Hi, I tried to use the SER SIP server together with a number of different UAs. I successfully used a Pingtel phone, pingtel softphone, the Ubiquity UA, and kphone on linux. However, when I tried to use SIPC from Columbia Uni I keep getting eror messages 400: Bad Request. As all the other UAs are working fine I assume this may be a problem with sipc. Have you any experiences with using sipc and ser? I attach an error log between the Pingtel phone (139.153.254.222) is trying to send an INVITE to sipc (139.153.254.34). SER (and ngrep) are running on 139.153.254.50. (registrations are going through fine and also invites the other way (from sipc to pingtel) go through ok). Thanks very much for your help! Regards, Mario -- Mario Kolberg phone: +44 (0)1786 46 7440 Lecturer in Computing Science fax : +44 (0)1786 46 4551 email: mko(a)cs.stir.ac.uk Department of Computing Science and Mathematics University of Stirling Stirling FK9 4LA Scotland, UK -- The University of Stirling is a university established in Scotland by charter at Stirling, FK9 4LA. Privileged/Confidential Information may be contained in this message. If you are not the addressee indicated in this message (or responsible for delivery of the message to such person), you may not disclose, copy or deliver this message to anyone and any action taken or omitted to be taken in reliance on it, is prohibited and may be unlawful. In such case, you should destroy this message and kindly notify the sender by reply email. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of the University of Stirling shall be understood as neither given nor endorsed by it.