What type of card for PRI

Hello. I need to connect my server to ISDN PSTN network. I’m looking for a card for that - I prefere a Digium. But I don’t know which one is better. One type of cards have hardware echo cancelattion and one type no. And I need to know can I use on typical card without hardware echo cancelation a software echo cancelation and how is working. And the last question - where is ECHO on ISDN - is digital line and a voice is also digital ?. Please help me. Thank’s. Bye

hi. your two main manufacturers are digium and sangoma, digium.com and sangoma.com. both have full product lines ranging from 1 port to 8, available with and without hardware echo canceler.

I know there is a Digium and Sangoma cards from 1-8 ports but i need to know where is a diffrent between hardware echo cancelation and card without hardware echo cancelation. Can I use a software echo cancelation with card without hardware echo cancelation. And please write me - how can be ECHO on ISDN digital line. Voice is digital not analog so where is echo. Thank’s for all. Bye

The echo can appear when you have IP based handsets.

You can do software based echo cancellation but will use CPU time. I use a Sonoma A102 card utilizing a single PRI in two systems running AMD Athlon 64 3GHz processors and echo is seldom a problem.