I have just (last month) brought up * with ISDN & soft phones. I am using Workstation->SIP or iax->*->isdn4linux->hisax->EICON Diva ISDN (not Pro)->uk(bt)isdn lines I am currently trying SIP clients - the last is an evaluation of SJphone, but this problem does not seem to depend on the Workstation end Outgoing calls leave unacceptable levels of echo, noticable by the outside party, but almost none from the 'inside'. Does anyone know if echo cancelation is applied by carriers at their analog/isdn bridges? Or do we have to provide it on the back end of the isdn? I'm assuming that my echo is not a local problem, but ... anyone any ideas? Dave Kitchen - InSync Technology Ltd