802.1ag - Connectivity Fault Management Tutorial – Part 1 Dinesh Mohan July 12, 2004

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] ag PAR Overview

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] 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”

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] 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”

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] 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

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 5 OAM Framework

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 6 Ethernet OAM Layering CEU-PE N-PE CEBBPPPP Device View Ethernet Layer Eth AccessMPLS CoreMPLS Access Customer Service Provider Example: network/service with Ethernet & other technologies The Ethernet Layer implies the visibility to Ethernet frames –BUT Flat! Difficult to manage and identify accountability

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 7 OAM Domain – Service/Network Eth AccessMPLS CoreMPLS Access Customer Service Provider Customer Domain Provider Domain Operator Domain Solution: OAM Domains Domains necessary to bound OAM Flows & OAM responsibilities

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 8 Maintenance Entity Points (MEP) & Maintenance Intermediate Points (MIP) Network OAM Service OAM Customer Domain Provider Domain Operator Domain Eth AccessMPLS CoreMPLS Access Customer Service Provider MPLS Domain Maintenance Entity Point Maintenance Intermediate Point PW/MPLS OAM MEPs initiate/terminate/react to all OAM flows MIPs react to some OAM flows [Optional] MEPs & MIPs dependent on Business Models & Deployment Scenarios

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 9 Ethernet MEPs & MIPs Customer Equipment Operator A Bridges Operator B Bridges ETH ETY Another representation for positioning of MEPs and MIPs on devices with consideration for ingress and egress. Maintenance Entity Point Maintenance Intermediate Point

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 10 Maintenance Entities Mapped Example MEs identified –2 Service Providers (SP1 & SP2) –SP2 has two domains (operators) –MEs 1,2,3,4 are required for Business relationship –MEs 5,6 are required for convenience Customer Service Provider 1. UNI_C-UNI_C ME 2. UNI_N-UNI_N ME 3. UNI ME SP 1SP 2 4. E-NNI ME 5. Inter-domain ME (SP) 6. Intra-domain ME 6. Intra-domain ME (Operator) UNI E-NNI

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 11 End-to-end OAM – 2 Models Provider End-to-end OAM? CE-CE (terminating UNIs) –2 Possible Models  Strong-Trust E-NNI ME (3) + ME (2) + ME (3)  Weak-Trust E-NNI ME (3) + ME (6) + ME (4) + ME (5) + ME(3) or ME (3) + ME (6) + ME (4) + ME (6) + ME(3) Customer Service Provider 1. UNI_C-UNI_C ME 2. UNI_N-UNI_N ME 3. UNI ME SP 1SP 2 4. E-NNI ME 5. Inter-domain ME (SP) 6. Intra-domain ME 6. Intra-domain ME (Operator) UNI E-NNI

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 12 Maintenance Entities – P2P Case All MEs may not be needed always MEPs realize Maintenance Entities (MEs)

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 13 Maintenance Entities – MP2MP Case All MEs may not be needed always MEPs realize Maintenance Entities (MEs)

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 14 Maintenance Entities – CPE based Network Demarcation Access All MEs may not be needed always ETH_FP Service. Provider Y Network Operator B User X UNI_C to UNI_C ME UNI_N to UNI_N ME Access Link ME ETH_TFP ETH_FP User X Access Link ME Extension Link ME User Location UNI_NP to UNI_NP ME UNI ETH_FP ETH Link Private NNI ETH_FP Network Operator A ETH Link NNI ETH_FP ETH FPP Link UNI ETH FPP Link ETH_TFP ETH_FP NDD

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 15 Maintenance Entities – CPE based Network Demarcation Access All MEs may not be needed always

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 16 Service/Network OAM – How does it come together? Ethernet link OAM PW/MPLS OAM EoSONET OAM Other OAM Network OAM Service OAM Transport Links Network Services OAM Interworking possible to utilize OAM across Layers However, each layer must support OAM capabilities independently

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 17 Connectivity Fault Management Functions

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 18 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

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 19 Other OAM Functionality (out of scope for.1ag) 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

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 20 CFM Functions mapped to MEs Customer Service Provider 1. a, b, c 2. a, b, c Note: Specifically for ME (3) and ME (4) –IEEE 802.3ah 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 3. a, b, c, e SP 1SP 2 3. a, b, c 4. a, b, c 5. a, b, c 6. a, b, c

802.1ag – Connectivity Fault Management Tutorial – Part 1 (Jul 12, 2004) [Dinesh Mohan] - 21 Summary Ethernet moving into Provider Networks Providers require fault management tools to manage their networks High Industry interest in Ethernet connectivity fault management tools