Is it ok to post attachments to this list? If not I will post the SIP trace in the email body.

both are fine -- there is a limit of 40k for the messages posted to the mailing list, no matter there are attachments or inline content.

Hi

Here is the SIP trace. The IP's are as follows

PSTN Gateway 10.0.0.1
Asterisk 10.0.1.1:5061
Openser 10.0.1.1:5060
SBC 11.0.0.1

In this trace I am substituing the SBC with X-Lite as I dont have access to the SBC at the moment. But is should illustrate what is going on hopefully.

Thanks for any help that can be given.

Regards

Jon