The SH2 needs to be directly connected to the phone socket/ONT for digital voice. I did mine this way:
Smart Hub 2 (SH2) router settings:
Turn IPv4 DHCP off. (The addresses here are best set as static addresses but you can use dynamic addressing if you really want).
Set IPv6 DHCP to ‘Stateless’.
Set the router itself to a static IP of 192.168.1.254 and a subnet mask of 255.255.255.0 or /24. (These settings are its defaults, so you may not need to change anything).
Set the DMZ host to 192.168.1.2 (This helps with double NAT problems or at least it takes care of the port forwarding on the SH2. There is still address translation happening, however, so you may still have problems with multiplayer games, UPnP etc. In fact, you only really need this if you allow unsolicited incoming external connections for a server or remote access etc. Personally, I’ve never found double NAT to be an issue and I don’t use the DMZ setting. If you do use it, note that that it weakens your security slightly by allowing a lot of traffic to effectively bypass the SH2 firewall, so you are relying on your own router’s firewall for security, just as if it was directly connected to the internet).
Turn off the Wi-Fi in favour of your own router. (This may also be a good security move if you do enable the DMZ host. I would still expect Wi-Fi traffic on the SH2 to go through its firewall but I can’t be sure how they’ve set it up internally).
Connect the DSL port to the phone socket on the wall or the WAN port, (port 4), to the ONT, whichever is applicable. If the latter, don’t forget to also enable FTTP Mode on the SH2. (Again, this is usually on by default).
The DV phone/extension then plugs into the green phone socket on the SH2.
Own router settings:
Turn the IPv4 DHCP on. Set the range to 192.168.0.2 - 192.168.0.200 (Note the 0 in the third position, making this a separate network to the SH2. This is deliberate, not a typo. You can use another number if you want but not 1).
Set IPv6 to DHCPv6 Client.
Set the router itself is on a static IP of 192.168.0.1 and subnet mask of 255.255.255.0 or /24, (if using static addresses. If dynamic, set it to get an address automatically).
Enable the (E)WAN port and set it to a fixed IP of 192.168.1.2 (This makes your router’s WAN port part of the SH2 network).
Set the gateway to 192.168.1.254 (Again, pointing to the SH2).
And also set DNS to 192.168.1.254, (or whatever you usually use).
The EWAN socket on your own router, (probably no.4), then connects to a LAN port on the SH2. (NB. This will not work if you use the DSL port on your own router).
Any static addresses on devices in your own network will also need to match the network address of 192.168.0.x If you’ve used the range I suggested above, that means the x will need to be 201 or above.
(Lastly, if your own network already uses 192.168.1.x, it might be less work to set the SH2 to 192.168.0.254. Of course, this effectively reverses the use of 192.168.1.x and 192.168.0.x throughout the above).
