Own router and digital voice methods

Switching to Zen FTTP next month with digital voice so trying to work out how to get all this plumbed in and set up in advance.

Currently on FTTC with an Asus AC86U (running Merlin) connecting via PPPoE to the openreach modem.
Several wireless repeaters in the house, separate guest networks and VLANs for IoT devices and so on.
Inbound forwarded services are things such as backup DNS, Backup MX, Wireguard and OpenVPNs and so on.

In short, i really cant afford to lose these or reconfigure absolutely everything on the FritzBox so want to use the existing router and infrastructure.

If i didn't want digital voice it would be a simple case of plugging the router in and configuring the PPPoE but the problem is digital voice (dect and analogue port) will be needed.

Im assuming there's no such thing as an adaptor to plug into the existing router to allow the functionality?

Assuming i need to use the FritzBox plugged into the ONT as a first hop then what's the easier way to preserve my current network whilst getting digital voice?

Can it be configured dumb with DHCP and everything turned else off and in the same subnet as my existing LAN so i just change the default gateway on the WAN interface of the existing router?

Would it be better or even work configured as a slave with wifi etc disabled plugged into the existing router?

In short what would be the easiest, least obtrusive way to keep my current LAN setup with FTTP and the digital voice?

Ive got the 7530 manual and going through it but it isnt overly helpful here.

Ideally, if i have to use the FritzBox in the setup, i want it to be as invisible and unobtrusive as possible.

Would "configure as an ip client" be the best option? ( https://en.avm.de/service/knowledge-base/dok/FRITZ-B... )

Im comfortable with the networking but not in how digital voice authenticates and works.


Thanks

You definitely need the Fritzbox in the chain. Zen don't supply the necessary SIP details and they will no doubt be encrypted.

The easiest way is to go Fritzbox > Router.
You would need to disable DHCP on the Fritzbox or put your router in a DMZ but the Fritzbox would still be doing the PPP.
It isn't ideal.

BT and Sky do similar and users have worked out how to put their respective hubs "behind" their own router by tricking the hubs in to thinking they are running the connection.
So it's ONT > Your router > BT/SKY Hub.

The BT hub guide is posted here

I can't find the Sky guide right now but it's done different but with similar outcome.

If you're smart enough and can use wireshark you may be able to work out how to do similar with the Fritzbox.

I use a Granstream HT802 ATA which just plugs into my switch. The telephone wiring also plugs into the same unit. It was all fairly painless, just had to plan and buy the correct additional extension wiring etc.
As for VOIP supplier, I used Sipgate, but as they no longer do a "free" offering, there are now cheaper elsewhere.

In reply to a post by Adduxi:

I use a Granstream HT802 ATA which just plugs into my switch. The telephone wiring also plugs into the same unit. It was all fairly painless, just had to plan and buy the correct additional extension wiring etc.
As for VOIP supplier, I used Sipgate, but as they no longer do a "free" offering, there are now cheaper elsewhere.

He's specifically asking about Zens own VOIP/Digital Voice service.
You can't use an ATA with this.

Sadly that's not an option with the Zen Digital Voice (and i dont want a SIP provider as cant afford to lose the landline number)

Cheers - was hoping i could not have to use the Fritzbox but looks like i can.

I guess the only way to do it is the messy option of Fritzbox with WiFi, DHCP and everything disabled and DMZ to the old router. Fritzbox having a fixed LAN ip in my current subnet.

That or the "IP Slave" the manual mentions. If that works it would be a better option.

Main problem i have is i've never seen the kit in my life and there's a high chance i'll have to talk someone through the setup of this on the phone as i wont be around. Tricky when you've never seen the equipment and going by PDFs as to how it should work.

In reply to a post by String:

Sadly that's not an option with the Zen Digital Voice (and i dont want a SIP provider as cant afford to lose the landline number)

You should be able to transfer your landline number to a SIP provider. However, that will also cease your broadband connection (so you may end up with penalty charges for early termination etc.). Worth looking into as you get towards the end of your broadband contract.

In reply to a post by j0hn83:

He's specifically asking about Zens own VOIP/Digital Voice service.
You can't use an ATA with this.

Ahh, I wasn't aware of that. Oh well, every day is a school day !

In reply to a post by j0hn83:

You definitely need the Fritzbox in the chain. Zen don't supply the necessary SIP details and they will no doubt be encrypted.

You can decode FritzBox data using stuff from https://github.com/PeterPawn/decoder

I've just tried copying the scripts https://github.com/PeterPawn/decoder/tree/master/scr... to a linux box and using the decode_export script on a configuration file exported from a FritzBox.

This worked successfully on an ex-Zen device repurposed for other use with providers (CIX broadband & AAISP VoIP). I can't see that a Zen-provisioned device would be different unless they can lock down what is included in the export, but it really needs someone with Zen Digital Voice to confirm this.

Zen have had a SIP platform for some considerable time and they used to provide connection details, but you were pretty much on your own getting working if there were any issues. Most of the old help / knowledgebase information appears to have gone but there is some in the refreshed help pages https://www.zen.co.uk/help-support/general-sip-settings

If their Digital Voice offering is the same platform underneath it may be that as with other providers they don't want to provide credentials to reduce support queries, etc., but you can configure a third party device having obtained the required information.

To set up Zen DV as just another SIP provider you can set the server address(es) to voip2.zen.co.uk, set your DV phone number as the user ID, and get the voip password here:
Zen customer portal / My Services / General / select Digital Voice / show VoIP password
This works for me on my Gigaset N300A DECT base, connected to the internet, although I usually use the normal Zen procedure, connecting to the Fritz box FON port with the fixed line connection from the N300A.

Edited by cjn (Thu 16-Feb-23 14:21:36)