Any incoming call drops after ~ 32 seconds

[century-it.co.uk]

Hi

Hope someone can help me; We have a 3cx box that has a problem with incoming calls. The call drops after about 32 seconds. This happens on the SIP trunk and analog VOIP box on the same Local Area Network as the phone system.

Any suggestions would be very welcome

Rick

 

[Alphabetic]

Is this all incoming calls?

Put your 3CX in to verbose logging, restart services and make your test call.

Run a wireshark capture and see who's sending BYE

 

[century-it.co.uk]

As a follow up the log is showing this when the call disconnects;

08/09/2020 12:00:13 - [CM503021]: Call(C:26): ACK is not received from sip:[email protected]

 

[Alphabetic]

See if this helps:

https://www.3cx.com/community/threads/ack-is-not-received.62434/

 

[JohnS_3CX]

This is a typical SIP timer limit, and you may be in a situation where the ACK message is not received from the other side even though the conversation has started.

If this ACK is not received, then the other side will end the session after 32 seconds when it times out

 

[century-it.co.uk]

Hi John,

Thanks for the reply, so in real world terms what do I have to change / config to receive the ACK ?

Rick

 

[JohnS_3CX]

Hi Rick,

Please give us some basic info first. Read here:

https://www.3cx.com/community/threads/information-to-provide-when-requesting-help.67558/

 

[century-it.co.uk]

Hi Rick,

Please give us some basic info first. Read here:

https://www.3cx.com/community/threads/information-to-provide-when-requesting-help.67558/

• CX Version, PROFESSIONAL Perpetual 16.06.641
• Server OS, Windows 10 v2004
• Is the 3CX Server Hosted and where? No Local installation
• IP Phone Make/Model/Firmware Yealink T28P v 2.73.0.60
• Provisioning Method: Local
• Trunk Provider or Gateway Make/Model Spitfire VOiP / Patton 1 Analog line
• Has the Firewall Checker passed: NO
• Are custom Phone Templates being used: NO

 

[JohnS_3CX]

Ok so you are running an analog land line from Spitfire, over a Patton?

What model is the Patton, its it within the supported range?
https://www.3cx.com/voip-gateways/

If so, did you set up using the above guides?

 

[century-it.co.uk]

Ok so you are running an analog land line from Spitfire, over a Patton?

What model is the Patton, its it within the supported range?
https://www.3cx.com/voip-gateways/

If so, did you set up using the above guides?

Hi John,
Thanks for the reply.

It's a Patton SN4112/JO/EUI it's been working flawlessly for at least 5 years. Bear in mind the same problem on the Spitfire VOiP SIP trunk. The problem only occurs on incoming calls, outgoing calls are fine.

Rick

 

[eddv123]

Although you have said that it occurs on both trunk types (FXO and SIP)- if you want to further investigate the Patton (it has very detailed logging) you can SSH into it and run the following:

enable
configure
debug ccfxo
debug fxo
debug call-control
debug call-router
debug context sip-gateway transport
debug context sip-gateway error

To turn off debugging (if you turn it on) : no debug all

A Wireshark would be good to see however: https://www.3cx.com/docs/capture-network-traffic/ I am not sure about Spitfire but some providers (Twilio for example) give the options of pulling PCAP traces from provider side also - as a techie having this feature is priceless.