On Mon, 30 Aug 2004 10:28:59 -0400, Michael Graves wrote: >On Mon, 30 Aug 2004 16:21:04 +0100, Kevin Walsh wrote: > >>Rich Adamson [EMAIL PROTECTED] wrote: >>> > 3. If impendance mismatch is the (or a major contributing) factor, can >>> > we not devise some interface circuit which will allow a variable rate >>> > on the impedance so we can "dial out" the echo based on individual line >>> > conditions? >>> > >>> That would be called the TDM card. It has a chipset that was designed >>> to match telco standards in many (if not all) countries. In Canada, >>> if you have x100p echo problems, you'll have them with the tdm card >>> as well. >>> >>> You'll find plenty of discussion in the archives relative to x100p/tdm >>> echo problems unrelated to impedence mismatches. Seems there is an issue >>> with interrupt latency, pci controller, or something like that associated >>> with some motherboards that "is" impacting echo (as well as other things). >>> >>> Multiple individuals have found that replacing their motherboards fixed >>> the echo problem with these cards, but no one (as yet) as put their >>> finger on why with any degree of accuracy. Lots of opinions, but no >>> real facts to date. >>> >>> [snip] >>> >>> There is a high probability (but this is a wild guess) the echo issue >>> has something to do with the specific chipset used by the motherboard >>> manufacturer, and if that guess is correct, probably something to do >>> with how interrupts are handled or pci controller issues, etc. >>> Something on certain motherboards seem to be delaying the transfer of >>> data to/from x100p/tdm cards, and that delay is sufficient enough to >>> fall outside the limits of the echo cancellation software within *. >>> >>You could go to a lot of time, effort and expense buying a TDM card, >>fitting a new motherboard (PCI 2.2), fiddling with gains and trying >>all of the other suggestions that have been posted, or you could just >>buy an external FXO device, such as a Sipura SPA-3000, and expect it >>to just work. >> >>External devices are not sensitive to PCI latency and are not >>concerned with the brand of motherboard you use. All facilities, >>such as echo cancellation, are provided onboard rather than via a >>software driver. >> >>I don't have echo problems on my X100P (at home) but that won't stop >>me from dumping it in favour of a Sipura SPA-3000 next month, once it >>gets full UK support in firmware (caller ID etc.). >> > >Bear in mind that many of us who have been using the SPA-3000 in the US >have also been experiencing echo related problems. I'm trying the >latest firmware which is only a few days old, but I'm pretty close to >chucking it in favor of something else. >
After a day and a half of using the SPA-3000 with v2.1.0 firmware I can say that they echo problem is much better. Not wholly resolved, but better. I still have to jack up the PSTN>VOIP gain setting a lot in order to hear the incomming caller. Michael -- Michael Graves [EMAIL PROTECTED] Sr. Product Specialist www.pixelpower.com Pixel Power Inc. [EMAIL PROTECTED] o713-861-4005 o800-905-6412 c713-201-1262 "The greatest dangers to liberty lurk in insidious encroachments by men of zeal, well-meaning but without understanding." - U.S. Supreme Court Justice Louis Brandeis, 1928 ** Tag(s) inserted by Bandit Tagger98 - http://www.gbar.dtu.dk/~c918704 _______________________________________________ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
