Ethernet OAM and Protection Ethernet OAM and Protection Switching - PowerPoint PPT Presentation

I nternational Telecom m unication Union ITU-T Ethernet OAM and Protection Ethernet OAM and Protection Switching Switching Hiroshi Ohta Senior Research Engineer, NTT I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6

W hy Ethernet becam e popular am ong carriers? ITU-T Reduced equipment costs o Ethernet as a universal interfacing o technology Can carry any protocol other than IP o Recent improvement of bridges o • High-speed IF (1G, 10G) • Long distance IF (-40km) • Advanced access capabilit ies (EFM) • More scalable bridges (802.1ad) ... however, OAM capability was limited. o I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 2

W hat are OAM ( Operation and Maintenance) functions? ITU-T o OAM functions include: • Defect detection • Defect information notification • Defect localization/ isolation • System protection • Performance management o ... without these capabilities, it is almost impossible to provide "carrier-class" services o OAM is a "must" for carriers I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 3

Recent standardization status ITU-T o ITU-T SG13 consented in Jan. 2006 meeting: • Y.1731 (Ethernet OAM) o ITU-T SG15 consented in Feb. 2006 meeting: • G.8031 (Ethernet protection) • G.8010 amendment 1 (Ethernet architecture) • G.8021 amendment 1 (Ethernet equipment) o IEEE 802.1ag (CFM): • Draft 6.1, Under WG ballot I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 4

Y.1 7 3 1 ( Ethernet OAM m echanism s) - 1 ITU-T o Y.1731 is a superset of IEEE 802.1ag o Both Y.1731 and IEEE 802.1ag specify • CC (Continuity Check): loss of connectivity defect detect ion • LB (Loopback): defect localization • LT (Link Trace): verification of network configuration I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 5

Y.1 7 3 1 ( Ethernet OAM m echanism s) - 2 ITU-T o Y.1731 also specifies: • Fault management —AIS (Alarm Indication S ignal): Alarm suppression —Test: throughput, frame loss and bit error measurement —LCK (Locked): indication of service unavailability due to maintenance activities —MCC (Maintenance Communication Channel) —EXP (Experimental OAM) —VS P (Vendor S pecific OAM) • Performance management —LM (Loss measurement): frame loss measurement —DM (Delay measurement): frame delay measurement I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 6

Y.1 7 3 1 vs. I EEE 8 0 2 .1 ag ITU-T o Same specifications (although the ways of description are different) • CC, LB, LT o OAM frame is identified by a specific EtherType. IEEE 802.1ag specifies this value. o Each OAM function is identified by the value of the "OpCode" field. • 32 code points are reserved for IEEE 802.1ag • Other 32 code points for ITU-T. I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 7

ITU-T OAM mechanisms I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 8

MEG levels ITU-T Multiple MEG levels are defined to allow running OAM in different spans I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 9

CC ( Continuity Check) - 1 ITU-T Customer Customer Operator A Operator A Operator B Operator B Customer Customer Equipment Equipment Bridges Bridges Bridges Bridges Equipment Equipment 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 CC frames ETH ETH ETH or ETH or SRV SRV MEP MIP • MEP transmits CC frames periodically. • If a MEP does not receive any CC frames for 3.5 times of the CC frame transmission interval, it declares an alarm (loss of connectivity) I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 0

CC ( Continuity Check) - 2 ITU-T Each receiving MEP Each MEP sends CC detects loss of CC frames frames to all other MEPs and unexpected CC frames MEP (MEG end point) MIP (MEG intermediate point) CC can be used for defect detection in multipoint-to-multipoint networks. I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 1

LB ( Loopback) ITU-T Operator Customer Customer Operator B Operator A Equipment Equipment 1 2 3 4 5 6 7 8 9 Case1) MEP to MEP ETH Case2) MEP to MIP - LB is mainly used for connectivity verification changing the test span. I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 2

LT ( Link Trace) Operator ITU-T Customer Customer Operator B Operator A Equipment Target Bridge Equipment 1 2 3 4 5 6 7 8 9 p1 p2 p1 p2 p1 p1 p2 p3 10 11 12 13 14 p1 p2 ETH - LT is mainly used for verifying the network configuration. I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 3

AI S ( Alarm I ndication Signal) ITU-T AIS is used for alarm suppression by notifying the bridges in downstream of the existence of the defect and of the fact that it has already been reported (and as such, bridges in downstream need to take no action). I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 4

Test signal Customer ITU-T Customer Equipment Equipment 1 2 3 4 5 6 7 8 9 ETH ETH or SRV Test signal generation Test signal detection/measurement • Supports in-service and out-of-service test • Defines Test OAM frames, which includes sequence number and PN pattern for frame loss and bit error measurement • Bidirectional Test frame uses the same OpCode as the LB (Loopback) OAM frame I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 5

G.8 0 3 1 ( Ethernet protection sw itching) ITU-T Defines bidirectional 1+1/ 1:1 and unidirectional 1+1 protection switching. o This version covers point-to-point protection switching only. o Protected ETH#A SNC Protected ETH#A SNC EAST EAST WEST WEST ETH#A (Normal Traffic) ETH#A (Normal Traffic) Working Transport Entity (for ETH#A) Working Transport Entity (for ETH#A) ETH#A (Normal Traffic) ETH#A (Normal Traffic) Protection Transport Entity (for ETH#A) Protection Transport Entity (for ETH#A) SNC SNC ETH_FF ETH_FF SNC SNC ETH_FF ETH_FF ETH_FP ETH_FP Protection Protection Protection Protection Switching Switching Switching Switching Process Process Process Process 1:1 bidirectional protection switching architecture I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 6

Conclusion ITU-T o Ethernet is now widely used by carriers. o Its OAM capabilities were limited but ITU-T consented Ethernet OAM and other related Draft Recommendations recently. o Recommendations on Ethernet architecture, Ethernet equipment and Ethernet services are also under work. These standards are expected to become available soon. o These Ethernet-related standards enhance advantages and attractiveness of Ethernet as a transport technology for NGN. I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 7