Fabric Led Behavior Is Different From Fps; Fabric Replacement Can Affect Traffic - Nortel Passport 15000 Hardware Description

104 Chapter 3 Shelf assembly

Fabric LED behavior is different from FPs

Fabric replacement can affect traffic
241-1501-200 5.2S2
For more information about the operation of fabrics, see the chapter on fabrics
in 241-5701-600 Passport 7400, 15000, 20000 Configuration Guide.
Passport 15000 fabrics are installed in opposite orientations relative to each
other (unlike Passport 20000). Orient installing a fabric by using the insertion
alignment arrows that are labeled onto each Passport 15000 fabric and the
middle of the shelf assembly. Passport 20000 fabrics are installed in the same
orientation relative to each other.
Since a red LED can be caused by more than disabling, a fabric with a red
LED can still be transmitting traffic. Similarly, a fabric with a green LED
might be prevented from transmitting traffic. To handle these unusual fabric
behaviors, and to prevent uncontrolled errors from hot-swapping an unlocked
fabric, always manually lock a fabric and allow time for the transfer of
connections before physically removing it from a shelf, and unlock it as soon
as a replacement is seated.
For the complete pattern of fabric LED behaviors, refer to"Status LEDs of a
fabric in a Passport 15000" (page 352) or "Status LEDs of a fabric in a
Passport 20000" (page 354).
When both fabrics of a Passport 15000 or 20000 are in service, they operate
in a load-sharing mode such that either fabric can take over all the traffic of
its mate. When a fabric fails completely, the failure triggers the remaining
fabric to take over the incoming load of the failed fabric and the failed failure
is put into a lock-out state. Traffic in progress is unavoidably lost during the
switchover.
When the system removes a fabric from service (disables it), it puts the fabric
in a lock-out state, but it does not automatically lock it in software. Prior to
removing a fabric from a shelf assembly, you must always manually lock the
fabric in software. (This is not the same as the lock-out state of a failed fabric.)
Locking the target fabric allows a takeover of traffic by its mate and prepares
the system to allow returning the replacement fabric to service. Without
manual locking, the system cannot put the replacement fabric into service.
Manually unlocking the fabric triggers the return to service, but the lock
command had to have been used first.