Cisco IOS Wide-Area Networking Configuration Guide - Free Books

Configuring OAM Local Emulation for ATM AAL5 over L2TPv3If a PE router does not support the transport of OAM cells across an L2TPv3 session, you can use OAMcell emulation to locally terminate or loopback the OAM cells. You configure OAM cell emulation onboth PE routers. You use the oam-ac emulation-enable command on both PE routers to enable OAMcell emulation.After you enable OAM cell emulation on a router, you can configure and manage the ATM VC in thesame manner as you would a terminated VC. A VC that has been configured with OAM cell emulationcan send loopback cells at configured intervals toward the local CE router. The endpoint can be either ofthe following:• End-to-end loopback, which sends OAM cells to the local CE router.• Segment loopback, which responds to OAM cells to a device along the path between the PE and CErouters.The OAM cells have the following information cells:• Alarm indication signal (AIS)• Remote defect indication (RDI)These cells identify and report defects along a VC. When a physical link or interface failure occurs,intermediate nodes insert OAM AIS cells into all the downstream devices affected by the failure. Whena router receives an AIS cell, it marks the ATM VC as down and sends an RDI cell to let the remote endknow about the failure.Beginning in Cisco IOS Release 12.0(30)S, you may choose to configure the OAM Local Emulation forATM AAL5 over L2TPv3 feature in ATM VC configuration mode or in VC class configuration mode.To enable the OAM Local Emulation for ATM AAL5 over L2TPv3 feature, perform one of the followingtasks:• Configuring OAM Local Emulation for ATM AAL5 over L2TPv3 in ATM VC Configuration Mode,page 78• Configuring OAM Local Emulation for ATM AAL5 over L2TPv3 in VC Class Configuration Mode,page 80Configuring OAM Local Emulation for ATM AAL5 over L2TPv3 in ATM VC Configuration ModeSUMMARY STEPSPerform this task to enable the OAM Local Emulation for ATM AAL5 over L2TPv3 feature in ATM VCconfiguration mode.1. enable2. configure terminal3. interface type slot/port4. pvc [name] vpi/vci [l2transport]5. encapsulation aal56. xconnect peer-ip-address vcid pw-class pw-class-name7. oam-ac emulation-enable [ais-rate]8. oam-pvc manage [frequency]78