Hello Support,
We are facing a scenario in Telcobridges Version: 3.3.13.151. When making an outgoing call, we observed two situations:
When we receive a 200 OK SDP with ISUP ANM, audio is established.
However, when we receive a 200 OK SDP with CON, audio is not established.
Is there any adjustment that can be made in the SBC?
ISUP is not supported on SBC, so you must be talking about TMG units?
ISUP CON should be supported normally.
Please open a case here: https://telcobridges.odoo.com/
We will need a TBreport and the signaling traces.
Hello, thank you for your reply.
The NAP scenario is SIP-I.
In any case, I have triggered the link below.
Thank you.
The problem is probably not on the ProSBC side.
I have seen this issue before, especially with some older PSTN switches that may require specific adjustments.
In many cases, this happens in scenarios involving an automated answer service or IVR, where a 200 OK is sent immediately. During ISUP interworking, that can result in a CON being generated instead of an ANM.
One possible workaround, if you are on the receiving side, is to force a 180 Ringing and/or 183 Session Progress with early media before the final answer. In that case, the previous signaling can generate an ACM, and the final answer is more likely to result in ANM instead of CON.
That said, I would need a few more details to better understand your specific scenario.
If you are based in Brazil, I may also be able to help you directly, as we provide operational support for telecom companies and carriers in Brazil.