[OpenSIPS-Users] No to tag in CANCEL response - Via removed

[Chris Maciejewski]

Hi,

I have a strange problem with OpenSIPS 1.11.1 removing Via header and
routing 487 response with no Via header (which is than dropped by UA1
as invalid SIP packet - missing Via).

You can see the call flow below:

https://dl.dropboxusercontent.com/u/3182365/call-cancel/call2_index.html

I think the problem is related to the fact UA2 is incorrectly not
adding To tag to F10 and F11. Since OK 200 in F10 is final response,
To tag should be present?

Any suggestions how to fix this issue and make Proxy not remove Via
header very much appreciated.

Best regards,
Chris