6608 T1/PRI Total Rx RTP Lost Pkts

[f.kirstein]

We've seen some noise issues on calls on our CUCM. 

We have 3 PRI/T1 with our service provide Paetec.  And 2 PRI and 1 T1 set up between our Rolm 9751 and CUCM. 

All PRI/T1 have high numbers of Total Rx RPT lost pkts (over 4 billions each) when looking at device status.  Occasionally I can catch a Total Rx RPT lost pkts on specific ports when looking at the PORT status, but mostly these run clean.  As usage increases on a PRI, the rate of lost pkts increases too.

1.  Is there a way to clear the device Total RX RPT lost pkts counts?

2.  Is there a correlation between the Device Total RX RPT lost pkts and the noisy calls we're hearing?

3.  Where do I look to resolve this.

I do not see errors on the Rolm 9751 side of the PRI's.

Thank you.

Frank Kirstein

Kirstein@Canisius.edu

[acampbell]

Frank,

6608 getting old now.

Your problem is probably due to poor "CLOCKIN" configuration,

Hopefully your ROLM 9751 is attached somewhere to the PSTN/ISDN network and sould be deriving its clock from the there.

So if you select your PSTN links to clock from "NETWORK"  then clock the ROLM links from "SPAN 1 to 8" so that they are synched with the PSTN links , basically all clocks should be locked as one.

Hopefully this will stop your received errors

HTH

Alex

[f.kirstein]

Thank you Alex.  I'll change the clocking source and see what I end up with. 

[f.kirstein]

Hi Alex,

It took awhile, but I now have all the PRIs set to 1 clock source.  Paetec to our Rolm 9751 T1 to Span 7 on the 6608.  All the PRI on the CCM from Paetec and internally get the clock from Span 7.  Traffic looked clean for about 2 hours, than 1 Lost Pkt followed by 246 lost packets, and finally, 4 billion.  I actually caught a Port status which shows port 22 with RTP Sent Pkts of 318, RTP Rcvd pkts of 318 and Lost RX pkts of 4294901760.   All of our PRI/T1 show lost pkts of over 4 billion. 

Any ideas?

Thanks all.