802 1 ag Connectivity Fault Management Tutorial Part

802. 1 ag - Connectivity Fault Management Tutorial – Part 1 Dinesh Mohan July 12, 2004

802. 1 ag PAR Overview 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 1

802. 1 ag Scope • “This standard specifies protocols, procedures, and managed objects to support transport fault management. These allow discovery and verification of the path, through bridges and LANs, taken for frames addressed to and from specified network users, detection, and isolation of a connectivity fault to a specific bridge or LAN” 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 2

802. 1 ag Purpose • “Bridges are increasingly used in networks operated by multiple independent organizations, each with restricted management access to each other’s equipment. This standard will provide capabilities for detecting, verifying and isolating connectivity failures in such networks” 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 3

802. 1 ag Reason for Standardization • Growing interest in the use of Fault Management tools within enterprise and provider networks • Such tool needed for established operational practices • Existence of similar tools e. g. – ATM’s “continuity check”, “Loopback” and “multiple Loopback” and – IP’s “ping” and “traceroute” • Interest and activities within ITU-T and MEF have further highlighted the need for these fault management tool 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 4

OAM Framework 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 5

Ethernet OAM Layering Customer Service Provider Customer Eth Access Device View CE U-PE B B MPLS Core N-PE P P MPLS Access P N-PE P U-PE CE Ethernet Layer • Example: network/service with Ethernet & other technologies • The Ethernet Layer implies the visibility to Ethernet frames – BUT Flat! Difficult to manage and identify accountability 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 6

OAM Domain – Service/Network Customer Service Provider Eth Access Customer MPLS Core MPLS Access Customer Domain Provider Domain Operator Domain • Solution: OAM Domains • Domains necessary to bound OAM Flows & OAM responsibilities 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 7

Maintenance Entity Points (MEP) & Maintenance Intermediate Points (MIP) Customer Service Provider Eth Access Customer MPLS Core MPLS Access Customer Domain Service OAM Provider Domain Operator Domain Maintenance Entity Point Maintenance Intermediate Point • • • Operator Domain MPLS Domain Network OAM PW/MPLS OAM MEPs initiate/terminate/react to all OAM flows MIPs react to some OAM flows [Optional] 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 8 MEPs & MIPs dependent on Business Models & Deployment Scenarios

Ethernet MEPs & MIPs Customer Equipment 1 Operator A Bridges 2 3 Operator B Bridges 4 5 6 7 Customer Equipment 8 9 ETH ETY Maintenance Entity Point Maintenance Intermediate Point • Another representation for positioning of MEPs and MIPs on devices with consideration for ingress and egress. 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 9

Maintenance Entities Mapped UNI Customer E-NNI UNI Service Provider Customer SP 1 3. UNI ME SP 2 1. UNI_C-UNI_C ME 2. UNI_N-UNI_N ME 4. E-NNI ME 3. UNI ME 5. Inter-domain ME (SP) 6. Intra-domain ME (Operator) 6. Intra-domain ME • Example MEs identified – – 2 Service Providers (SP 1 & SP 2) SP 2 has two domains (operators) MEs 1, 2, 3, 4 are required for Business relationship MEs 5, 6 are required for convenience 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 10

End-to-end OAM – 2 Models UNI Customer E-NNI UNI Service Provider SP 1 3. UNI ME Customer SP 2 1. UNI_C-UNI_C ME 2. UNI_N-UNI_N ME 4. E-NNI ME 3. UNI ME 5. Inter-domain ME (SP) 6. Intra-domain ME • 6. Intra-domain ME (Operator) 6. Intra-domain ME Provider End-to-end OAM? CE-CE (terminating UNIs) – 2 Possible Models Ø Strong-Trust E-NNI • ME (3) + ME (2) + ME (3) Ø Weak-Trust E-NNI • ME (3) + ME (6) + ME (4) + ME (5) + ME(3) or • ME (3) + ME (6) + ME (4) + MEFault (6)Management + ME(3) 802. 1 ag – Connectivity Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 11

Maintenance Entities – P 2 P Case • MEPs realize Maintenance Entities (MEs) • All MEs may not be needed always 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 12

Maintenance Entities – MP 2 MP Case • MEPs realize Maintenance Entities (MEs) • All MEs may not be needed always 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 13

Maintenance Entities – CPE based Network Demarcation Access User Location User X ETH FPP Link Network Operator A NDD ETH Link Service. Provider Y Network Operator B ETH Link ETH_TFP UNI ETH_FP Private ETH_FP NNI ETH FPP Link User X ETH_FPUNI ETH_TFP ETH_FP UNI_C to UNI_C ME UNI_N to UNI_N ME Extension Link ME UNI_NP to UNI_NP ME Access Link ME • All MEs may not be needed always 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 14

Maintenance Entities – CPE based Network Demarcation Access User Location User X ETH FPP Link Network Operator A NDD Service. Provider Y Network Operator B ETH Link ETH_TFP UNI ETH_FP Private ETH_FP NNI ETH FPP Link User X ETH_FPUNI ETH_TFP ETH_FP NDD 1 2 3 4 5 6 • All MEs may not be needed always 7 8 9 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 15

Service/Network OAM – How does it come together? Services Service OAM Network OAM Transport Links Ethernet link OAM PW/MPLS OAM Eo. SONET OAM Other OAM • OAM Interworking possible to utilize OAM across Layers • However, each layer must support OAM capabilities independently 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 16

Connectivity Fault Management Functions 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 17

CFM Functionality • a) CC – Continuity Check • • Multicast unidirectional heartbeat Use: Fault Detection • b) Loopback • • Unicast bi-directional request/response Use: Fault detection, verification • c) Traceroute • • Multicast request/unicast responses Use: Fault Isolation 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 18

Other OAM Functionality (out of scope for. 1 ag) • d) Discovery – i) Service • e. g. discover all PEs supporting common service instance – ii) Network • e. g. discover all devices (PE and P) common to a domain • e) AIS/RDI • Use: E<->W Fault propagation, Alarm Suppression • f) Performance Management 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 19

CFM Functions mapped to MEs Customer Service Provider SP 1 Customer SP 2 1. a, b, c 2. a, b, c 3. a, b, c, e 4. a, b, c 6. a, b, c 3. a, b, c 5. a, b, c 6. a, b, c • Note: Specifically for ME (3) and ME (4) – IEEE 802. 3 ah OAM can be used for network/link OAM when UNI/E-NNI is an Ethernet link – When single service carried across a link, network OAM can map to service OAM 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 20

Summary • Ethernet moving into Provider Networks • Providers require fault management tools to manage their networks • High Industry interest in Ethernet connectivity fault management tools 802. 1 ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 21