1 Nortel Confidential Information

MPLS & Ethernet OAM Interworking (draft-mohan-pwe3-mpls-eth-oam-iwk)

L2VPN WG, IETF-71 (Philadelphia)Mar 13, 2008

Dinesh Mohan (Nortel)Nabil Bitar (Verizon)

Philippe Niger (France Telecom)Simon Delord (Uecomm)

2

Overview

• This draft is targeted for PWE3 and is FYI for L2VPN WG• Since related to Ethernet VPWS service type

• draft-ietf-pwe3-oam-msg-map provides mapping of defect states between PW and associated AC • However, Ethernet AC not covered in the draft since Ethernet

OAM was work in progress at the time

• This draft specifies the mapping of defect states between Ethernet AC and associated Ethernet PW• IEEE 802.1ag and ITU-T Y.1731 activities have now been

completed, therefore, this activity is timely.

3

Reference Model

• Ethernet ACs do not necessarily have to be a physical link between CE and PE

• CE is not necessarily an end customer device, rather is a device in client network connecting to PSN for emulated service

4

Forward and Reverse Defects

• PE1 may detect forward defect in local Ethernet AC via one of:• AIS alarm generated by CE1• Failure in local link on which AC is configured• Failure to receive CCMs if local MEP is configured on the AC

• PE1 may detect forward defect in PW via one of:• Forward defect indication received from PE2• Unavailability of PSN path in PW domain to PE2

5

Forward and Reverse Defects (cont’d)

• PE1 may be notified of reverse defect in local Ethernet AC via:• CCMs with RDI bit set when MEP is configured on the AC

• PE1 may be notified of PW reverse defect via:• Reverse defect indication from PE2

6

PW Status and Defect Notification Options

• Use of Native Service Fault Notification• Ethernet PW currently do not specify native service fault notifications• However, if a MEP is created on PE associated with Ethernet PW, native

service notification options include:• AIS frames sent by MEP to peer MEP on other PE (convey forward defect)• Suspension of CCM frames (convey forward defect)• RDI bit in CCM frames (convey reverse defect)

• Use of PW Status Notification (for MPLS PSNs)• Forward defect: logical OR of local AC (ingress) receive fault AND local PW

(egress) transmit fault• Reverse defect: logical OR of local AC (egress) transmit fault AND local PW

(ingress) receive fault

• Use of BFD Diagnostic Codes• When using VCCV

• CV type of 0x04 used to indicate BFD for PW fault detection only and notification is carried out via Status Notification

• CV type of 0x08 used to indicate BFD for both PW fault detection and AC/PW fault notification, only BFD is used for fault notifications

7

Ethernet AC & PW Defect States Interworking (1)

• PW Forward Defect States Interworking (entry)• PE1 ability to receive user traffic from CE2 is impacted• Notify CE1

• If MEP is configured on AC, CCM not turned ON, send AIS• If MEP is configured on AC, CCM turned ON without Interface Status TLV

support, stop sending CCM• If MEP is configured on AC, CCM turned ON with Interface Status TLV support,

reflect state in Interface Status TLV• Notify PE2

• Via Native Service OAM mechanisms, if supported on PE for PW; ELSE• Via PW status notification or via VCCV-BFD diagnostic code (if CV type of 0x08

negotiated)• If forward defect entered via loss of control adjacency, no action is needed

• PW Forward Defect States Interworking (exit)• Reverse of the above steps

8

Ethernet AC & PW Defect States Interworking (2)

• PW Reverse Defect States Interworking (entry)• PE1 ability to transmit user traffic to CE2 is impacted• Notify CE1

• If MEP is configured on AC, CCM turned ON, set RDI bit in CCMs

• PW Reverse Defect States Interworking (exit)• Reverse of the above steps

9

Ethernet AC & PW Defect States Interworking (3)

• AC Forward Defect States Interworking (entry)• PE1 ability to receive user traffic from CE1 is impacted• Notify PE2

• Via Native Service OAM mechanisms, if supported on PE for PW; ELSE• Via PW status notification or via VCCV-BFD diagnostic code (if CV type of 0x08

negotiated)

• Notify CE1• If MEP is configured on AC, CCM turned ON, set RDI bit in CCMs

• AC Forward Defect States Interworking (exit)• Reverse of the above steps

10

Ethernet AC & PW Defect States Interworking (4)

• AC Reverse Defect States Interworking (entry)• PE1 ability to transmit user traffic to CE1 is impacted• Notify PE2

• Via Native Service OAM mechanisms, if supported on PE for PW; ELSE• Via PW status notification or via VCCV-BFD diagnostic code (if CV type of 0x08

negotiated)

• AC Reverse Defect States Interworking (exit)• Reverse of the above steps

11

Next Steps

• Already agreed in PWE3 WG that this draft would be pursued as a standalone document with references to draft-ietf-pwe3-oam-msg-map

• Work is mostly complete, therefore, target to pursue it as a PWE3 WG draft

• No significant concerns/objections expressed• Incorporate feedback/comments from interested parties