[asterisk-ss7] echo on a SS7/E1

[Jean Cérien]

Hello

Quick update... I think my problem is fixed. As Jorge was suggesting, the
echo canceller needs to be activated through the echocan command. I was
under the wrong impression that the HW EC was starting automatically, and
did not need any activation command.

Sound quality is may be not as good as without, somehow a bit mettallic, but
I am not sure if it is just an impression or what !

Thanks for your help

Regards,

J.


On Thu, Apr 15, 2010 at 8:24 PM, Jean Cérien <cerien.jean at gmail.com> wrote:

>
> All : many thanks for your replies - I havent replied before as I was
> trying to get an environment where I can reproduce this echo. Only some
> progress so far.
>
>
> A few questions re your comments:
>
> - is there a way to disable via software the VPM module ? I take the
> suggestion of removing physically the board as interesting, unfortunately,
> the server is in a remote location with strict access conditions... if it
> could be done by software, that would be great
>
> - I've upgraded to the latest dahdi (2.3.0) tonight, I will see if there
> are any improvements
>
> - regarding echowhenbridge, echocancel, etc... do these parameters apply to
> hardware echo canceller as well ? my understanding was this applied only to
> software EC
>
> - does anyone has a proper doc for this module ?
>
>
> Many thanks for your precious help,
>
> J.
>
>
>
> On Thu, Apr 1, 2010 at 7:07 PM, John Bigelow <jbigelow at digium.com> wrote:
>
>> 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.
>> >
>> >
>>
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