[W52P] SIP CANCEL with "Call completed elsewhere" shows missed call

[x0r]

(02-19-2016 05:41 PM)Yealink_Karl Wrote:  Please help us to get the pcap and syslog and config.bin files, we can check something from them.
You can get more info from the link: http://support.yealink.com/faq/faqInfo?id=311

Thanks! I have sent you these files by e-mail.

In the meantime I investigated this issue further. I noticed Asterisk sent two Reason headers:

(02-05-2016 01:41 AM)x0r Wrote:  Reason: Q.850;cause=26
Reason: SIP;cause=200;text="Call completed elsewhere"

However, if I set up a SIP proxy which removes the "Reason: Q.850;cause=26" header, the call does no longer show up as a missed call, as intended.

So it seems that when there are multiple Reason headers in the same CANCEL message, the phone gets confused and this bug gets triggered.