Firmware for DP752/750/760/730/722/720 released as official



Dear Grandstream Customers,

Firmware for DP752/750/760/730/722/720 is now released as official. Here is the link to the release notes:

The firmware and release notes can be downloaded from:

Please contact us should you have any issues. Thank you for your support for Grandstream products.

Technical Support
Grandstream Networks, Inc.



Has the problem of “Refer-To Use Target Contact” been resolved?
I don’t see it in the document


there is nothing updated in excepted a new CPE file (for RT069) that will better support our GDMS. other than this, everything is identical with

It is recommended to upgrade to in order to use our GDMS which is going to launch pretty soon.


Okay, thank you @Shawn-GSSupport424 ,
I hope that the problem of “Refer-To Use Target Contact” what I think is very important will be solved as soon as possible, customers call me every week to ask me if there is anything new.


I have same problem as @damiano70. New call drops after pressing call button. Error is “Cant find cmbs_channel by call Instance 0”.


I don’t have your problem @FabioW , I just reported that the “Refer-To Use Target Contact” function doesn’t work
(and it still doesn’t work)


Thanks @damiano70. I have the dp750 and dp752 and after use for few days, transfers or conference fail. After power down (not reboot), works again.


hello Damiano,
I found this could be your UCM settings. In order to display the transferred phone number, you need enable “Send Remote Party ID”, which is under PBX Settings -> SIP Settings -> Tos.
I tried my office extension with GXP and DP, both device enabled “Refer-To Use Target Contact”, however, both devices attended (announced) transfer the call to another one, the Caller ID was not updated. After enabled this option on UCM, it works fine now.

I also tried some other server like Kamailio SIP Server, my extension works fine for “Refer-To Use Target Contact”.

Could you try change the settings of your UCM see if the problem resolved? thanks!


hello @Shawn-GSSupport424
unfortunately it doesn’t work, as you can see from the screen (anyway on UCM it’s something I always enable).
For this problem I also opened a ticket, they had found the problem and told me “with the next fw will be fixed”, since then at least 2 fw have passed but the problem remains.


Here is my setting:

you know what, after I disabled “Refer-To Use Target Contact” on both GXP and DP, but enabled “Send Remote Party ID” on my UCM. Both device can update the CID correctly after announced transfer.

So my test steps are:

  1. I use my cell phone called GXP.
  2. use GXP to announced transfer to DP, the DP will display the GXP extension at first, after GXP transferred my cellphone to DP, DP should update the CID as my cellphone. This was not working before I checked “Send Remote Party ID”. This will work even I disabled “Refer-To Use Target Contact”.
  3. I tried call DP first, and announced transfer to the GXP, the result is also working fine.


my office UCM is UCM6208 V1.4A, and it’s using a newer internal firmware that’s later than the official I’m not sure if UCM team have added some fix recently to fix this issue, and don’t know when they will release the next new firmware.
But I think the Refer-To contact does not work is because of UCM, because me and my test team tried Kamailio SIP server and it works fine.


I believe you, you’re always helpful and kind, I only bring back my proofs, and even though I had enabled everything as you say, it didn’t work.
Now, unfortunately, I don’t have any DP at hand and I can’t rehearse.
If some reader in the next few days had the will and time to rehearse …


hi @Shawn-GSSupport424,

below are my tests carried out with:
I enclose DP752 and UCM, settings screen and photo showing that after the trip “201” remains displayed instead of the original external number (347xxxxxxx)


it doesn’t seem to be working properly,