So then the system I'm building (P4 2.66GHz) should do fine in the encoding/decoding (which I assume accounts for most of the echos, and poor quality).
-Dave -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Andrew Kohlsmith Sent: Wednesday, November 03, 2004 10:33 AM To: [EMAIL PROTECTED] Subject: Re: [Asterisk-Users] An anniversary and a lament for FXOs On November 3, 2004 10:13 am, [EMAIL PROTECTED] wrote: > use Sipura SPA-3000s but they're only marginally better. How is it that > my Panasonic 4 line SOHO phone system (KX-TG4000B) can have four > stable, reliable FXOs with no echo at all in a device with a total cost > of <$500? It seems to me that there ought to be hardware available that > behaves just as well, but bridges the PSTN to the SIP/IAX domain? VOIP introduces latencies that Just Do Not Exist in non-VOIP scenarios. I would have thought that after a year with Asterisk you would have come to that conclusion. > I've read a lot on the list about how difficult designing FXOs can be, > but that flies in the face of the fact that every small multi-line > phone system has them...and without expection those behave better than > the devices I've been able to try with Asterisk. The Sipura SPA-3000 > has several settings to adjust for line impedance and > inductive/capacitive line loading....lots of settings, but it provides > nowhere near the basic performance of one of the lines on the Panasonic > KSU. It's simply mind boggling. You're tuning the hybrid; the problem lies in the additional latency incurred with VOIP -- If you took the Panasonic system hardware and VOIP'd it you would likely see similar issues that you see with the X100P, TDM400P and even channel banks. You need a good stable and performance system to get good VOIP quality. There is no substitute. Case in point: I was running an X100P and a TDM410P in a P90MMX -- VOIP calls were pretty good but anything over the POTS was kind of shitty... put the exact same hardware into a P3-700 and the POTS problems went away for the most part. > So, while I've posted with respect to FXOs previously, I must ask > again....what FXO interface device can anyone recommend from real > experience? Personal preference: T100P and a channel bank. Excellent-quality hybrids and a good, solid computer interface. It's about double the cost of your Panasonic system, though, but can handle 24 lines instead of 4. -A. _______________________________________________ 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 _______________________________________________ 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