NSE and PSE on SONET interface

Question;

Hi,

I saw NSE and PSE counts are increasing big time on our SONET interface. My Cisco has 1 OC12 POS controller with 12.2 IOS.
I could ignor the event if fews per days, but it is a lot.

WestRouter#sh controllers pos 1/0
POS1/0
SECTION
LOF = 0          LOS    = 0                            BIP(B1) = 0
LINE
AIS = 0          RDI    = 0          FEBE = 0          BIP(B2) = 0
PATH
AIS = 0          RDI    = 0          FEBE = 0          BIP(B3) = 0
LOP = 0          NEWPTR = 0          PSE  = 11877      NSE     =12577

Any advice would be appreciate.

we set clocking source "line" on both (ISP said that they set clocking source "line")

 

Answer:

In general, NSE and PSE would be due to clocking source issue. Have you check both interfaces are set to "line".
Unless your SONET is connected to both routers in back to back, clocking source will be provided by SONET Ring.
Best way is to work with telco, and test to loops stepping out from our router since that is where we are seeing the issue.

Check the below link to get more info.
http://www.cisco.com/en/US/tech/tk482/tk607/technologies_tech_note09186a008009464b.shtml

That’s good.
From what I’ve seen in the past on your interface, you will not see any impact to traffic unless the PSE/NSE’s are updating by the thousands every second. The Cisco web page advises that a stratum 3 timed-device allows for up to 59.6 stuffs per second.

The NSE & PSE only indicate that the payload has shifted within the SONET frame. This does not impact customer data.

Check this one out for more information for a decent explanation of stuff events.
http://www.cisco.com/en/US/partner/tech/tk482/tk607/technologies_tech_note09186a008009464b.shtml

PSE and NSE counters will be increased below conditions

– The received signal is very degraded.
– There are sufficient differences in the accuracy of the oscillator at each end
– The physical fiber is not clean
– The transmitter is overdriving the remote receiver and there is insufficient attenuation on the link
– Errored condition 

Per Cisco, Cisco router is not generated PSE and NSE event.