Noise on IP Connections

[wattie29]

Have an odd problem fellas. Have two sites off one S8700. IP calls on a single site are fine but between sites and to the PSTN there is an audible clicking sound on the line every couple of seconds or so.

The only common feature is the 2Mb link between the sites, however I can't comprehend how noise can get into a digitised packet.

Any ideas?

Cheers

 

[moonearth]

Can use network monitoring tools to monitor the delay (if any) across the 2M link.

 

[VOIPeng]

Could be a Jitter issue, use the 90 day trial of the Avaya VOIP Monitoring Manager that comes with the Avaya Integrated Management Suite. It will allow you see the statistics for every call on a call by call basis for Jitter, Latency and Packet Loss. You can use this and make test calls to determine if QoS is an issue. If it is then you can use Network monitoring tools to pin down the issue. Another way of doing this is from SAT do a:
status station xxxx
for an active IP call and on page 5 you will see the statistics for the calls as well, however the VOIP Mon tool stores this information so you can search it for 30 days.

Hope this helps.

Thank you,
VOIPEng

 

[BuckWeet]

It kind of sounds like there is some packet loss. But the clicking that you are expeiriencing is usually timing issues in the voice world, which this could be totally true in this case too. What kind of routers do you have between the sites??

If they are cisco do a "sh contr e1 */*:*" Or it could also be a power issue on the carrier and noise is getting introduced into the system.. Very hard to say. I'd check the E1 link first to make sure it doesn't have any timing issues..


BuckWeet

 

[VOIPeng]

Sometimes a clipping sound can also be caused by Silence Suppression or the codec that you are using, do you have different Network Regions defined for these locations? Your Intranetwork region codec maybe what is causing the issue, or silence suppression.

These are quick thinks to look at and if you change them you will be able to tell immediately.

Thank you,
VOIPEng

 

[wattie29]

Thanks fellas, checked VoIP Mon, no packet loss or jitter. The E1 link is connected via Cajuns so hope no problem their. Did a packet sniff and after various test scenarios it appears the noise is originating on the TDM bus through the Medpros, I have escalated this to Avaya so I will let you know what the eventual outcome is.

 

[VOIPeng]

Check to see if silence suppression is enable on
'disp ip-codec-set #'

Thank you,
VOIPEng

 

[BuckWeet]

he said clicking not clipping, so its not silense suppression. I bet its a power issue on the carrier..

Do you have multiple carriers to where you could possibly move the board?

 

[wattie29]

Silence suppression is off and I have moved the board into the only other carrier. If I reset the Medpro though the problem disappears for about 4 hours. I have swapped the board and also upgraded to FW60.

 

[petran]

Hello,

A new firmware is available (fw 72). You can try it and see if it resolves the problem...

Petran.