Alcatel-Lucent 7710 SR OS, Interface Configuration Manual

Page: 93 / 436

Interface Configuration
7710 SR OS Interface Configuration Guide Page 93
Remote Loopback
EFM OAM provides a link-layer frame loopback mode that can be remotely controlled.
To initiate remote loopback, the local EFM OAM client sends a loopback control OAM PDU by
enabling the OAM remote-loopback command. After receiving the loopback control OAM PDU,
the remote OAM client puts the remote port into local loopback mode.
To exit remote loopback, the local EFM OAM client sends a loopback control OAM PDU by
disabling the OAM remote-loopback command. After receiving the loopback control OAM PDU,
the remote OAM client puts the port back into normal forwarding mode.
Note that during remote loopback test operation, all frames except EFM OAM PDUs are dropped
at the local port for the receive direction, where remote loopback is enabled. If local loopback is
enabled, then all frames except EFM OAM PDUs are dropped at the local port for both the receive
and transmit directions. This behavior may result in many protocols (such as STP or LAG)
resetting their state machines.
Note that when a port is in loopback mode, service mirroring will not work if the port is a mirror-
source or a mirror-destination.
802.3ah OAM PDU Tunneling for Epipe Service
The 7710 routers support 802.3ah. Customers who subscribe to Epipe service treat the Epipe as a
wire, so they demand the ability to run 802.3ah between their devices which are located at each
end of the Epipe.
Note: This feature only applies to port-based Epipe SAPs because 802.3ah runs at port level not
VLAN level. Hence, such ports must be configured as null encapsulated SAPs.
When OAM PDU tunneling is enabled, 802.3ah OAM PDUs received at one end of an Epipe are
forwarded through the Epipe. 802.3ah can run between devices that are located at each end of the
Epipe. When OAM PDU tunneling is disabled (by default), OAM PDUs are dropped or processed
locally according to the
efm-oam configuration ( shutdown or no shutdown ).
Note that by enabling 802.3ah for a specific port and enabling OAM PDU tunneling for the same
port are mutually exclusive. Enforcement is performed on the CLI level.