as active, while the other pseudowires remain in standby

state This selection is made purely on the basis of known faults The standby information from

a remote T-PE is ignored

Step 2 Selecting an active PWE3 All fault information, including remote standby (preferential forwarding

status) is used The standby bit advertised by the local node is not used directly However, if theselected PWE3 is not the one selected as the active in step 1, then in effect no PWE3 is active.The remote standby bit does not affect local standby bit advertisement, as otherwise signalingoscillations could occur In the case of single-homed MS-PWE3, the only advantage of usingstandby bit is that LDP is able to tell that the remote T-PE has correctly selected the active PWE3.This advantage is however offset by increased protection switch time, as the standby bit has to bepropagated over TCP connection between non-real time processes In the prefer-all mode,VCCV triggered protection can be performed with real time processes and hence the protectionswitch is faster

The standby bit offers additional functionality on multi-homed applications, such as Multi-ChassisAPS (MC-APS) Interworking with multi-homing remote T-PE (other than the 8600 NE) is fullysupported In such cases, the standard behavior of single-homed T-PE advertising active status onall pseudowires can be accomplished by configuring the prefer-all option While the 8600NEs do not currently support MC-APS or full-blown multi-homed end of protected PWE3, they canfully participate in such role as a single-homed end In this case, MC-APS (or other multi-homingprotocol) drives the active PWE3 selection on the 8600 NE and the standby bit plays a significantrole in it

2.4.4 Statically Provisioned PWE3 Redundancy

The operation of statically provisioned PWE3 redundancy is identical to the dynamicallyprovisioned PWE3 redundancy (see2.4.3 Dynamically Provisioned PWE3 Redundancy), with theonly exception that the preferential forwarding state is not signalled

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2.4.5 VCCV BFD

VCCV BFD can be used to monitor the health of the primary and of each alias PWE3 between theT-PEs for both SS-PWE3 and MS-PWE3 If faster switchover time is required, the PSN can detectfailures VCCV BFD is essential for MS-PWE3 to protect it against PSN failures If an S-PE acting

as a stitching node between two segments totally fails, then the T-PEs and their redundancy groupsmay not be informed immediately of the failure in the S-PE node

In the case of dynamically provisioned PWE3, a failure is recognized later as loss of the target LDPpeer or loss of LSP connectivity, which may take up to tenth of seconds to recover In the case ofstatic provisioned PWE3, a failure is recognized as loss of LSP connectivity

2.4.6 PWE3 Redundancy Counters

PWE3 redundancy supports the same statistics, performance and SNMP counters that are availablefor not protected pseudowires (see1.4 PWE3 Counters) PWE3 circuit counters are supported forthe primary and all alias pseudowires separately The attachment circuit counters are available onlyfor the redundancy group and are derived from the current active PWE3

2.5.1 Specific PWE3 Types

The 8600 system implementation follows the PWE3 redundancy group architecture defined in[draft-ietf-pwe3-redundancy] A PWE3 instance is multiplied according to the number of aliases.There is only one NSP instance per redundancy group, which is associated only to the active PWE3.The following PWE3 technology specific items are highlighted:

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• CESoPSN and SAToP PWE3:

• Attachment circuit side failures are not used as a switchover trigger

• Inband TDM OAM signaling (AIS and RDI):

• AIS in TDM ingress interface is connected only to the active PWE3 AIS (all ones)packets received only from an active PWE3 will force AIS insertion to the TDM egressinterface

• L-bit and R-bit insertion is performed only to an active PWE3 L-bit and R-bit ceived only from an active PWE3 (not from the standby pseudowires) forces AIS andRDI insertion to the TDM egress interface

re-• Outband Pseudowire Status Signaling:

• Attachment Circuit Forward defect; near-end physical interface defect (LOS, AIS,LOF) state of the attachment circuit is mapped to the active and standby pseudowires

to be signalled via LDP to the remote end Respectively the received forward defectmessage only in the active PWE3 forces AIS insertion to the TDM egress interface

• Attachment Circuit Reverse defect; far-end physical interface defect (RDI) of the tachment circuit is mapped to the active and standby pseudowires to be signalled viaLDP to the remote end Analogously, the received reverse defect message only in ac-tive PWE3 forces RDI insertion to the TDM egress interface

at-• There is only one logical jitter buffer per redundancy group

• ATM PWE3:

• Attachment circuit side failures are not used as a switchover trigger

• Inband TDM OAM signaling:

• Local physical interface failure (LOS, AIS, LOF) forces an active and standby dowires to be pulled down

pseu-• If all pseudowires are down the AIS is generated to TDM egress interface

• Outband Pseudowire Status Signaling:

• Attachment Circuit Forward defect; near-end physical interface defect (LOS, AIS,LOF) state of the attachment circuit is mapped to the active and standby pseudowires

to be signalled via LDP to remote end Analogously the received forward defect sage only in active PWE3 forces AIS insertion to the ATM attachment circuit

mes-• ATM ping can be send only to the active PWE3 and not to the standby pseudowires Onlythe active PWE3 replies to ping request (loopback reply)

2.5.2 Multi-Layer Protection

PWE3 redundancy creates an additional protection layer on top of the LSP protection layer Anoperator needs to carefully design the coordination between LDP and RSVP trunk protection orrestoration and PWE3 redundancy to achieve an optimum switchover time and to avoid unnecessaryflapping of the different protection schemes

2.5.3 Configuration Checklist

To avoid most potential pitfalls in the PWE3 redundancy configuration, below is a list of the items

to check and consider during the planning and configuration of the network:

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• If several protection mechanisms like RSVP path protection or Fast Reroute (FRR) are used currently, check in which order the layers should trigger to a failure and configure the timersaccordingly.

con-• Check that forcing PWE3 to working and protecting MPLS trunks operates as planned

redundancy] draft-ietf-pwe3-redundancy-08.txt (2012–05), Pseudowire Redundancy[draft-ietf-pwe3-

[draft-ietf-pwe3-redundancy-bit] draft-ietf-pwe3-redundancy-bit-05.txt (2011–09), Pseudowire PreferentialForwarding Status Bit

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3 Single-Segment PWE3 Configuration

Examples

In the 8600 system, PWE3 circuit can be signalled as follows:

• Static inner label / static outer label

• Static inner label / dynamic outer label (RSVP)

• Static inner label / dynamic outer label (LDP)

• Dynamic inner label (LDP) / dynamic outer label (RSVP)

• Dynamic inner label (LDP) / dynamic outer label (LDP)

Fig 4 SS-PWE3 Configuration Topology

The main focus in this section is on the CLI commands required for establishing PWE3 connectivity.Therefore, it is worth to be noted that a configuration of the MPLS and related routing protocols is

not completely covered in this example For additional details refer to 8600 Smart Routers MPLS

Applications Configuration Guide and 8600 Smart Routers Routing Protocols Configuration Guide.

For a complete range of options available within PWE3 commands refer to 8600 Smart Routers CLI

Commands Manual The details of the interface physical layer configuration are covered in the 8600 Smart Routers Interface Configuration Guides.

To set up PWE3 services, at least the following tasks are required:

• Node basic settings

• Trunk interfaces configuration

• Provisioning PWE3 services

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