Loading capacity of 'Digital Voice' ports on Routers

Has anyone any experience of how many phones the phone port on a router (such as the BT Hub, or Zen's Fritzbox) can actually support ?

I'm not expecting 1970s style vintage phones with real bells to work too well, but what about modern desktop phones ?

I ask, because my mother's extension network is equipped with three 'desktop' phones, and a DECT base station.

Will all that lot still ring when hanging off a 'DV' port (or indeed a 'proper' ATA ) ?

I think that your would just have to try to find out.

A Cisco SPA112 supports a max Ren of 5. If you know the REN figures for your mother's phones you could estimate whether they would all work. See SPA Specification. (SLIC Section)

Yes, but they would say that wouldn't they !

It'll be too late to find out it doesn't work once she is converted, hence my question if anyone has any real world actual experience yet ?

for BT's Digital voice offering - you could use the 'digital voice adapter' for corded phones. these look like a powerline plug type thing, but work over wi-fi and you plug your standard PSTN phone into it

In reply to a post by Dean83:

for BT's Digital voice offering - you could use the 'digital voice adapter' for corded phones. these look like a powerline plug type thing, but work over wi-fi and you plug your standard PSTN phone into it

Yes, it's a big house, and Wifi soon gets blocked, so that's not really viable. The house has an extensive wired extension network, which I installed 40 years ago, when I lived there, so I was hoping to carry on using that infrastructure.

A BT line only supports a max REN of 4. Both the Cisco and Grandstream ATAs claim to support a max REN load of 5.

You could find out what load the the BT Hub, or Zen's Fritzbox will support.

In reply to a post by Michael_Chare:

A BT line only supports a max REN of 4. Both the Cisco and Grandstream ATAs claim to support a max REN load of 5.

The regulations didn't allow any device to declare itself as less than 1, but electronic buzzers don't take anywhere near the old style REN designed for 1960s type mechanical ringers. In most cases you'll find connecting 10 or more handsets will all work, until you add 1 more and they stop ringing

I don't know whether this will help, but my Cisco ATA191 can ring 6 phones and similarly my Technicolor DGA0122 VoIP Port can also ring 6 phones.

When going over to VoIP I bought a Ring Booster https://vikingelectronics.com/products/rg-4/ but didn't need it. Although of USA manufacture, it passes UK standard CLI without a problem

Cheers!

In reply to a post by broadbandjockey:

Yes, it's a big house, and Wifi soon gets blocked, so that's not really viable. The house has an extensive wired extension network, which I installed 40 years ago, when I lived there, so I was hoping to carry on using that infrastructure.

40 years ago I had to pay BT an extra amount because there was extension wiring!

In reply to a post by Dean83:

for BT's Digital voice offering - you could use the 'digital voice adapter' for corded phones. these look like a powerline plug type thing, but work over wi-fi

They are DECT not WiFi - using a lower frequency, greater transmit power, plus completely different and more robust protocols so have a better reach.

Thanks Clive, that's the sort of info that’s useful.

Actually, I've just remembered our son has DV via Sky Broadband (which he never uses of course !). I'll take my box of old handsets and a load of 1x2 adaptors, and load up his Sky Router to see what happens.

My mum has 5 phones connected over re-injection (I know I did it after she was left with a router in the upstairs box room repurposed as a wardrobe closet of sorts). That was with BT. 1 is cordless and the rest are standard landlines (very old mounted to the walls). Installed by BT before they bought the house. The kind of phone that has no screen and over the years the cables become approx 3 miles long and can now reach the corner stop and back no problem. A sort of yellow tint to it that’s either age or just a preference for creamy yellow coloured phones in the 1970s/80s.

Pretty sure the phones will outlive me. They have a nice soothing ring. Like a very professional corporate office. You need one in each room to hear it ring.

Edited by ukhardy07 (Wed 29-Nov-23 09:41:17)

+ I can attest to the range of a cordless phone being far better than WiFi. Mine works in the car park through a block of flats over the walkway. My WiFi barely makes the entrance of that block.

I have a buddy who owns a farm, he’s got a BT Elements landline that claims 1KM range. It’s called “BT elements 1K.” He uses it in outbuildings etc.

In reply to a post by ukhardy07:

My mum has 5 phones connected over re-injection (I know I did it after she was left with a router in the upstairs box room repurposed as a wardrobe closet of sorts). That was with BT. 1 is cordless and the rest are standard landlines (very old mounted to the walls). Installed by BT before they bought the house. The kind of phone that has no screen and over the years the cables become approx 3 miles long and can now reach the corner stop and back no problem. A sort of yellow tint to it that’s either age or just a preference for creamy yellow coloured phones in the 1970s/80s.

Pretty sure the phones will outlive me. They have a nice soothing ring. Like a very professional corporate office. You need one in each room to hear it ring.

Ha, very good. One of my mum's phones is as you describe, the others are 'Big Button' Doros or Geemarcs !

In reply to a post by ukhardy07:

The kind of phone that has no screen and over the years the cables become approx 3 miles long and can now reach the corner stop and back no problem. A sort of yellow tint to it that’s either age or just a preference for creamy yellow coloured phones in the 1970s/80s.

Everyone should have one🤣

Nobody knows exactly how many vintage phones or modern phones can be connected to the router. I did a search on that on google and read that the ringing voltage and current, has to come from within the Smart Hub 2, so that is going to limit what you can connect to it, as its only a low voltage feed into the hub, and the ringing convertor circuitry is no going to be very powerful, and nowhere near what is outputted from the same analogue PSTN equipment in the exchange.

So the best you could do is experiment and connect using an adapter and see how many it can handle until it fails.

The only thing I know and you already probably know that you can connect up to 5 digital dect phones wirelessly.

I have tested with my old vintage style phone connected to the router and it definitely works and rings fine. But like many of us, most of us have abandoned the use of using landline phone. Most of us use mobile phones. So it is going to be difficult to find an answer on traditional phones especially since Digital Voice isn't yet widely used by all FTTC customers.

For example I disconnect the vintage phone manually from the router and only connect it when I need to since my old vintage phone doesn't have silent mode. So if someone does ring at night it will be a nuisance and wake us up. It only stays on the table as a souvenir.

But the wireless BT dect phone is far more convenient and you can put phone on silence and switch it off and add list of phone numbers, block calls if needed, etc.