I have been struggling with this for a number of nights now! All internal calls (ext to ext) work fine picking up the registered STUN address (email@example.com), but as soon as a call comes in from the SIP trunk it looks for firstname.lastname@example.org:5060. The trunk has been configured to send to ext 101, but it does not pick up the correct IP for the ext. The OS is Vista Home Premium, but in theory it should work. Has anyone encountered this before?