Gaëtan, The echo arise at 4w/2w conversion point, normally at the far end. Try to call another phone number assigned to your BRI, i.e. call back to your Asterisk server. If you use a Polycom phone to initiate the call and another to receive the call, you have the perfect link: 4 wires with not 4w/2w conversion. Under this test, theoretically you must not have echo. If so, it is necessary to look elsewhere, at your Asterisk box maybe. Modifying the rx/tx gain is a good practice too.
Best Regards Jorge Mendoza Gaëtan Minet wrote: > Thanks ! > > We installed it in the interim and have a lot of calls with far-end > echo :(. > But it seems the solution could be to reduce the TX gain on our side > (these are using polycom phones, and indeed I can see a big > amplitude imbalance between tx/rx on a recording). It's under test, I > hope it'll solve it. > > Kind regards, > > Gaetan > > > On 09/09/2009, at 16:22, Jorge Mendoza wrote: > > >> Gaëtan, >> >> They are using as gateway to the pstn. In fact, they are remote >> gateways >> for a centralized callcenter: >> >> [pstn] «--» [BRI] «--» [internet] «--» [callcenter] >> >> Regards >> >> Jorge Mendoza >> >> Gaëtan Minet wrote: >> >>> Thanks >>> >>> Are you using these to connect isdn phones to the voip or to as a >>> gateway to the pstn for a voip system ? >>> >>> Kind regards >>> >>> Gaetan >>> >>> >>> On 08/09/2009, at 19:40, Jorge Mendoza wrote: >>> >>> >>> >>>> We have some installations with smartnode 4554, (same tail echo >>>> cancellation) without problems so far. >>>> >>>> Jorge Mendoza >>>> >>>> Gaëtan Minet wrote: >>>> >>>> >>>>> Hi >>>>> >>>>> Is anybody using these ? >>>>> >>>>> Gaetan >>>>> >>>>> >>>>> Begin forwarded message: >>>>> >>>>> >>>>> >>>>>> *From: *Gaëtan Minet <[email protected] <mailto:gminet- >>>>>> [email protected]>> >>>>>> *Date: *Sat 22 Aug 2009 16:29:42 GMT+02:00 >>>>>> *To: *Asterisk Users Mailing List - Non-Commercial Discussion >>>>>> <[email protected] >>>>>> <mailto:[email protected]>> >>>>>> *Subject: **[asterisk-users] Patton smartnode 463x (BRI) 25ms tail >>>>>> echo cancellation* >>>>>> *Reply-To: *Asterisk Users Mailing List - Non-Commercial >>>>>> Discussion >>>>>> <[email protected] >>>>>> <mailto:[email protected]>> >>>>>> >>>>>> Hi all >>>>>> >>>>>> We use pci/pci-e BRI cards in our installations. Due to echo >>>>>> problems >>>>>> (that was before Oslec and others), we quickly switched to cards >>>>>> with >>>>>> hardware-based EC. >>>>>> So we use exclusively Digium B410p cards that provide 64ms tail >>>>>> EC. >>>>>> >>>>>> For several reasons we'd like to switch to external BRI gateways >>>>>> like >>>>>> the Patton smartnodes (the price is getting really close to a >>>>>> B410p). >>>>>> >>>>>> I'm however curious about their HW EC. I see in the datasheets >>>>>> that it >>>>>> only has 25ms tail per channel (pri are 128ms, but not BRI). >>>>>> Are some of you using these gateway and do your experience (many) >>>>>> echo problems on calls ? >>>>>> >>>>>> Our other alternative is to use sangoma cards that have 128ms HW >>>>>> EC >>>>>> and seem more stable overall, but it is yet a bit more expensive. >>>>>> >>>>>> Thanks for your feedback. >>>>>> >>>>>> Regards, >>>>>> Gaetan >>>>>> >>>>>> >>>>>> >>>>>> _______________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- AstriCon 2009 - October 13 - 15 Phoenix, Arizona Register Now: http://www.astricon.net asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
