Thanks Jeff,

I haven't tried to actually run Asterisk on the N900. Seems like a cool thing to do though (I use a SheevaPlug for Asterisk 1.6).

The links you have provided seems to be related to the register phase, which actually works for me. My problem is that the N900 doesn't return an OK with session description like is should after the RINGING. Instead it returns the 500 "Internal Server Error". I am thinking this has to do with some bug in the Sofia-SIP stack. However, if somebody else has successfully connected to Asterisk I guess the problem lies elsewhere.

Anyhow, thanks a lot for trying to help out!

// Jonas