[reSIProcate-users] Overriding expiry times in REGISTER requests

[Max Bowsher <maxb@xxxxxxxxxxxxx>]

I was thinking of overriding the expiry time in registrations to be a 
maximum of 2 minutes, and using this to ensure that clients behind NAT 
maintain an open NAT pinhole - I was considering this to be a preferable 
solution to \r\n\r\n-style keepalives because there is implication in 
the OpenSER docs that there exist NATs which won't keep a UDP pinhole 
alive unless there is outbound traffic.

RFC3261 says that the expiry the client passes to the server is a 
suggestion only, so from a standards perspective this seems OK to me.

However, DUM doesn't seem to have any support for doing this. Hacking 
something into ServerRegistration doesn't look to be too hard, but I'm 
wondering why the support is missing - Is it simply a case of no-one 
having cause to implement it, or is it known that client support for the 
server enforcing a short registration expiry is poor?

Max.