PSM protect path is in alarm

[Roman Rodichev]

Hi, I'm using PSM to protect path between two 15454 nodes. Attached are the readings on the PSM ports on two sides. Any idea why the protect path is in alarm even though it's getting -25 and -28 dB on two sides? I confirmed that the protect TX sources are correct and not coming from some other source. The threshold settings are set to values below -32 dB. Also, do you recommend attenuating?

[supoonia]

Hi Roman,

What alarm you are observing on these P-Rx ports, also check for conditions.

also what are optical thresholds values for warning and alarms.

go to card view -- provisioning - optical line - optics threshold - click on alarm -- refresh

go to card view -- provisioning - optical line - optics threshold - click on warning -- refresh

[Roman Rodichev]

Ah, beautiful, thank you, I forgot to hit refresh when switching to Alarm. P-RX was set to incorrect value (20db). I changed on both sides to -43, applied, sync'ed, and alarm is gone.

if you don't mind can I ask you a couple more questions about PSM?

1. Do you recommend configuring VOA attenuation for P-RX in my case?

2. My OPT-AMP-17C (booster mode) shows SPANLEN-OUT-OF-RANGE minor alarm condition on LINE RX port (connected to PSM COM TX) on both nodes. Just as an example on one side, COM TX reads -19.7 db, OPT-AMP-17C LINE RX reads -42 db (no channels in use just yet) and -19.7 db for OSC. See screenshot for this side's readings, and warning/alarm thresholds. It looks like alarm thresholds look good.

3. and the last question is about PSM's behavior. If W is cut, it fails over to P. If W is restored, I believe it remains on P because it's non-revertive. I have to manually fail it over to W. The question is what happens if W is restored but I forget to revert to W from P, and P is cut. Will it revert to W or will my network be down?

[supoonia · Accepted solution]

1. We have VOA before Com-Tx and two VOAs before W-Tx and P-Tx

http://www.cisco.com/en/US/docs/optical/15000r9_2/dwdm/reference/guide/454d92_optproswcard.html

I think current levels on P-Rx are ok, if you don't have any errors on your traffic cards.

also please note that siwtching is based on alarm threshold, so to reach -43 threhsold there should be a complete fiber cut, and switching will happen at that time only.

if there will be a degarde in optical power level, switching will not happen. you can decrease VOA for Com-Tx to improve power levels.

2. SPAN-Length out of range is there because of increase/decrease in span loss in respect to max/min span loss threshold.

go to node view --- maintenance - DWDM - WDM span check -- retrieve span loss values -- check min/max span loss and mesaured corresponding to that.

3. even if we forgot to revert, it will behave in same manner, when the power level decreases belore threshold at P, it will raise a alarm and PSM will switch.

also please feel free to reach for more clarifications.