[OpenSIPS-Users] Ways of manipulating the From header of CANCEL

[Ricardo Martins]

Guys, I've been reading a lot on the list and testing on our servers 
(opensips 1.5) for some time but I still have a big issue!

1) If I use uac_replace_from on REQUEST route, the from header got 
miswritten (truncates) when using it twice. Bad for me, when intended to 
use it to provide backup routes on a call failure. But...

2) When I use uac_replace_from on BRANCH route, the replacement works 
realy fine. In order to use a backup provider, I just arm the 
branch_route and, on branch route, execute uac_replace_from with the 
proper username/domain for that specific provider. The result is ok. The 
from header is properly rewriten, many times I need at the same 
transaction. But...

3) When opensips receives a CANCEL, it do not rewrite the from header, 
prior to send it to the provider. Neither using the uac_replace_from 
function, neither using subst function (from textops). I read that 
CANCEL is locally generated, and that's why those funcions do not affect 
it. I read too that the uac_replace_from used on INVITE was expected to 
work on CANCELs automaticaly. But apears to not work when using 
uac_replace_from on BRANCH routes. And I tryied it with 
from_restore_mode parameter on 'manual' and on 'auto' mode.

4) Thats why I got a big of an issue! I MUST use the uac_replace_from on 
BRANCH routes to work with backup providers. And I MUST replace the from 
hdr of CANCEL, as my providers are rejecting CANCELs with diferent from 
headers!

Do anybody could put this kind of environment to work? Have any clue 
about it?

Regards!

Ricardo.