On Wed, 28 Feb 2007, Dave Sherman wrote: > The T1 cards with hardware echo cancellation were a lifesaver for us, > not sure if any other manufacturers are producing a card with that > feature. I know Sangoma also makes one. They also do a lot more in hardware (ie - the price tag skyrockets). > Can't say much about the FXO/FXS cards from Digium, besides the fact > that they work as expected. We have used them for testing, but do not > have any in a production server. Avoid the FXO/FXS cards whenever possible. :) My advice would be to get digital trunks (BRI's or PRI's), and if you need FXS ports (for fax machines, door phones, etc), get a channel bank to split a T1 into multiple analog lines. If you can't get digital lines, you can get channel banks that will let you configure (for example) 16 ports as FXO and 8 ports as FXS - so you could plug 16 analog phone lines into it, and 8 analog extensions. > The biggest challenge we've had is with faxing. We ended up bringing in > dedicated analog lines from Qwest for our faxes at one installation, but > faxes at the other installation are running off Sipura (now Linksys) > SIP-to-analog converter boxes, and they seem to work fine -- but they > also use the faxes less than the folks who got analog lines. Have you tried the fax support for Asterisk (or OpenPBX)? I've heard good things about it; haven't ever tried it, though. > I do seem to recall reading that having more than one card in a single > server can lead to performance issues, because the telephony interface > cards tend to generate so many interrupts on the system bus, and they > need to run in real time -- if you have too many cards, it will start to > show in performance rather quickly. The Sangoma cards solve this - the cards don't generate a pile of interrupts. ------------------------------------------------------------------------ | nate carlson | natecars at natecarlson.com | http://www.natecarlson.com | | depriving some poor village of its idiot since 1981 | ------------------------------------------------------------------------