SOLVED Action Based on Bridge Return Value - Possible?

[JamesBorne]

My upstream sends a "Account in Use 156" when the sessions are maxed out.

I would simply like to inform the user instead of the rewrite to NORMAL_CLEARING (480) which causes the user to false panic.
I have modified an existing outbound route with an extra group to handle the action as follows:


At log point 1, the Freeswitch log successfully writes "Hello .... Account in Use 156"
But on the condition point 2, there is no value attached to the variable resulting in a FAIL on match:


I have tried setting the second condition to have an Inline of True, and I have tried exporting a new variable in group 1 and checking that. The exported variable also has no value on condition check.

Could someone suggest how I could use these variables in post-call check to see if the call failed due to max sessions?

Thanks all!

 

[Adrian Fretwell]

Hi James,
I replicated what you are trying to do and get the same result. I think the reason is that all the conditions in a dial plan statement get evaluated before any actions are processed. So when ${sip_invite_failure_phrase} is evaluated, it has not yet been set by the result of the bridge process. So it never matches so you always see the anti-action. That's my understanding, I probably have not explained it very well.

I think you can do what you want using LUA, I modified an example shown here:
https://freeswitch.org/confluence/display/FREESWITCH/Cause+Code+Substitution+Example

I modified my channel allowance on the SIP trunk to zero, so if I try to make a call the SIP proxy responds to me with "Request Terminated: Channel limit exceeded".

So the relevant bit of my my outbound route looks like this:


And this is the lua code:

-- channel_limit.lua
-- check for response text and apply hangup cause
--
uuid = argv[1];
api = freeswitch.API();
sip_invite_failure_phrase = api:executeString("uuid_getvar "..uuid.." sip_invite_failure_phrase");
if sip_invite_failure_phrase == "Request Terminated: Channel limit exceeded" then
    if ( session:ready() ) then
    session:execute("playback", "/usr/share/freeswitch/sounds/en/gb/rachael/ivr/8000/ivr-no_route_destination.wav")
    session:hangup("NORMAL_CIRCUIT_CONGESTION");
    end
end

Maybe this is a step in the right direction for you. Happy New Year!

 

[JamesBorne]

Hey Adrian,

Mate you were spot on. Thank you so much for sourcing a solution and testing it for applicability!
Your explanation on condition variable parsing made a lot of sense. I also think you're right based on past experience.

If anyone else tests this, just be sure to change the hardcoded path to the sound file to a valid path, and to check variables with:

local log = require "resources.functions.log".call_flow_monitor
log.notice("channel_limit: " ..  sip_invite_failure_phrase )

Happy new year to you too!