Hi

We're using OSBC 1.1.6-6 to protect our asterisk server from an ITSP. OSBC is configured for B2BUpperReg Mode.

Asterisk is able to register to the ITSP just fine, with OSBC relaying the SIP REGISTER messages between the asterisk and the ITSP.

Outgoing calls work just fine too.

Incoming calls from the ITSP however are failing. OSBC receives the SIP INVITE message from the ITSP on its backdoor interface, but instead of sending it on to asterisk, it sends it on to its own main interface.

In the below traces:

• a.b.188.3 is the ITSP
• x.y.81.84 is the ITSP facing interface of OSBC (= backdoor interface)
• x.y.83.100 is the asterisk facing interface of OSBC (= main interface)
• x.y.83.84 is the IP address of asterisk

This is a trace on the ITSP facing interface of OSBC:

0.000000 a.b.188.3 -> x.y.81.84 SIP/SDP Request: INVITE sip:x-reg-id-sip%3Axxxxxxxxx%40x.y.83.84@x.y.81.84:5062, with session description
0.004576 x.y.81.84 -> a.b.188.3 SIP Status: 100 Trying

And these are the SIP INVITES that OSBC forwards to its own main interface on its own loopback interface.

0.000000 x.y.81.84 -> x.y.83.100 SIP/SDP Request: INVITE sip:x-reg-id-sip%3Axxxxxxxxx%40x.y.83.84@x.y.83.100:5060, with session description
0.483772 x.y.81.84 -> x.y.83.100 SIP/SDP Request: INVITE sip:x-reg-id-sip%3Axxxxxxxxx%40x.y.83.84@x.y.83.100:5060, with session description
1.483902 x.y.81.84 -> x.y.83.100 SIP/SDP Request: INVITE sip:x-reg-id-sip%3Axxxxxxxxx%40x.y.83.84@x.y.83.100:5060, with session description
3.484280 x.y.81.84 -> x.y.83.100 SIP/SDP Request: INVITE sip:x-reg-id-sip%3Axxxxxxxxx%40x.y.83.84@x.y.83.100:5060, with session description

I'm attaching my OpenSBC.ini.

Many thanks in advance for any pointers you could give us.

Season's greetings

James