Ring Group not picking up

[ahren]

Here's a weird one a staff member reported back to me yesterday. She sits at a desk that consists of a ring group of 4 phones. A call came in, rang all 4 phones, but when she picked up her extension the call didn't answer and the other phones kept ringing. She had dead air on her line, not a dial tone. She had to hit *20* to pick up the other phone.

She says it happened to her twice that day, but other times it worked properly. Of course I didn't get a time of day, so I can't go back and look at the logs but here's the pertinent info:

3CX version 14
Cisco 7941 phones
Ring strategy: Ring ALL

I'm not expecting a miracle fix, as I know it's a weird intermittent issue, but maybe someone can clue me in on a likely culprit or suggest something specific to look at.

Thanks.

 

[leejor]

My first thought would be a faulty set that is not sending a message that it is off hook. If that were the case, she would probably experience more instances of no dial tone when placing calls. There still could be an issue, something that is triggered only when there is an incoming call. Until you have a chance to "catch" a log of one of the calls, you might try swapping out her set to see if the problem goes away. If it does, I would try a reset of the phone (be sure the firmware is up-to-date), then give it to someone else in the ring group and ask them to report if the issue returns so you can swap out again. If after giving the original user, a new set, and it still occurs, you may want to examine the network. Perhaps a faulty switch (port?) that that user is behind?

 

[ahren]

Thanks! I was also kind of wondering if it might be the actual physical phone. I'll swap it out and see what happens!

 

[daktur]

Have you tried to set the queue to priority ringing and put the first a ring group with the 5 extension and second a ring group with the other 2 extension?

I dont remeber being able to add a ring group to a queue but if it is possible this should be a nice try.

 

[ahren]

I swapped out the physical phone in question last week, so I'm going to follow up with staff and see if that made the difference. If not, I'll definitely explore that route!

 

[ahren]

Ok, my staff informed me that the problem persists. However, they gave me actual time and extensions when this happened so I could look it up in the logs! :O

What I found for incident they sent me was this:

08-Aug-2016 13:13:30.380 NAT/ALG check:L:2107.6[Extn] RESPONSE 200 on 'INVITE' - some of SIP/SDP headers contain inconsistent information or modified by intermediate hop
SIP contact header is not equal to the SIP packet source(IPort):
Contact address:192.168.106.71:5060
Received from :192.168.106.71:49156

Any ideas what this means and how to go about fixing it? Do you think it even has anything to do with the extensions in the ring group not picking up properly?

 

[leejor]

It may be the issue. What do you have (a device) on the network that could be seen as an intermediate hop? It would appear that the port number has changed from the port number that the set originally registered with.

Are the sets local, or...?

 

[ahren]

The sets are local. Our setup is pretty simple, the only unconventional thing I can think of is in order to bypass the 10/100 bottleneck of the Cisco 7941 phones I setup small desktop (unmanaged) switches to split the connections between the phone and the computer. However, I have another desk in a different part of the building set up as a ring group with the same configuration and we haven't had any problems there.

 

[leejor]

If you can duplicate the issue then during the weekend, or some other off-hours time. Move the set to another physical location, not behind the same switch. See if the problem move with the set, or could it be the switch it is currently behind.