[Serusers] nat_ping problems

[Jev]

Andres wrote:

>> Is there something basic I'm missing here? How have people made this 
>> configuration work? Is there anyone actual using nathelper/rtpproxy or 
>> mediaproxy in production?
>>
> We see this all the time.  The only reliable way to make this work is to 
> turn on the keep-alive on the UA so that it sends packets from the 
> "inside" out to SER.

But what about phones that don't support UA keep-alives? Do you suggest 
that I put my re register period way down?

I wonder is it possible for ser to query the UA on an existing udp 
session, something like an options query, that will illicit a response 
from the UA. It may generate as much traffic as a register, but it would 
probably be less load on the server, so perhaps the lesser of two evils?

I would like to try and identify a solution based in ser, so I don't 
have to rely on every phone supporting keep alives or the nth feature.

-Jev