Ntt Flets PSTN gateway

[Andriy]

I see. I guess i need to learn what wireshar is

 

[leejor]

It's a network analyser, that allows you to to see exactly what is happening (what is being sent back and forth), on your network. It includes tools specific to the SIP protocol.
https://www.wireshark.org/

 

[Andriy]

Thank you.
Will take a look at that. Does it also show what port numbers are used?

 

[leejor]

There are a number of sites with information on using Wireshark with SIP (and 3CX specifically), if you do some searches.

https://www.3cx.com/blog/voip-howto/sip-traffic-capture/

 

[Andriy]

Thank you leejor,
I will start learning about Wireshark