[OpenSIPS-Users] help on failover routing

[Liviu Chircu]

On 20.03.2020 12:37, johan wrote:
>
> Hence,
>
> - when the softphone is registered, a call comes on that DID in udp 
> (we do lookup_location) and we send it to the user in tls (this works)
>
> - when the softphone is off for a long time, there is no record in 
> location so then I route the call via the provider to his real mobile 
> number (this works also)
>
> - the problem is when the mobile looses his dataconnection, then I do 
> have a record in location, I try to send the call, which will fail.   
> Upon failure, I drop the record in subscriber. And here the problem 
> begins.
>
> The invite is adapted at this point already for tls => provider 
> doesn't want it as he is udp.
>
>
> So how can I have the original request back for routing to the real 
> mobile number ? Or how can I check if the user is still connected (aka 
> how can I send options to see if he's alive) before calling t_relay. 

Hi, Johan!

1.  this solution of calling remove() after a routing failure is nice.  
Alexey Vasilyev put together a feature request [1] related to this 
problem, where he asks for an automated mechanism of deleting a contact 
whenever its TLS connection is found to be dead.

2.  Did you try to force the sending socket of the INVITE ($fs variable) 
to your "udp:1.2.3.4:5060" listener?  I think this should work inside a 
failure_route and should properly route to your provider via UDP.  Also, 
I believe Bogdan fixed this recently [2] (but master branch only?!), 
such that "$fs" is not set to the TLS listener inside failure_route - 
might wanna check.

3.  As a long-term solution to this problem, we are working on adding 
RFC 8599 Push Notification support via SIP in OpenSIPS 3.1.  The spec is 
still rather new, but I'm curious if your app's SIP stack supports it 
:)  Basically, this will allow you to wake up the phone so it 
re-registers whenever you need to deliver an INVITE to it, in a 
standards-approved way.

Best regards,

[1]: https://github.com/OpenSIPS/opensips/issues/1769

[2]: https://github.com/OpenSIPS/opensips/commit/f73abff9

[3]: https://tools.ietf.org/html/rfc8599

-- 
Liviu Chircu
www.twitter.com/liviuchircu | www.opensips-solutions.com

OpenSIPS Summit, Amsterdam, May 2020
   www.opensips.org/events