2 x DP720 (handsets) with a DP750 base, doenst always ring both handsets




I am sure i have seen the same problem listed here before…

I have a DP750 and 2 x DP720 handsets, all are latest firmware (, i have 2 accounts on both hand sets, if a call arrives (from outside), it appears to be random IF the handset will ring at all.

I never saw this problem when there was only 1 handset, it only started once i had 2 on the same base.

There set to ring in parallel, as i mentioned above, it will sometimes work (mostly when its tested) but 20-30% of the time one of them wont ring, at this point i dont know if its BOTH, so, does the DP750 log what calls it received to see if theirs a network issue?


Possible fix found:

Turns out this extension that was prevision on to many handsets was set to Circular and not Parallel… ive not tested it yet but i assume its fixed.


I have (4) DP750’s and (18) DP722 with firmware on a Yeastar S50 PBX.
The DP722’s can always make a call but randomly can not receive a call. I setup a call group for all 18 phones and called them and randomly 5-6 of them will not ring. The capture file shows that the extensions that don’t ring are busy. I’ve spent a week working with support and no fixes yet. Anyone have any thoughts?

None of the SNOM phones on the PBX have the issue.

  • I assume you have 5x722 on each of the 750’s?
  • Do each of the 722 have there own extension number?
  • What is the signal strength of each of the 722 handset?
  • Manually configured each 750 with a single Profile?
  • Manually configured 5 extensions in the 750 and assigned to a single handset per extension?


All of the 722’s have their own extension numbers
I’m currently testing the system before I install it for the client so all of the handsets are in the same room as the DP750’s. I thought maybe the signal strength might be too strong so I moved the DP750’s to opposite corners of the room (Approx 12 feet apart).
All of the handsets on each DP750 are on the same profile1 and there is only Profile1 is configured.


To simplify this request a bit… i opened a ticket with Greandstream… as far as i am concerned, if the PBX calls a number (on VoIP trunk) and hears a fax machine the other end, it can (well at least should) do either:

  • Make the call and route sounds to the requesting extension (if its a FAX this would likely be T30)
  • Make the call, realize its a fax and convert any internal T38 protocols to T30:

It can clearly do this as it CAN send faxes, i just cant find the "look at stream, if T38 then convert to T30), which i will add IS ON the FXO connectors, its called “Fax Gateway” and only appears to be on the digital to analoge connectors (FXO / FXS), which is fine, but creates an issue when the VoIP trunk connects to a fax outside… !!!

Would think this is simple, however i am still waiting for Group Voicemail to be fixed from 5 years ago !!!