provided by Star2Billing S.L.

Intermittent Billing Issue

All:

I have recently discovered an issue where some calls are not being updated correctly. The customer's balance is not being updated since
the call is not marked ANSWER even though it completed. The issue is intermittent.

Symptoms:

- In A2B, go to the CDR's and click on "All Calls". If you see that the TC does not contain a value, then this might indicate that
you potentially have the same issue.


Asterisk 1.4.17

a2billing.php
$agi_version = "Asterisk2Billing - Version 1.3.3 (Doudou08)";

Mysql 5.0.45

Issue:

- Calls that appear as ANSWER in the * CDRs are not marked ANSWER in A2B.

- This happens using IAX || SIP

- The issue has taken place when the caller hangs up and also when the called party hangs up as well.

- It's intermittent which makes it very very hard to troubleshoot/debug.

- There are no errors (MYSQL or a2billing.php)

- The DB is updated, the TC is not populated though and the balance is not adjusted accordingly.

- I've looked at the a2billing.php source code and traced down all the calls and I think the issue is coming from * itself, more specifically
how the DIALSTATUS variable is being populated by *. My impression is that * is at times for some reason not populating this variable causing the
issue and all the symptoms described above.

I've searched the forum to see if this has been solved and have not been able to find a solution.

Any help with this will be greatly appreciated. I understand that downgrading * would be a possible solution, one that I would like to avoid though.

Thanks in advance for any help/suggestions.

Alfredo

I'm not aware of any problem in that version of Asterisk that might cause the symptoms you're describing, although there are quite a few scary security problems with that release so you should definately upgrade to v1.4.21.
Do you have PHP's pcntl module installed?

- It shows up on my list of installed modules.

php -m

[PHP Modules]
pcntl

Are you using AGI(...) or DeadAGI(...) in your extensions?

extensions.conf

exten => 00,1,Answer()
exten => 00,2,Wait,1
exten => 00,3,AGI,(a2billing.php|1|)
exten => 00,4,Wait,2
exten => 00,5,Hangup()

a2billing.conf

dialcommand_param = "|60|HRgrL(%timeout%:61000:30000)"

Then that's your problem. Use DeadAGI() as the documentation describes.

Just made the change, will monitor this to see what happens, appreciate the help.

It's a relief to see that he was using AGI(...). I was starting to panic about this eventual bug.

The strange thing is that AGI works for 99% of the calls. It's an intermittent issue which is not fun at all. I have switched back to DeadAGI and will monitor this to see how it goes.

There is also a warning from * saying to switch to AGI instead of DeadAGI on the console.

I'll keep you guys posted. I should be able to tell in a few hours or so.

It's not truly intermittent; when using AGI() it affects all calls where the callee clears down before the caller.
You could use the search function here on that phrase if you want to learn more about the situation.

When using AGI, if the channel is hung up, than the PHP script is forced to stopped even if there were some unfinished business.

With that in mind, depending on which channel has launched the AGI script, the script will be kill if that channel is closed. So if the called party hangs up before the caller, things will be ok. But if the caller hangs up first, than the billing will not be correctly completed.

When using DeadAGI, the script will be allowed to continue its execution after line line is hung up. That allows a2billing to do some clean up stuff and keep everyone happy.

Cheers

- Well, it's been a few hours and things are working as expected using DeadAGI.

- A couple of things to keep in mind. When using AGI, as I previously mentioned, there were several test calls where I personally made sure the called party disconnected first and the calls were correctly registered. I performed lots and lots of tests before posting the issue. It happens as I mentioned previously intermittently at least in my platform and this is in both cases, caller and called party hanging up first.

Thanks guys for all the help, really appreciate it.