[asterisk-ss7] echo on a SS7/E1

[John Bigelow]

I suggest to also upgrade DAHDI to the latest version which contains 
newer firmware for the VPMADT032.

-John

Jean Cérien wrote:
>
> Hello
>
> I have the following setup:
>
> Ast1.6.1.18+Chan-SS7  1.3 --> TE221 Board + VPMADT032 hw echo 
> canceller  --> E1 to Mobile MSC E/// AXE10
>
> I assume the hardware module is detected as the following message appears:
> wcte12xp: VPM present and operational (Firmware version 117)
>
> Calls are initiated via a SIP Client with G729, codec available on the 
> server.
>
> On most of the calls, the quality is crystal clear - however, on some 
> specific numbers, there is a huge echo perceived on the SIP client. 
>
> This happens to some specific numbers, though 99%+ of the calls are ok 
> - all these numbers (with or without echo) are served by the same E1, 
> so nothing changes on my side. I am connected to a mobile GSM 
> operator, when I call this number from one of their cellphones, there 
> is no echo...
>
>
> Any suggestions as what to check ?
>
> Many thanks, 
>
> J.
>
>