Shared lines get busy signal

[jcampbell]

I have a situation where we occasionally get a busy signal on IP phones with a shared line even though the phones are on-hook. The shared line is the only one that gets the busy signal. The user can still dial out on the line; they just can't receive calls. We have to reset all the phones with the shared line to fix the problem.

This problem started occurring after we went from 4.12 to 4.13sr1.

They only seem to occur with phones sharing a line and the phones are registered to different call managers.

Any suggestions would be helpful.

[thomas.chen]

Check the Busy Trigger value configured for these phone lines. Number of calls this line can receive = Highest Busy Trigger configured for this shared line - Number of calls on this shared line

[jcampbell]

They are set to 1 but that shouldn't make any difference if all the phones are on-hook..

[maharris]

It sounds almost like not everybody knows all of the phones are on hook, maybe a status change is not getting replicated occasionally? Do you have any errors on either the switch ports or the server interfaces?

Mary Beth

[jcampbell]

No errors appear anywhere. You just reset the phones and they go back to normal. I have checked ports, call manager sql replication errors, interface errors, etc.. They all appear to be normal. I just know when you move them all to 1 call manager the problem does not re-appear later on.

[maharris]

OK, you will hate this idea, but I think what you need to do is make sure your trace level is set to detailed, and grab a trace from both servers when you make call attempt that results in an erroneous busy, and then post them back here. We should be able to see what is happening. Does this happen to internal callers too, or just on calls coming in from outside?

Mary Beth

[bhattacharya.s]

Not sure whether this is a bug with 4.1.3 Sr1 or not, but I think the best option here is to check replication between the Callmanagers again. As you say, that as soon as u register all the phones to the same CM, things work properly, so I would think there is something else goin on here.

Run DBLHelper and reinitialize the replication and then check the results. I would also recommend changing the max no.of calls on the shared lines to be increased from 1.

And like Mary said, setup detailed CCM traces and call that shared line fron inside as well as outside and then post the traces here.

Lemme know how things go.