MPLS-TP OAM based on Y.1731

Italo Busi (Editor)

Huub van Helvoort (Editor)

Jia He (Editor)

Current contributors

• Christian Addeo (Alcatel-Lucent), Simon Delord (Telstra), John Hoffmans (KPN), Ruiquan Jing (China Telecom), Wang Lei (CMCC), Han Li (CMCC), Vishwas Manral (IPInfusion), Julien Meuric (France Telecom), Masahiko Mizutani (Hitachi), Philippe Niger (France Telecom), Manuel Paul (Deutsche Telekom), Josef Roese (Deutsche Telekom), Vincenzo Sestito (Alcatel-Lucent), Nurit Sprecher (Nokia Siemens Networks), Yaakov Stein (RAD), Yuji Tochio (Fujitsu), Munefumi Tsurusawa (KDDI R&D Labs), Maarten Vissers (Huawei), Yaacov Weingarten (Nokia Siemens Networks)

Pro-active CC-V and RDI (CCM)

• MEP-to-MEP• Unique Source MEP Identifier for pro-active CV

– MEG_ID uses a TLV-like structure allowing extensibility

– Current MEP_ID definition (from Y.1731) fully meets ITU-T transport requirements

• The label identifies the transport path being monitored– Allows identification of which transport path is affected

by the misconnection and take appropriate consequent actions

Pro-active CC-V and RDI (CCM) – 2

• Very lightweight protocol behavior– Transmission period is constant (unless reconfigured)

• PDUs are always sent at the configured rate

• Determinism and predictability in the protocol behavior

• In transport networks, NMS configures and fully controls the rate for pro-active CC-V

– LOS detection multiplier is a standard constant

– Defect detection as per OAM Framework

– No need for additional status information other than the configuration parameters and defect states

On-demand CV Function (LB)

• MEP-to-MEP

• MEP-to-MIP with TTL expiry– Open issue regarding the encoding of the

Target MIP identifier

• Support node-based MIP

• Support ingress and egress MIPs– Simplify fault localization within the network

On-demand CV Function (LB) – 2

• Lightweight protocol behavior– Targeted node just reply copying the received

packet

• Data TLV allows testing MTU of the transport path

Note – The same procedures, with a Test TLV, are used to perform bidirectional diagnostic test (in-service or out-of-service)

AIS

• Server MEP to MEP• Lightweight protocol behavior

– AIS packets transmitted every second during server failure conditions

– Receiving MEP suppresses LOC reporting as soon as the first AIS packet arrives

• Behavior compatible with persistency filters for alarm reporting used in transport networks

– LOC reporting suppression removed if AIS not received for 3.5 seconds

Packet Delay Measurement (DM)

• MEP-to-MEP• One-way and two-way delay measurements• Can run on-demand or pro-actively• Simple protocol

– Insert the timestamp values at transmission/reception time

– Just calculate differences– Two-way delays does not need time synchronization– Two-way delays excludes the time needed to create and

send the DM reply back

Packet Loss Measurement (LM)

• MEP-to-MEP• Can run on-demand or pro-actively• Simple protocol

– Insert the transmitted/received packet counters at transmission/reception time

– Just calculate differences– No need for synchronization (neither for the counters

nor for the reference time) between MEP Source and Sink points

– Independent from network’s packet delay variation

Conclusion

• Y.1731 toolset provides the benchmark for OAM capabilities in packet transport networks– Functionality– Lightweight high protocol performance– Operational simplicity

• Expect same level of functionality, protocol performance and operational simplicity for MPLS-TP OAM

• Two possibilities– Defining tools that are functionally equivalent– Encapsulating Y.1731 OAM PDU