[SR-Users] NatHelper's Keep-alive timeout behind proxy

[Asgaroth]

Hi All,

We are looking to enable nathelpers keepalive timeout parameter where it 
will remove an aor's contact if it doesn't receive a reply from the ua.

The problem we have is that our registrar's are seperated from our 
proxies, so this means nathelper is sending options messages via the 
proxy to the ua. In this case, if the us has lost connectivity, the 
kamailio proxy sends a 408 Request Timeout back to the registrar and the 
nathelper module sees that as a response to the initial options message 
it sends, so it never actually removes the contact from the location table.

Is there a way I can stop the proxy from sending any responses for these 
specific nat ping/options messages, or, is there a way I can tell the 
nathelper modules that a 408 response should be treated as the ua being 
down and then after the timeout interval remove the contact from the 
location table?

I've had a read of the nathelper, tm and sl modules but I didnt see 
anything that jumps out at me that I could achieve one or the other 
possible solutions I mentioned above.

Does anyone have any suggestions or pointers on how we can achieve this 
with the registrars being seperate from the edge proxies.

Any pointrs/tips etc would be greatly appreciated.

Thanks