With hw echo cancellation you are pretty much guaranteed to not have any problems. At least with Sangoma cards. I cannot speak for the other manufacturers. I believe most of not all HWEC also does other things to help clean up the sound and maybe even add background noise etc. so the over all sound quality is improved as well.
Some installations will work fine just with the included SWEC, some will not. Some will sort of kind of sometimes work ok maybe. No scientific way to determine if you will need it or not. I believe the farther away you are from the phone companies exchange the more likely you will need it. With Sangoma cards, I believe you have the option of ordering without HWEC from your supplier and if you find you need it, you can send the card to Sangoma and they will upgrade it for you or send you a HWEC version and charge you the difference. If you phone Sangoma they will be able to answer that more difinitively. -----Original Message----- From: Zeeshan Zakaria [mailto:[EMAIL PROTECTED] Sent: Thursday, March 08, 2007 11:30 PM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: [asterisk-users] When to use Echo Cancellation cards? In what scenarios non-Echo Cancellation cards (T1/E1/FXO) should be used ? Don't all good and professional installations need echo cancellation cards? Are there people out there with non-Echo Cancellation cards for T1 or 8 FXO ports and who really don't have any echo issues and they are running serious businesses? -- Zeeshan A Zakaria _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users