VoIP/ATA + Hardware questions

I shortly expect to get FTTP and plan to port the BT number to Sipgate. We currently use DECT phones.

We don't make many outgoing calls on the line, mainly receive incoming ones. And the users would like to keep using handsets not soft phones.

However, I don't know what equipment I need in terms of an ATA etc.

1. I have a VMG8924. Could I connect that to my new ISP provided FTTP router and just use its voice port for the DECT?

2. Is something like the Gigaset N300 useful? Would that replace my existing DECT base and enable me to associate my existing phones to it?

3. What about other ATAs? I have often seen Grandstream mentioned?

Ideally, it would be good if the solution received voice calls via Sipgate (i.e. free) but allowed calls to be made over another VoIP provider who might be cheaper for those..

Are there any sites with good VoIP hardware reviews?

The N300A IP is a great device ... run 6 different VoIP services through it along with up to 6 DECT handsets. Your current handsets may work with it (or should) but with potentially a slight loss of finctionallity.


So, you can have Sipgate for incoming calls and another for outgoing - I do.

In reply to a post by gt94sss2:

1. I have a VMG8924. Could I connect that to my new ISP provided FTTP router and just use its voice port for the DECT?

You should be able to with no issue. I'm not familiar with the router in question, but it should be simple to do - either using double NAT (connect WAN port to a LAN port on your ISP router - not ideal) or by configuring the router on your LAN and you could also use it as an additional wireless access point if you wanted.

Once the config is done, should be simple to connect your existing DECT using a RJ11 to RJ11 cable or BT jack to RJ11 converter box (about £3 from ebay)

I use a Zyxel router (ISP provided) and my many years old Gigaset triple handset with SIPgate and it works great!

I would add that the VMG8924 VoIP doesn't work if the router is configured and connected via its LAN ports as the VoIP internal ATA is wired into only routing over the WAN side. Connecting a LAN port will work as an Access point when DHCP is turned off and a fixed free LAN IP address is configured on the router, but the VoIP will not connect to anything.

I have had its VoIP work behind a router by connecting the WAN port to my pfSense box and delegating an IPv6 subnet and NAT IPv4 address (configuring the VMG8924 for IPoE), which did work, although I think that was because it had a public and reachable IPv6 address. In my opinion, it's a lot of effort to get it to work and draws a lot of power just for VoIP use and I never found it was 100% reliable (would crash and stop receiving calls needing the VMG8924 to be rebooted).

The Yealink DECT base stations and phones are another good option. It is better to get a base station with its matching new DECT handset as that way you have full access to the various VoIP features, such as missed call and voice mail indicator, the ability to pick lines to dial out on (when more than one SIP account is configured), caller ID and address book access to name some. If you try and use an older DECT handset with a different base station, it may not work at all, or if it does, we often lose all features except for the basic functions of answering a calling and dialing a number.

Edited by E300 (Tue 16-Aug-22 13:15:18)