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Optical link instability leads to 10G XFP optical module tx fault alarm solutions

Publication Date:  2014-12-31 Views:  2328 Downloads:  0

Issue Description

Customer feedback a XFP optical module using a 10G interface device frequently reported TxFault alarm log information is as follows:
Jun 20 2014 16: 47: 44 + 08: 00 XXXX %% 01SRM / 2 / NODEFAULT (l) [619557]: Slot = 2; PIC0 of LPU 2 is failed, perhaps XFP0 TxFault of XFP0 is abnormal (Reason = ". Card0 Port0: PIC XFP TX FAULT ")!

Handling Process

1. TxFault optical module status is automatically detected by the XFP module inside and send it out via pin NR (NOT READY), software is responsible for the results of the display module detects and alarms.
 2.XFP MSA module according to the protocol described, NR state is taking or the result of three signals, the three signals are:
Laser Fault: namely, the light-emitting module fails, what we want to test TxFault.
3. Tx Loss of Lock: namely the transmit direction CDR loss of lock, this failure rarely encountered, usually resulting in a device or module failure.
4. Rx Loss of Lock: namely, the failure to accept the direction of the CDR, the optical signal is unstable when received, can not recover the clock signal, causes this loss of lock.
5. However, some manufacturers of modules are not strictly in accordance with the requirements of the MSA to achieve the NR. Finisar modules such as common, there is no Laser Fault signal. NR includes only the RX / TX Loss of Lock.
Others, such as JDSU, OPNEX, new fly-optical modules, etc., can be detected in real Laser Fault.

Root Cause

Troubleshoot existing network using Finisar module, which may be the only reported TxFault Rx Loss of Lock, so the recovery after the investigation and optical quality.


Check the quality of optical path.