[Serusers] ReTransmission of CANCELs on 0.9.7

[rupert.organ at bt.com]

Hi All,

Has anyone come up against an issue on 0.9.6 / 0.9.7 whereby a SIP App
Server, delivers a CANCEL to the SER.
The SER proxies the CANCELs to all the forked endpoints.
At the same time it sends "200 Cancelling" back to the SIP App
server...(this suppresses CANCEL retransmission from the SIP App
server).
If one of the CANCELs from the SER to the SIP UA gets lost....the phone
keeps ringing.
There is no CANCEL retransmission on the SER !!!
There is CANCEL retransmission on the SIP App, but when it sends SER
replies "no pending branches"

Ideally want the SER do CANCEL retransmissions. I understand the timers
were rewritten in 0.10.x but this is not hardened version like
0.9.6....any suggestions?

Thanks in advance

Rupert