I set up asterisk, with 2 sip providers.
With the first provider everything runs just fine, but with the second one, some of the incoming calls don’t reach my asterisk. (except that it runs fine too)
I first tought it was a problem with that provider but when I set it up with a softphone (x-lite) directly, it works fine.
turn on sip debug for the peer and see what you get in the way of sip packets. if nothing, i would suspect your port forwarding rules either aren’t in place, or your NAT is not keeping a hole open (are you using a qualify statement ?) or there is something else blocking the traffic.
I investigated and asterisk lacks of a really important feature, a way to define the registration expiration for EACH sip provider.
if you set defaultexpiry to please one of the sip provider for example (every 30 mins) the other who expect it every 5 mins will assume you’re not connected anymore.
too bad that defaultexpiry only works in general context.