What SIP Hold mechanisms does SD support?
We are running ACME Net-Net 4500 Firmware SCX6.2.0 MR-12 Patch 4 (Build 1194) SBCs. We are testing with a 3rd party SIP system that includes a soft-phone. The SD sits in-between the soft-phone and the back-end 3rd party system.
When calls are placed on from the soft-phone, the SD drops the call after 30 seconds. In other scenarios, the SD drops the call only after being put on hold for a 2nd time. We have not yet managed to enaable logging on the SD to see if the guard timers are dropping the calls.
I have looked at the mechaninsm that it uses to place calls on hold. It does it by setting c=0.0.0.0 in the re-INVITE.