Outbound call disconnects after 10 seconds

[Alphabetic]

**After checking it's not specifically 10 seconds**

3CX Prof 16.0.1581 4SC
Debian ISO - Hosted in cloud
Firewall check - Passed
Handset - Yealink T27G 69.84.0.95
Prov Meth: STUN
SIP Provider: Unsupported
Custom Templates: No

Hi All,

I've had this installation in since 15.5 with the same SIP and we've had no problems up until recently. Updates are automatic every weekend.

EXT makes a call out and at some point (not the same each time) the call will drop.

SIP provider have sent a screenshot showing that 3CX sent a BYE on these calls that drop.

Have not been able to capture anything from 3CX yet.

This is not on every call out.

Any advice would be great.

thanks.

 

[eddv123]

SIP provider have sent a screenshot showing that 3CX sent a BYE on these calls that drop.

The system is hosted in the cloud, but is it public facing or behind a software firewall ?

Prov Meth: STUN

How many STUN phones are we talking about on this single site ? and are they configured correctly (port forwarding/statically assigned IP addresses etc).

If you can replicate easily run a PCAP capture yourself from the 3CX interface and see what is going on.

 

[Alphabetic]

The system is hosted in the cloud, but is it public facing or behind a software firewall ?



How many STUN phones are we talking about on this single site ? and are they configured correctly (port forwarding/statically assigned IP addresses etc).

If you can replicate easily run a PCAP capture yourself from the 3CX interface and see what is going on.

It's public facing and they have 3 STUN devices and i've given them static IP / port forwarding.

Just trying to get customer to make tests.

 

[eddv123]

3 STUN devices is not ideal but I cant see it being a major issue especially if you are going public facing (which I dont advocate due to security restrictions).

I had a similar issue recently with a software firewall (OPENSense) it was the provider leg however where the firewall passed the checker completely, the provider was saying it was the firewall configuration.

We changed to a PFSense and configured the same and it worked first time with no issues since.

 

[Alphabetic]

Ok so far all I have is what the VOIP Provider has sent.



that doesnt look right receiving so many BYE does it?

 

[eddv123]

VoIP I assume is the provider network/SBC IP address.

I can see that there is no RTP stream after the ACK however this might not be the case if this is the leg between PBX and provider (as RTP is most likely being sent directly).

If RTP is present (like you say for 10 seconds) the BYE looks to be getting sent from your end, which I would say is most likely your router/firewall device (for example the port being cut-off).

I think it maybe likely (especially due to the use of STUN) that there maybe a port mis-match. For example if you check the preceding messages (in the Contact header for example) do they match?

Just a thought as a test also you might want to try traffic using TCP if the option is available.

 

[Alphabetic]

Sorry no, voip is the SIP Trunk to 3CX. This is the trace the sip provider sent me on this particular call.

I've started a continuous wireshark capture on the PBX and im waiting for him to report to me a problem so i can look at that.

 

[JohnS_3CX]

Best collect some more data if possible, and see what the STUN phone does.

Perhaps the PBX ends the calls due to losing the leg to the STUN phone?

 

[Alphabetic]

(╯°□°）╯︵ ┻━┻

I thought id have a look and it turns out I hadnt done any forwarding or anything. This was an early installation back in t' day. Im gonna set that up now and see how it goes.

 

[JohnS_3CX]

Putting the proverbial ACL table back then.. ┬──┬◡ﾉ(° -°ﾉ)

 

[Alphabetic]

Putting the proverbial ACL table back then.. ┬──┬◡ﾉ(° -°ﾉ)

I just cant cope this week with the level of humour in this forum. I even put the guy (he's called Harold) in my signature because its too funny.. now he has a friend. Im going to start a petition to get these table flippers in the emoji list.

 

[eddv123]

Sorry no, voip is the SIP Trunk to 3CX. This is the trace the sip provider sent me on this particular call.

Yes so provider edge to the 3CX system, this is what I meant, but it did not include the leg from phone to PBX.

As with the above (as I am sure you know) port forwarding is key, see the diagram I posted in my first post, shows the configuration from a Draytek device.

 

[Alphabetic]

So, got a capture. Customer said they rang the same number again and it happened again but when the other party called back there was no problem.

My capability of being able to interpret wireshark data is laughable so any advice is great.





There's a BYE at 196.269173 - can someone tell me what that is?



Other then that. From what I can see the BYE comes from the SIP provider :S

Just some additional info. This user uses the 3CX Windows App to initiate calls to desk phone (dialling from address book).

 

[eddv123]

If OK feel free to PM across to me, but let me know the details of the call if possible.