Abstract

Link fault signaling (LFS) operates between the remote RS and the local RS. Faults detected between the remote RS and the local RS are received by the local RS as Local Fault. RS is the only layer that can generate Remote Fault signals. 

Sublayers within the PHY are capable of detecting faults that render a link unreliable for communication. Upon recognition of a fault condition, a PHY sublayer indicates Local Fault status on the data path. When this Local Fault status reaches an RS, the RS stops sending MAC data, and continuously generates a Remote Fault status on the transmit data path (possibly truncating a MAC frame being transmitted). When Remote Fault status is received by an RS, the RS stops sending MAC data, and continuously generates Idle control characters. When the RS no longer receives fault status messages, it returns to normal operation, sending MAC data.

The RS reports the fault status of the link. Local Fault indicates a fault detected on the receive data path between the remote RS and the local RS. Remote Fault indicates a fault on the transmit path between the local RS and the remote RS.

     The fault status is as follows:

a) link_fault = OK

                  The RS shall send MAC frames as requested through the PLS service interface. In the absence of MAC frames, the RS shall generate Idle control characters.

b) link_fault = Local Fault

                  The RS shall continuously generate Remote Fault Sequence ordered_sets.

c) link_fault = Remote Fault

                  The RS shall continuously generate Idle control characters.

Link Fault Signaling 

If ignore local fault is set as false: When link local fault is triggered, the RS shall continuously generate Remote Fault Sequence ordered_sets. Otherwise, the RS will not generate Remote Fault Sequence ordered_sets.

If ignore remote fault is set as false: When link remote fault is received, the RS shall continuously generate Idle control characters. Otherwise, the RS shall send MAC frames as requested through the PLS service interface and generate Idle control characters in the absence of MAC frames

LFS Commands

The following is the configuration command as sample:

set interface gigabit-ethernet te-1/1/1 link-fault-signaling ignore-local-fault true/false
set interface gigabit-ethernet te-1/1/1 link-fault-signaling ignore-remote-fault true/fals

Up Mode 

The force up command forcibly brings up a fiber Ethernet port and enables the port to forward packets unidirectionally over a single link. In this way, transmission links are well utilized.

Up Mode Commands

The following is the configuration commad as sample:

set interface gigabit-ethernet te-1/1/1 up-mode true/false