Inbound calls drop after 30 second

mosalah73

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External calls work fine, although incoming calls from outside disconnect after 30 seconds of starting the call
 
Please ensure that your firewall is configured properly, and the firewall checker is not reporting any errors. This is important, as it is possible that due to a network misconfiguration that there is no proper communication between the PBX and the provider and after no acknowledgement after 32 seconds, the call is being dropped.

This might be due to port forwarding, SIP ALG or port preservation.
 
Please ensure that your firewall is configured properly, and the firewall checker is not reporting any errors. This is important, as it is possible that due to a network misconfiguration, there is no proper communication between the PBX and the provider and after no acknowledgment after 32 seconds, the call is being dropped.

This might be due to port forwarding, SIP ALG, or port preservation.
The communication between PBX and the provider is good and there are no errors on the firewall, I have other trunks with other sites that are working fine without any problems with inbound or outgoing calls.
 
Is the firewall checker passing with 0 errors?
 
You could do a capture on an outgoing call to see if the PBX is sending the correct contact information to the provider. Namely you will be looking for the proper IP Address and SIP port of the PBX in the contact field. If it is sending it correctly and the provider is not sending an ACK back to the PBX, after 32 seconds your call will drop.

This is either due to the network being misconfigured or something on the providers end.
 
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You could do a capture on an outgoing call to see if the PBX is sending the correct contact information to the provider. Namely you will be looking for the proper IP Address and SIP port of the PBX in the contact field. If it is sending it correctly and the provider is not sending an ACK back to the PBX, after 32 seconds your call will drop.

This is either due to the network being misconfigured or something on the providers end.
The outgoing calls are working fine, the problem is with incoming calls as I mentioned before.
 
Exactly.

An incoming call sends an INVITE.
The PBX when the user answers the calls sends a 200 OK that the call has been answered and waits for an ACK
If that ACK doesnt come the session closes.

Has a capture been done? Are you seeing the entire call flow?

Could you please give us a screenshot of the firewall checker result?
 
Exactly.

An incoming call sends an INVITE.
The PBX when the user answers the calls sends a 200 OK that the call has been answered and waits for an ACK
If that ACK doesnt come the session closes.

Has a capture been done? Are you seeing the entire call flow?

Could you please give us a screenshot of the firewall checker result?
after i capture the date i know where the problem is
The contact header IP contains my Private IP Address (10.1.1.14 ). As the provider is required to send the ACK back to the IP Address in the Contact header, the ACK is being sent out to that Private IP Address. Since Private IP Addresses are not publicly routable, the ACK never reaches your SIP Infrastructure, so the call times out on that end and is torn down
so how can i solve this problem i need to resolve my private IP with the public in the contact header with incoming calls
 

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In your provider settings you should be able to configure this to show the proper IP Address

1737453796903.png
 

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Which provider is it? Did you use the correct template?
 
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Which provider is it? Did you use the correct template?
provider is Twilio
after i modified the templet it's not working still have a private ip in the sip header message
 

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Sounds like a NAT or firewall issue. Try checking your firewall settings, make sure SIP ALG is disabled, and double-check your NAT settings. Also, take a look at the 3CX logs to see if they show why the call is dropping.
 

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