This topic

Smart Hub 2 - REN value

yorkley — Mon, 11 Dec 2023 16:12:55 GMT

A simple question that is not in the specification and nobody appears to know the answer.

What is the REN of the telephone port on the rear of the Smart Hub 2?

If nobody knows a definitive answer can BT Tech support please find out.

Cheers

Re: Smart Hub 2 - REN value

Keith_Beddoe — Mon, 11 Dec 2023 16:19:24 GMT

People have connected existing extensions with multiple phones, without any issues. Most modern phones need very little ringing current.

See https://community.bt.com/t5/Home-phone-including-Digital/REN-values-on-Digital-Voice/m-p/2312672

Re: Smart Hub 2 - REN value

yorkley — Mon, 11 Dec 2023 16:46:52 GMT

Very sorry, but that link does not answer the question. The people in the link are using adaptors or REN boosters.

This is a simple question - what is the REN of telephone socket on the rear of the Smart Hub 2.

It should be in the spec, but isn't.

Re: Smart Hub 2 - REN value

iniltous — Mon, 11 Dec 2023 20:24:28 GMT

Surely the REN is attributed to the device plugged into the SH2 , not the SH2 itself , and it’s only if you intend to use voice re injection and a ‘network’ of wired extensions , each with a device connected , that the cumulative REN may be needed to be observed.

If the total REN is not to be exceeded ( so you can be confident each device will ‘ring’ when an incoming call is received ) the maximum REN number for the UK networks is ( was ) 4 , that could be 4 devices each with a REN of 1 , or 2 devices with a REN of 2 etc ( generally a wired telephone has a REN of 1 ) .

TBH , unless you have a myriad of ‘old school’ devices with a electro mechanical bell sets connected, instead of ‘modern’ devices with electronic ‘ringers’ , it’s unlikely the SH2 won’t be able to handle the ringing current requirements of the devices hard wired to it , in that respect REN is a somewhat redundant term , and what’s more, if you connect too many devices and encounter ‘ringing’ issues , that’s your problem not your providers

Re: Smart Hub 2 - REN value

yorkley — Mon, 11 Dec 2023 21:31:57 GMT

You hit the nail on the head.

REN 4 for the UK networks.

This is a Smart Hub 2 and not the UK network. This device provides the ringing and therefore has a maximum REN.

This would have be stipulated in the specification.

Can you please advise on the REN the device will support.

Re: Smart Hub 2 - REN value

licquorice — Tue, 12 Dec 2023 08:15:23 GMT

This is a customer to customer forum, nobody here can answer that question. BT don't provide any specifications for the hub, you will just have to use trial and error.

You will not get a definitive answer however many times you ask.

Re: Smart Hub 2 - REN value

yorkley — Tue, 12 Dec 2023 09:03:43 GMT

Thank you for the answer.

With that in mind, how can I contact BT technical Support to ask them this question.

I can find no easy access to that group.

Re: Smart Hub 2 - REN value

licquorice — Tue, 12 Dec 2023 09:15:52 GMT

Which part of 'you will not get a definitive answer' was it that you didn't understand.

Re: Smart Hub 2 - REN value

iniltous — Tue, 12 Dec 2023 09:30:11 GMT

You didn’t know the specifications of the line card of the ‘exchange’ that delivered ‘ringing’ to your telephone instruments prior to the change to DV , so it’s not likely you will be given any information regarding the specs of the SH2 ringing current just because you want it , but more importantly, what do you want this information for ?
You can have a reasonable expectation that 4 wired devices each with a REN of 1 will not present an issue .

Have tried 4 devices ? is ringing compromised, is it that your ‘setup’ is fine with 3 devices, but fails with 4 (hence your question) ? , even in that case , it still falls into the realms of your problem, as the telephone instruments are your property , and it’s unverified if they have a REN number , or even if they do , are they within ‘spec’ .

TBH , if this is some sort of academic exercise or idle curiosity, no residential ISP is likely going to indulge you and provide information that is not relevant to you using the service they provide.

Re: Smart Hub 2 - REN value

yorkley — Tue, 12 Dec 2023 12:27:53 GMT

Put it this way. If I bought a car with no indication of seating capacity I would ask.

I would not try to see how many people I could squeeze in!

Some sort of question but different product.

Re: Smart Hub 2 - REN value

iniltous — Tue, 12 Dec 2023 15:49:59 GMT

To continue your analogy, you are changing your car for the same make and model just a newer version, there is no reason to suspect the new car cannot seat the same number of people as the old one , but you want the actual dimensions of the seats ,

Re: Smart Hub 2 - REN value

Colin_London — Thu, 14 Dec 2023 13:01:21 GMT

Is it not reasonable to just plug your devices in with a multiway adaptor and see if they still ring?

If you need more wired phones than supported, use a digital voice adaptor to connect them.

Given most people using DV will have DECT handsets, the multi phone capability of the Smart Hub 2 phone socket is a, well, ‘niche’ interest. If you use multiple DECT Handsets then you can actually make more than one call at once on a number - something you cannot do with a load of old handsets connected to the same port on the smart hub.

Re: Smart Hub 2 - REN value

JB2016 — Sun, 17 Dec 2023 22:07:40 GMT

@yorkley

https://bt-digital-voice.blogspot.com/p/bt-smart-hub-2.html

Re: Smart Hub 2 - REN value

fosterl2 — Fri, 17 May 2024 16:48:13 GMT

I was an apprentice at the time, but REN (Ringer Equivalent Number) numbers came into existence when PO Telephones first allowed people to connect their own devices to the network - part of the introduction of sockets (circa late '70s early 80's), rather than hard wired phones. Phones back then had a bell set and associated coils to operate it, and the the bell circuit was wired in series, whereas phones are in parallel. Due to the current drain of the bell sets, it was determined that a max of 4 (I think) was all that was permitted, due to the power drop in each bell set.

Modern devices do not use the bell circuit - they just sense the incoming ringing current, then electronically make a ringing noise, so then REN number is now totally superfluous and you can have as many devices connected as you like.

Re: Smart Hub 2 - REN value

Colin_London — Fri, 17 May 2024 20:32:34 GMT

Unless you are a fan of old school handsets of course (although they would still need to be DTMF as loop disconnect is no longer supported).

Re: Smart Hub 2 - REN value

Jane2018 — Sun, 19 May 2024 17:28:27 GMT

(Ah yes, I remember when there was that limit. Eg my father, a doctor, had a phone by the bed for night calls and one downstairs in the 60s and that was quite rare that we had two phones in the house. Then suddenly there were no restrictions and I ended up here with 4 upstairs and 3 down - 7 different rooms (until I culled it down to phones just in one room last Autumn in anticipation for end of 2023 digital voice which (thank God) has still not happened in this bit of London).

Re: Smart Hub 2 - REN value

Tim123 — Sun, 19 May 2024 23:05:32 GMT

If REN was only relevant to telephones with bells, how come even modern corded models (still on sale, such as the BT Decor 2200) still display "REN: 1" on the base?

Re: Smart Hub 2 - REN value

JB2016 — Mon, 20 May 2024 09:12:56 GMT

@Tim123 When the REN concept was introduced, the value of 1 was the lowest allocated. That remains the case today irrespective of the actual current demand of the particular telephone.

Further detail on current demand here: https://bt-digital-voice.blogspot.com/p/bt-smart-hub-2.html