Calls over generic sip trunk use RTP port range 7000

[DidierDE]

We notice that calls over our SIP Trunk use RTP ports in the range 7000. Why is this?

Normally ports in the 7000 range are for internal calls, or am I wrong? I would think that a range of 9000-10999 would be used here.
This is a SIP trunk to our voice gateway which then connects to our provider.

 

[NikosT_3CX]

@DidierDE your destination is a private ip so the port range here is correct.
The range of 9000-10999 is for VoIP Providers that are public ones.

 

[DidierDE]

that is indeed the internal interface of our voicegateway. I did not know that 3CX uses the ip address to decide if it is an internal or external call. I would think that anything going out of the pbx through a sip trunk is an external call...
Is there a way to set the port range in the provider template?

 

[NikosT_3CX]

@didierCH the PBX detects and distinguishes the IP addresses based on RFC 1918 for private and public ones.
In the template this can not be set as this is a PBX functionality and not a VoIP Provider one.
The range that will be used here from the PBX side is 7000-8499 UDP.
Setup this UDP range in your L3 device ( as I can see they are in different subnets ).

 

[DidierDE]

I understand. We have used other brands of PBX's, and this is the first time I encounter this. All PBX's that we used just use the standard RTP port range 16384-32767, regardless of the ip address of the remote device.

Maybe it could be an option to add a checkmark in the SIP Trunk options to flag a trunk as external.