603 decline when passing through SBC

[Thomas LAVIGNE]

Hi all,
This is my first post on this forum. I searched a lot but didn't found similar request.
I'm struggling with a 3CX setup. We decide to put a SBC (on rpi) in order to by-pass the ISP router that was causing trouble.

So I setup a rpi at home and tested with two test extensions and it worked for a few days.
Then I moved everything to customer side and was unable to place any call (603 decline).
The extension seems registered (on the phone and on the server) but can place or get any call.

I took everything back at home and had now the same issue. 603 decline on any call.

If I only change SIP server back to cloud server, it work.
As soon as it pass through SBC, I have 603 decline.

I've tested with a fresh install of the SBC but no change.

Please find here bellow pcap from the gxp2130 once while passing through the sbc and one connected directly to the server.

Please note that there is no trunk or sip provider. Only call between local extension.

Thank you for your help,

Thomas

 

[eddv123]

A 6xx style response is commonly a global error response. More specifically what you are seeing is a 603 DECLINE: The called party doesn’t want to or can’t take the call and the call will be disconnected automatically. https://www.3cx.com/pbx/sip-responses/

Have you checked the status of this extension you are trying to dial ? the phone can also generate this response if the user is using call screening. This type of response can indicate a better time to call in the retry after header field so if you are proficient enough please take a look here.

Alternately I would get the full verbose logging from the system, it may give more clues:
https://www.3cx.com/docs/collecting-logs-for-3cx-support/

 

[Thomas LAVIGNE]

Hello,
Thank you for your fast reply. I enabled verbose loggin on the server and got a few message while getting the 603 error.

01/27/2019 7:58:06 PM - [CM503013]: Call(C:100): Incoming call rejected, caller is unknown; msg=Invite-IN Recv Req INVITE from 127.0.0.1:5080 tid=2003780292 [email protected]:

01/27/2019 7:58:06 PM - [CM500002]: Unidentified incoming call. Review INVITE and adjust source identification:

I can put more of the log if necessary.

But I don' t understand why it is working without 3CXSBC. I was hopping sbc will help things to go smoother, not add a layer of complexity

Thank you for your help

 

[eddv123]

Without SBC, are you talking about direct STUN in that case?

If so then you still have the configuration for STUN on the phone(s) and I believe this maybe your problem.

To test between STUN and SBC are you swapping the setting on the extension or complete reprovisioning?

 

[YiannisH_3CX]

Hello @Thomas LAVIGNE

The first thing that you need to check is your IP blacklist. Once you made sure that the IP is not blacklisted check your Local SIP domain matches your FQDN. You can check this under Settings / Network / FQDN in the management console.
Also make sure that the phones are provisioned through PnP with the default 3CX templates.