atcomsystems.ca/forum Forums TDM Business Telephone Systems Samsung Telephones & Systems OS7100 E164 format outbound cli issues

Hi All,
Out of the blue, we have a OS7200s with Gamma SIP trunks where the callers CLI is not registering on recipient's mobile .(withheld or private number).
I have been informed that Gamma have a new SBC and that E164 call format is now required for the correct CLI to be forwarded to recipient and that a "p-asserted ID Use" header must be included in the initial INVITE.
The only place I can see to alter any parameters is in menu 5.2.13 where there are options for:
P-asserted ID Use - options are Primary, Alternate or None.- I've used Primary
E164 Support - options are Enable or Disable - I've set this to Enable.
Privacy Header Value - any value allowed, default is "none" or "id,critical". I've set this to None.
In menu 2.4.3 (send cli number), I've add 44 in front of the number and deleted the leading zero.
Seems to work to EE or O2 numbers but not to 3-Mobile or SKY mobile.

Gamma say the P-asserted ID is not being sent with the initial invite.

Does anyone know what parameters need to be set to enable E164 to work correctly.
Thanks,
Smudger008.

I have similar problems with SIP from TELEAG, the E164 formats don't arrive cleanly there either. Maybe someone has information about what the best practice for setting it up looked like. I couldn't find anything useful in my documents; my SIP cookbooks are always provider-specific, usually without E164