Enhancements to Ethernet AIS David Elie Dit Cosaque, Kamakshi Sridhar, Maarten Vissers, Tony Van Kerckhove

IEEE July 11-16, 2004 — 2 Introduction > Proposals for essential EthAIS functions > EthAIS Coalescing > EthAIS accurate alarm suppression

IEEE July 11-16, 2004 — 3 Multiple lower level faults result in multiple EthAIS >Excessive bandwidth consumption Problem I: EthAIS cascading PE C CE CE C CE1 PE PE PE P CE2 P P Fault1 Fault2 Two EthAIS received

IEEE July 11-16, 2004 — 4 Benefits: >The bandwidth taken by EthAIS at each level is independent of the number of faults at lower levels >No change in AIS frame format required. Solution: EthAIS Coalescing > Solution: coalesce EthAIS in the MPs. Multiple faults at lower levels are seen as a single fault by higher levels Edge MP’s will generate a new AIS with a different sequence number.

IEEE July 11-16, 2004 — 5 Example: EthAIS coalescing PE C CE CE C CE1 PE PE PE P CE2 P P Fault1 Fault2 One EthAIS received LP MP Terminated Regenerated CCLoss Effectively solves the cascading problem without requiring AIS frame format change

IEEE July 11-16, 2004 — 6 Problem II: EthAIS Alarm suppression inaccuracies > Link failure alarms raised at server level, so CC loss alarm at any other level must be suppressed. > However, don’t want to suppress a CC loss due to customer fabric failure, because it is the only way to detect fabric faults. > A mechanism to selectively alarm fabric failure CCLoss needed C C CE1 PE PE PE P MP1 MP2 MP3MP CE CE4 Link Fault1 Fabric Fault2 MP4 CCLoss suppressed ME { MP5, MP1} CCLoss 1 ME { MP5, MP4} CCLoss 2 suppressed This must be alarmed ME { MP5, MP4} CCLoss 2

IEEE July 11-16, 2004 — 7 CCLoss suppressed CCLoss NOT suppressed Solution: TLV in AIS frame > EthAIS indicates which upper level MPs (MP1) are affected by a CCLoss > Stored in a data base at edge MP’s (Learning phase) > New TLV in EthAIS containing MP1 > MP suppress CCLoss from MEs indicated in the EthAIS TLV (AIS TLV phase) C CE C CE1 PE PE PE P MP1 MP2 MP3 MP1 MP5 CCLoss suppressed CE3 Link Fault1 Fabric Fault2 MP4 ME { MP5, MP1} CCLoss 1 ME { MP5, MP4} CCLoss 2

IEEE July 11-16, 2004 — 8 Implementation: EthAIS database > Indicates which customer MPs are behind provider MPs Provider MP Customer MPs behind it MP 2 MP 44 MP MP 24 MP EthAIS database in MP CE1 PE MP3

IEEE July 11-16, 2004 — 9 How is the TLV (MP1) generated for AIS? > MP1 is learnt from green CC. > MP1 is installed in blue CC to populate the EthAIS database in MP3 > Additional TLV in CC frames C CE CE C CE1 PE PE PE P CC MP1 CC MP1 CC MP1 Port 3 LP3 EthAIS database MP2 MP1-> MP3 CC MP1 LP2 CC Database MP1-> MP2 CC Port 2 TLV CC MP1 MP3 MP2

IEEE July 11-16, 2004 — 10 Summary +We propose: +a new Ethernet Coalescing scheme. +One AIS generated for multiple lower level faults. +a scheme for EthAIS accurate alarm suppression. +Allows for CC loss due to fabric failures to be alarmed, inspite of EthAIS. +EthAIS indicates unreachable upper level end point MP’s +We propose: +a new Ethernet Coalescing scheme. +One AIS generated for multiple lower level faults. +a scheme for EthAIS accurate alarm suppression. +Allows for CC loss due to fabric failures to be alarmed, inspite of EthAIS. +EthAIS indicates unreachable upper level end point MP’s

IEEE July 11-16, 2004 — 11