Hi,

I'm trying to configure a SIP connection to a 3rd party B2B SIP device, then B2B will relay to a Huawei (SIP) device on the other end.

topology:
IP Phones(SSCP) ------CCM7 -------(provider)--B2B---------Huawei---pstn

configuration:
CCM is configured with SIP trunk with ip address of the B2B and route pattern uses the SIP trunk configured.  MTP required uncheck as of the moment.  codec G711uLaw and No authentication required.

Problem:
Outgoing call from IP Phone to PSTN gets fast busy signal.  When placed a sniffer in between CCM7 and B2B gateway, i didnt see any sip invite initiated by the CCM7. CCM7 and ip phones only have traffic reachability to B2B but not Huawei.
The provider (B2B to pstn) was tested using altitude(as claimed by the customer) and works fine but we are testing using CCM7.

Question:
1> Am i right to use CCM trunk to connect to the B2B sip
2> Any additional configs i need to configure? Misconfiguration?
3>Should i expect SIP invite to be sent by CCM when call is triggered by ip phones?

Thanks,
Jeff