What is needed for a second sip trunk on MBG to a different carrier

[lchung@candw.ky]

Hi Guys,

I would like to add a second SIP trunk to my Mitel MBG.
What license info if needed and what configuration is needed.
I have tried to add the port configuration and sip configuration on the MBG but the system seem to try to establish a connection using the first carrier MBG ip.

Any help would be useful.
Thanks

[acejavelin]

Did you build the network element in the 3300 and all the related SIP stuff? The MBG is the session border controller and an interface between "public and private" basically... The real configuration all happens in the MiVoice Business.

[lchung@candw.ky]

Yes the network element is build and also all the SIP trunk stuff.
When I do a maintenance packet trace on the MBG, the trace is showing a setup from the first carrier mbg terminating ip going to the registrar of the second carrier, which will fail.
Is there a setting in the PBX that will tell the SIP trunk to use a specific ip address on call setup? 

[acejavelin]

I guess I am confused... if you have a separate network element, communicating with a different external FQDN/IP then how is the invite being sent to the wrong carrier/IP? You essentially treat each SIP element as a separate trunk group, then access it via ARS and try a call, the invite should go to the MBG which then adjusts the IP's for the network translation (but shouldn't change it's destination) and forwards it off on the public interface to the destination carrier...