Disable/Remove 503 Service Unavailable Message

I was wondering if there is a way of removing the all-circuits-busy-now error or can I simply delete the files? Here is my scenario.

Two Asterisk Servers and using each as a B2B Agent to a PBX. Each Asterisk is connected to a different SIP Trunk provider. So:

SIP1 <–> Asterisk1 <–> PBX01
SIP2 <–> Asterisk2 <–> PBX01 (same as above).

My issue is with outbound calls in the event of a 503. PBX01 has both Asterisk1 and Asterisk2 in the route table and utilizes them in a round robin fashion. If SIP1 returns a 503 (Congestion) then PBX01 knows to go ahead and retry the call against Asterisk2.

This works perfect except for one item. Asterisk1 returns the all-circuits-busy-now.ulaw and starts playing it. Due to early media/such, the user hears this message while PBX01 is silently trying Asterisk2 to complete the call. PBX01 completes the call against the second Asterisk box and the call is up. The problem is, the end user may have hung up upon hearing the all circuits busy message.

If anyone knows of an easy solution that would be great.



You are using a FreePBX based distro right? Because vanilla Asterisk don’t have a predefined dialplan.

So basically you need to edit or override the Macro: [macro-outisbusy]. I’m wondering if its not better to use a SIP proxy?

Yes, it’s a FreePBX Distro we are using. We looked at the SIP Proxy option but we do have some devices that connect to the Asterisk box which is why we ended up going this route. Thanks for the suggestions on the [macro-outisbusy] item.