one-way-voice on PSTN

[ketanpatani]

I have two voice gateway 2811 and 2911,  I have only one E1 line.

When I am connecting E1 line on 2811 router we are not facing any issue, But when we connect that E1 line on 2911 router we are facing one way voice.Last week we upgrade the latest IOS on 2911 . The telecom service provider reset the e1 from there.

Not all the calls we are facing, Some calls are facing one way voice.

Attached the debug file.

[yahsiel2004 · Accepted solution]

Did you verify network connectivity on the 2911?

Yosh

[ketanpatani]

Both the voic gateway are same ip address, But e are connecting only one gateway.

Did you found in log about the network issue.

[Nishant Savalia]

Hi ketan,

One way voice is generally the issue of the slot/channel selection.

Please follow the process: -

1). As you have just one  E1, try to make random calls or ask the Telecom service provider to make some random calls.

2). Identify the call when you observe one way speech and ask the telecom guy on which slot/channel the call is landed.

3). If the slot/channel is different then you are done with your troubleshooting.

With mutual understanding, Two ends should match the slot/channel selection pattern, as below:

1) A Side (Odd slot selection) ------------ B Side (Even slot selection)

2) A Side (Sequential (1,2,3,4...) slot selection) ------------ B Side (Sequential (31,30,29,28... slot selection)

Also please let me know if there is any other device such as MUX is connected in between?

Regards,

Nishant