Calls are dropped after 15 and 30 minutes

[roger.schmid.503]

Hi all

We have installed a 3CX PBX about 2 months ago and are using the following installation:

- Operating System: Windows 2008 R2 in an VMware environment
- 3CX Version 11 with all the actual patches
- Colt is our SIP Provider
- A patton H.323 Gateway is added for H.323 support
- The PBX is installed in the NAT-Environment and has a private address
- We are using SNOM 821 phones with the latest firmware 8.7.3.19


I modified the following parameters on the SNOM 821 phones:

- Timer support in SIP/RTP is off now
- SIP Session Timer is set to 10800 (3h)

Some parameters in the 3CX PBX:

- Reinvite and replace are off now
- the advanced parameter MaxCallDuration is set to 10800 (3h)

We have the following behaviour on calls:

- Incoming SIP-calls are dropped after 15 minutes
- Outgoing SIP-calls are dropped after 30 minutes
- Incoming and outgoing calls on the H.323-trunk work fine (no drop)

I have played around with the parameters (reinvite, MaxCallDuration, and the settings in the SNOM 821 phones). The result is still the same. Incoming Sip-calls are dropped after 15 minutes, and outgoing after 30 minutes.

I captured the calls with wireshark (see the attachments) and after analysis I was able to see that the SIP "bye" command always comes from the Snom phone (IP:234). Everything works perfectly on the H.323 trunk.

Due to the fact, that wireshark tells me the call were ended correctly, I don't think that there is a firewall problem.

Does anybody have an idea on where the problem could be located and how to fix this?

Any help is very much appreciated

Roger

 

[mic.max]

Are you provisioning snom phone from 3cx? Post your phone configuration.

 

[roger.schmid.503]

I have made some additional tests over the weekend. I have tested our 3CX system with a Cisco and Aastra SIP-phone. Exactly the same things happened. An outgoing call is dropped after exactly 30 minuten and and icoming after 15 minutes.

The wireshark capture says, the "BYE"- command comes from the phones. That doesen't make sense to me. I didn't provision the Cisco and the Aastra phone from the 3CX and both phones had the latest firmware.

Any idea how to get rid of the problem?

Thanks in advance

Roger

 

[a-hernandez]

I'm using Yealink phones but was having a similar situation.
I decreased the registration time , cannot remember to what number but I think it was less than 15 minutes

 

[roger.schmid.503]

Thanks for the tip. Where did you change that? On the phone side?

Thanks

 

[roger.schmid.503]

I tried your suggestion today

I Set the reregister on the snom to 720 seconds (12 minutes), but the situation is still the same. I get a BYE from the phone after 15 and 30 minutes.

 

[complex1]

If you try another phone and the problem stay the same, then I think you should look into 3CX or your SIP provider.

What about if you make an internal phone call for say 31 minutes will the phone also disconnect after 15 or 30 minute?

Maybe if you bypass 3CX and make direct calls to / from the Snom the calls last longer?

 

[roger.schmid.503]

I have tried it with a Cicso and Aastra phone. The line is still dropped after 15 min (incoming) and 30 min (outgoing).

Today i made an internal call from one Snom to another Snom. No problem at all. The line was stabil and i hung up after 53 minutes

I am going to talk to the SIP provider Colt tomorrow.

 

[a-hernandez]

Sorry for the delay.

My registration time (login expire on Yealink) is setup to 300 seconds. Give it a try

 

[roger.schmid.503]

No problem, I am happy for every tip. I have tried on two phones (Snom and Cisco) with a registration time of 300 seconds. The line is still cut after exactly 30 minutes.

 

[eagle2]

This should be some parameter in the phone called session timer or session expire timer, usually in seconds, i.e. in your case 900 or 1800 seconds value. After expiring the timer the phone will drop the call.

 

[lneblett]

Orlin, true, but if that is the case, then would it not stand to reason that he would not have been able to conduct an internal call for 53 minutes?

 

[complex1]

Today i made an internal call from one Snom to another Snom. No problem at all. The line was stabil and i hung up after 53 minutes

Roger you never answered my question what happened if you bypass 3CX how long the calls then take?

If the line still dropped after 15 min for incoming and 30 min for outgoing calls then you should contact the provider Colt because the problem is not caused by 3CX or the used phones.

If the line dropped within 15/30 min then the problem is (maybe) caused by the phone.

 

[cobaltit]

@complex1

I have tried it with a Cicso and Aastra phone. The line is still dropped after 15 min (incoming) and 30 min (outgoing).

Today i made an internal call from one Snom to another Snom. No problem at all. The line was stabil and i hung up after 53 minutes

I am going to talk to the SIP provider Colt tomorrow.

He did try an internal call which didn't have the issue, so it seems to point to an issue with the provider

 

[complex1]

I know, but you can only be sure if you also make a phone call directly connected with the provider bypassing 3CX.

When the duration of the call is 15/30 min then the problem lays at the provider side. But what about if the duration of the call is longer than 15/30 min? Then you have to search or the setting in the phone or 3CX.

Sorry, but English is not my native language so it is hard for me to discus with you.
Hope you understand this.

 

[roger.schmid.503]

I tested it with a phone using the provider directly. The same happenend.

I had a colt-technician on the phone for several hours and we found the reason for the cut calls. The sip provider sends a "INVITE" command every 15 minutes and the technician said the provider doesn't get a "ACK" on that. Well he switched the "INVITE" after 15 minutes off and now the calls work fine in both directions.

Thanks to all of you for your help

Roger