Possible trunk failover problem

I have just setup a SIP trunk to another office, where a small IP PABX is setup with a single FXO port so we can dial local calls from our main office to that location. The trunk works fine, although in my outbound route I have selected to use our local misdn trunk if that line is engaged. I get the following when I am already on one call and try to make another up the same trunk, hoping it will failover.

Executing [[email protected]:23] Dial(“SIP/3099-08879448”, “SIP/bomsiptrunk/64583170|300|TW”) in new stack
– Called bomsiptrunk/64583170
– Got SIP response 486 “Busy Here” back from
– SIP/bomsiptrunk-0885c5f0 is busy
== Everyone is busy/congested at this time (1:1/0/0)
– Executing [[email protected]:24] Goto(“SIP/3099-08879448”, “s-BUSY|1”) in new stack
– Goto (macro-dialout-trunk,s-BUSY,1)
– Executing [[email protected]:1] NoOp(“SIP/3099-08879448”, “Dial failed due to trunk reporting BUSY - giving up”) in new stack

After this my line hangs up and doesn’t try to dial my second preferred trunk.

Anybody have any ideas that I can try or look at to test further.


Further to my last … it makes no difference if i select max channels or not in the Trunk config. I had it set to 1 originally as there is only one line available, but I changed it to nothing and the result is the same.

you trunk is reporting busy, the behavior is correct. Your trunk needs to report congestion of some sort in order to fail over. It’s equivalent to dialing a phone number and that number is busy, you don’t keep trying to dial that same phone number over and over out multiple trunks.