Thank you, Yvgeni, I've got it working. I configured the site (not the default one) associated to the incoming PSTN trunk with the number plan and call route, and it works without touching the default site though.
Original Message:
Sent: 06-09-2026 07:45
From: Yvgeni Liberman
Subject: Sending calls to another ORG
Sandor,
I have the same configuration PSTN --> My Org --> SIP Trunk --> Remote Org.
The calls are coming to My Org from PSTN (BYOC Cloud SIP Trunk), from My Org I have SIP Trunk (BYOC Cloud to BYOC Cloud) to the Remote Org
In my default site, I created the Numbering Plan (only for 3 DIDs) that "forwards" all incoming calls to this trunk to the Remote Org.
In the Remote Org, I created a Numbering Plan that sends all outgoing calls to the My Org and from it to the PSTN.
This is the screenshot of the Trunk Configuration from My Org side:


This is the screenshot of the Trunk on the Remote Org


------------------------------
Yvgeni Liberman
Solutions Architect
Mobile +972 52-6344414
Voice +972 3-9281514
e-mail yvgeni_new@itnavpro.com
------------------------------
Original Message:
Sent: 06-09-2026 06:28
From: Sandor Balogh
Subject: Sending calls to another ORG
Hi Yvgeni!
I looked at the documentation, but it is a bit ambiguous for me: Configure PBX passthrough for a BYOC or External SIP trunk - Genesys Cloud Resource Center
My setup is: PSTN -> BYOC SIP trunk -> ORG1 -> Inter-ORG SIP trunk -> ORG2
My understanding is, that I need to setup the BYOC SIP trunk as a "Generic BYOC PBX" to allow calls to be routed to other SIP trunks (any). Is this correct? I am hesitant to do so, as it will open my ORG1 for toll-fraud.
Which Site configuration will be used? I originally assumed that the one I set on the trunk for transfers would be used, but the above article confused me. "As a best practice, Genesys recommends that you not enable the PBX passthrough feature on BYOC Cloud trunks that are associated with multiple sites. The reason being that inbound calls route to any of the potential sites without predictability. "
Alternatively, if the following is true, "PBX passthrough requires that either the inbound or outbound trunk must be a PBX trunk. PBX passthrough between two carrier trunks is not supported." I can simply create a new InterORG trunk as a BYOC PBX, and a site routing only the required numbers to that trunk. Do you think that would work?
------------------------------
Sandor Balogh
-
------------------------------
Original Message:
Sent: 06-07-2026 02:52
From: Yvgeni Liberman
Subject: Sending calls to another ORG
Sandor,
It's simple,
You must define "PBX Passthrough" in the trunk:
and "Number Plan" on site, for example, like this

And Routes
If You need more information, please contact directly to me
------------------------------
Yvgeni Liberman
Solutions Architect
Mobile +972 52-6344414
Voice +972 3-9281514
e-mail yvgeni_new@itnavpro.com
------------------------------