Softswitch connection problem

[Ichimaru]

Hi everyone.

our 3cx connects to a Softswitch with a prefix, then it connects to the outside world with another prefix.

to connect to the Softswitch, we use prefix 9191
from Softswitch to the outside - 77

So in idea, I need to dial 919177xxxxxxxxxx.

I created a sip trunk with the IP address of the Softswitch, created an outbound rule (i'll provide the screenshot of the outbound rule).

no matter how I dial - there is always the error 403.

any ideas or did someone had to solve similar problems?

 

[cobaltit]

So if the softswitch needs 77 and you use 9191 to reach the softswitch why would you strip 6 digits? By my math you'd want to strip 4 digits so the 77 is sent to the softswitch with the dialed number.

 

[Ichimaru]

Tried it. striping 4 digits and even not striping at all.

sip trunk has basic configuration, without any special parameters.

maybe the next question might be quit, silly, but, can the SBC and Proxy be the problem?

They are on a separate trunk, but we are calling with that number, through the Softswitch.


I know, sounds really weird, but I did not build this topology

I'll provide a screenshot from Wireshark

 

[JohnS_3CX]

Start the other way round.

Who is giving you 403? - The softwitch? the next node upstream of the softswitch? Trace the whole path
Why are they giving you 403? - Tracing the whole path should give an indication

Once you establish those facts, you need to change the 3CX trunk accordingly, so the other side will accept your request. This is just general advice of course.

Also your screenshot shows that 9191 was sent in the invite, which I guess is invalid for the softwitch. It expects to see the number starting from 77 only. Not from 919177 as in your above screenshot