sip ip changes

[bashrael]

Hi,

we have a sip provider with ip 85.119.188.3. We can make calls for 10-15 minutes and then we get a 'forbidden' message when calling out.
I contacted the sip provider and he says we are sending our request to the wrong ip(85.119.188.2)
I dont understand where the 85.119.188.2 comes from....log:


Anyone an idea what could be causing this?
The 3cx is hosted on google cloud.
If I refresh my sip trunk everything works again for 10-15 minutes.
thanks!

 

[JohnS_3CX]

I don't know what your exact trunk configuration is, but you can try going to its options and enable "Force Invites to be send to IP of Registrar".

Let us know if this helps.

 

[bashrael]

Hi,
that option is already enabled. issue remains
grt

 

[JohnS_3CX]

It would be a good idea to register your trunk and capture a successful call, and then when it stops working capture a failed one with the forbidden response so they can be compared.

Also does your sip trunk have a proxy defined or is it blank with only the registrar hostname filled in like the screenshot below?

 

[bashrael]

Hi,
Yes I did test that. Ip doesnt change when the call is successful.


sip trunk is the same like on your screenshot.
grt
bashr

 

[JohnS_3CX]

@bashrael if you like you can Generate Support Info files and upload them somewhere and send me the link in a PM so we can take a look at your setup (without changing anything, just as it was when the problem appeared)

 

[Rhys Haskell]

A lot of sip providers use a different IP for the signaling and for the RTP. This may be causing the issue that you are experiencing. If you look at the RTP stream does it come from 85.119.188.2?

 

[bashrael]

Disabling the option
"Force Invites to be send to IP of Registrar".
solved this for us but I still don't understand what was causing this

 

[JohnS_3CX]

If that solved it for you, then take a look at the last paragraph in this link for an explanation:

https://www.3cx.com/docs/sip-trunk-dns-record-resolution/

In addition, its difficult to say more unless I can see your trunk's General tab and Outbound Parameters tab