I use asterisk 1.4 before upgrading to 188.8.131.52. Call waiting is OK, and music on hold works noraml.
when I upgraded it to 1.6.0.x, it is also no problem. but after I upgraded to 1.6.1.x or 1.6.2.x, I can’t use my phone to make call waiting to answer the 2nd call, and can’t switch 2 calls, either.
I capture the new flow, and found that when I answer the 2nd call and do switch call to one to another, asterisk could not answer the right 200 with SDP. it responses recvonly in two 200 SDP.
maybe it is because the invite Cseq, I guess. but I don’t know why the old version asterisk would be compatible, but the new version has the problem?