Switching outgoing calls to backup trunk

[kugla007]

Hello,

we have two trunks set up where one is primary and the other is backup. Our provider has set up the incoming calls so that if the primary link fails, the calls are routed to the secondary trunk. Incoming calls are working fine upon primary link failure - they are routed through the secondary trunk.

The problem is with the outgoing calls. When the primary link fails it takes too long for 3CX to switch to the backup trunk for outgoing calls.

Is there a way to set up 3CX so it can detect the failure of the primary link and switch to the backup trunk faster?

Thanks in advance!

 

[IoannisM_3CX]

Hello @kugla007

In order for PBX to transfer the call through the secondary route, it has to receive response for its INVITEs from the provider. If the provider does not reply to the PBX's INVITES (because an error occurs) then the PBX will continue this process for 32 seconds in order to stop sending invites for the first route and go for the second.

If you run a capture at the time where you try to initiate outbound call, you will see multiple unanswered INVITES from the PBX to the provider.

Thank you

 

[kugla007]

Thanks!

Is there a way to decrease the length of this process?

EDIT: The status of the primary trunk still remains Registered even after 32 seconds. When we try an outgoing call the VoIP Phone timeouts first. 3CX Extension gets stuck in "Dialing". We have to manually disallow inbound and outbound calls for that trunk - then it goes to "Not registered" and only then the outbound calls go through the secondary route...

 

[IoannisM_3CX]

No, unfortunately this is not something that can be handled by from the PBX, but you can always think the solution of using a 3CX supported provider as the supported ones, are providers that we have tested for their functionality with 3CX PBX in order to eliminate such problems.

Thank you

 

[kugla007]

The status of the primary trunk still remains Registered even after 32 seconds. When we try an outgoing call the VoIP Phone timeouts first. 3CX Extension gets stuck in "Dialing". We have to manually disallow inbound and outbound calls for that trunk - then it goes to "Not registered" and only then the outbound calls go through the secondary route...

 

[YiannisH_3CX]

When the trunk is not registered the PBX will automatically try the second route. But when the provider is still registered the PBX will try the primary route first. From there we depend on the answer from the provider (or the lack of one). You will need to run a capture while the provider is down and check the communication between the provider and the PBX at that time.
There are a few parameters that matter in this scenario. Is the provider IP based or authentication based? What is the register timeout of the provider? If the provider is down and the register timeout of the provider is 600 seconds then the PBX will need 10 minutes to realise that the connection is down.