Configuration of trunk failover

Hi all!
I looked around but I didn’t understood well if is possible to do…

My setup is this

freepbx ->sip trunk->cisco router1->ISDN PRI->carrier’s router 1

I would like to obtain this situation

freepbx-> sip trunk1->cisco router1->ISDN PRI->carrier’s router 1
->sip trunk2->cisco router2->ISDN PRI->carrier’s router 2

Our carrier send inbound calls onlu on the first router but in case of connectivity problem on public lines, automatically route all traffica on the second router.and automaticcally return on the first router when the public line goes up

I would like to obtain the same from my side, so in case I can’t call using the first sip trunk, automatically fallback on the second trunk and return on the first when the problem is solved.

Is possible to do this?

No need to mention cisco router and further.
Just configure multiple trunks and use them in Outbound route.

Andrew,
thanks for your quick reply;
so this is working even if the primary sip trunk will not goes down?

I would say if the 1st trunk in the list will not be able to establish a call (i.e. receive 200-INVITE from upstream) the next trunk in the list will be tried.
There is also a setting in the trunk config to keep in mind - “Continue if Busy”.

Thanks a lot for clarifyng.
Will test!!!