Open door with DTMF


Wondering if someone hit the same situation and might guide me here.
I have the GSC3570 setup as a SIP client on a Mobotix T25 camera.
The Mobotix is setup as an “External Service” on GSC3570. Type “Other”.

Mobotix accepts DTMF codes for several things like:
1 - Open Door
3 - Switch courtesy light

Issue #1
When I call from the Mobotix to the GSC I can go the the virtual keypad and send 1 to open door or 3 to switch light. It works well.
I did assign those same DTMF codes to the doors on the “External Service” specification. But when I press the door soft buttons, nothing happens. It’s like those virtual buttons are not sending the DTMF code. Is this the expected? Or am I doing something wrong?

Issue #2
If I call from the GSC to the Mobotix, neither the door soft buttons neither the keypad trigger any of the actions (open door or switch light).
Why does it work (at least the keypad) when call is established from the Mobotix but not the other way around?

Thank you


What firmware version if your GSC3570? Do both device configured DTMF payload correctly matched?

Issue 1: The virtual button is designed only work with Grandstream device like GDS37xx, because private protocol used for security purpose. When GSC3570 as callee, the normal DTMF open door kick in therefore works. But when GSC3570 as caller using Virutual Button, the private procotol kick in therefore NOT working. But you using dialpad from GSC3570 to calll Mobotix, or using “Speeddial” instead of Virutual Button, then I guess it should also work. Otherwise you might need to open a HELPDESK ticket and submit the packet trace to support to see whether this is a bug.

Issue 2: For GSC3570 as Caller but not working, you need open HELPDESK ticket with packet trace so the support can see what is going on between the wire. When you do this, please configure GSC3570 by enable the “SYSLOG” becuase the syslog will include lots of usefor information for troubleshooting.

GSC3570 is designed mainly to work with Grandstream Door Controller. For 3rd party device like Mobotix, untill full IOT testing done, not fully working is something normal. Grandstream device never work well with other vendors like Cisco, Ploycom, etc., untill all the parties involved finished the IOT testing and revised their firmware.

Thank you for using Grandstream Access Control Products.



Thanks for your prompt reply.
I’m using the latest firmware. I understand what you are saying about using proprietary protocols, but my understanding of the manual let me believe that DTMF codes could be sent to non Grandstream devices.

But I’ll do as you say and open a ticket to get this double checked!

Thanks again


The “Virtual Button” for 3rd party device previously working (like 2N Door System) in GSC3570, but unfortunately broken in recent firmware Bug already filed and will be fixed in next firmware cycle. Please keep tuned.

Thank you for using Grandstream Access Control Products.