[asterisk-ss7] echo on a SS7/E1

[Jean Cérien]

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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