Kitz Forum
Broadband Related => Telephony Wiring + Equipment => Topic started by: snadge on December 28, 2018, 04:33:33 PM
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I am looking to replace my NTE5 with a Filtered Faceplate and just wondering if there are some filters better than others?
I recall someone saying (years ago) that the ADSLnation XTE designed filtered faceplate is an 'Active' type and these are not as good as 'Passive' types such as the Pressac VDSL Mk4 faceplate.. I dunno if this was true? I have read on Wikipedia that 'Active' types may be considered better?
https://en.wikipedia.org/wiki/DSL_filter#Components
can anyone shed some light on this?
thanks
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The first question that you should answer is: Do you intend to use the circuit for telephony?
If your answer is "No", then do as Weaver and do not install a centralised splitter/filter. If your answer is "Yes", then use an Openreach branded NTE5/A and Mk 3 SSFP.
Don't use "historic" "ADSLnation" items. The company ceased to exist some years ago and old stock is still being sold-off. Those "XTE" devices were designed for ADSL2+ and not for the wider bandwidth of VDSL2.
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The first question that you should answer is: Do you intend to use the circuit for telephony?
If your answer is "No", then do as Weaver and do not install a centralised splitter/filter. If your answer is "Yes", then use an Openreach branded NTE5/A and Mk 3 SSFP.
Don't use "historic" "ADSLnation" items. The company ceased to exist some years ago and old stock is still being sold-off. Those "XTE" devices were designed for ADSL2+ and not for the wider bandwidth of VDSL2.
run-it-direct sell ones that look the same as those XTE ones, call them VTE I think?
I do intend to use a phone, i dont use it but its nice to have in emergency
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I'd recommend an OpenReach MK3 SSFP if you have an NTE5A master socket.
If you have the newer rounded NTE5C them buy an OpenReach MK4 that fits the newer master sockets.
I don't recommend any of the other faceplates currently on run-it-direct.
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I'd recommend an OpenReach MK3 SSFP if you have an NTE5A master socket.
If you have the newer rounded NTE5C them buy an OpenReach MK4 that fits the newer master sockets.
I don't recommend any of the other faceplates currently on run-it-direct.
he only sells the Mk4 with NTE5C or the XTE design, the rest are discontinued, i will just get one off ebay or that 5C at some point
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I'd recommend an OpenReach MK3 SSFP if you have an NTE5A master socket.
If you have the newer rounded NTE5C them buy an OpenReach MK4 that fits the newer master sockets.
I don't recommend any of the other faceplates currently on run-it-direct.
if u dont use a filter.. does a modem have a high pass filter built in?
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Every modem has a high-pass filter in its input stage.
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The first question that you should answer is: Do you intend to use the circuit for telephony?
If your answer is "No", then do as Weaver and do not install a centralised splitter/filter. If your answer is "Yes", then use an Openreach branded NTE5/A and Mk 3 SSFP.
Don't use "historic" "ADSLnation" items. The company ceased to exist some years ago and old stock is still being sold-off. Those "XTE" devices were designed for ADSL2+ and not for the wider bandwidth of VDSL2.
I'm confused by your statement that ADSLNation is bad because VDSL2's wide bandwidth. Do you have any scientific evidence to back up your claims? I thought the role of a filter was to filter out telephony signal, rather than broadband signal. Really confused now.
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The can be filters that either block or pass low frequencies, high frequencies or a band of frequencies. (In that one sentence I have covered six separate scenarios.)
A simple, rat's-tail, microfilter will just have a low-pass filter before the telephony port and nothing before the xDSL modem port. All modems (modem/routers) have a high-pass filter internally just before their analogue front-end.
Centralised filters (service specific face plates (SSFPs) in Openreach talk) will contain a combination of low-pass, high-pass and band-pass filters depending upon the service for which they have been optimised.
Those old ADSLnation centralised filters were designed for ADSL/ADSL2+ as that was only what existed "back then".
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Pretty sure mine was an ADSL Nation ADSL v1, was absolutely fine on VDSL until it eventually failed.
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Pretty sure mine was an ADSL Nation ADSL v1, was absolutely fine on VDSL until it eventually failed.
Cheers. What were the 'symptoms' of your failedADSL nation filter? However, our line has intermittent interference and also a bad joint, which openreach are not fixing (I'm sorry to say but openreach are the worst company I've ever dealt with. There should be more competition on the market and should be allowed to go bust.).
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Cheers. What were the 'symptoms' of your failedADSL nation filter? However, our line has intermittent interference and also a bad joint, which openreach are not fixing (I'm sorry to say but openreach are the worst company I've ever dealt with. There should be more competition on the market and should be allowed to go bust.).
I can't remember exactly, I think it might have stopped getting sync at all.
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The can be filters that either block or pass low frequencies, high frequencies or a band of frequencies. (In that one sentence I have covered six separate scenarios.)
A simple, rat's-tail, microfilter will just have a low-pass filter before the telephony port and nothing before the xDSL modem port. All modems (modem/routers) have a high-pass filter internally just before their analogue front-end.
Centralised filters (service specific face plates (SSFPs) in Openreach talk) will contain a combination of low-pass, high-pass and band-pass filters depending upon the service for which they have been optimised.
Those old ADSLnation centralised filters were designed for ADSL/ADSL2+ as that was only what existed "back then".
I'm confused about this. The consensus on this forum seems to be that a filter is there to separate voice to enable one to use voice services. As Weaver repeatedly said (and others repeated), there is no need for a filter if you're using broadband only. So, logically speaking, does it matter if it's MK3, 4 or ADSLNation? It shouldn't, unless you have some research to prove otherwise.
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The primary purpose of the filter is to block the xDSL frequencies from the voice side of the circuit. How efficiently this is done and how much loss there is to both the xDSL and voice signals depends on how well the filter is designed. Noting here that no filter is totally loss free.
As has been said there is no need for a filter if you are not using a voice service on the line and with no filter there will be no loss.
:)
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As I understand it there is no loss on the xDSL side as that is an unfiltered direct connection, it is only the phone side that is filtered.
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Also that difference in how well they filter can apply to avoiding noise escaping back from the voice side into the VDSL frequencies. The mk3 upwards for example filter the bell wire.
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I had an old ADSLNation faceplate when I 1st got VDSL2 in 2011.
I eventually switched to an MK2 and saw an improvement in sync speed.
The MK3 synced even higher.
Imo the ADSLNation faceplates are old and not really fit for purpose on VDSL2.
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I've used ADSL Nation, MK3, MK4, none of them made any difference at all on my lines though I'm currently on a MK3.
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As I understand it there is no loss on the xDSL side as that is an unfiltered direct connection, it is only the phone side that is filtered.
In a perfect filter that would indeed be the case, but none are perfect. The xDSL loss will be very small but I believe there will still be some, and if you're trying to eke out every last bit of the signal like @weaver then no filter at all is preferable.
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I don't use a phone so I am considering not using the Microfilters (rat's tail).
The only problem I'd have is converting what I think is an RJ11 connector to the flatter-thinner connector in the wall.
Would I use something like this: https://www.tvcables.co.uk/bt-plug-rj11-socket-adapter.html
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Would I use something like this: https://www.tvcables.co.uk/bt-plug-rj11-socket-adapter.html
Yes, that should do the job. (Or you could source a lead with the appropriate plugs at either end.)
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tubaman is correct. I’ve never managed to measure any difference between all the really top ones and any of them vs none at all. The good ones that I have used are (note ADSL-only) ADSL Nation one and the BT Pressac type ones. The latter are excellent. The ADSL Nation active ones are good but perhaps more relevant in the case where you have other kit such as one or more telephones attached also. Top tip: absolutely do not have other kit such as one or more telephones attached also. And remember that these observations were made with ADSL2 only and with an ultra-sensitive setup, because it’s with ultra-long lines in use, approx 4.55 miles long, hence an ultra-weak signal received ( ~64 dB attenuation downstream). (Too many ‘ultras’ [ed.])
Indeed getting rid of telephones and extensions helps you get the very best out of your line. That’s always what you should do unless you’re absolutely forced to have a telephone on the same line.
I refer you also Burakkucat’s warning earlier about not using these abovementioned filters with FTTC/VDSL2 lines. They’re only for ADSL2 lines. Those old ADSLnation centralised filters were designed for ADSL/ADSL2+ as that was only what existed "back then".
For ADSL, the ADSL Nation’s advantage is that it’s cleverly designed to cover up the differences between the on-hook and off-hook situations so that you should not see any transient problems when you transition between the on- and off-hook states, or have DSL performance problems while you are on the phone.
For FTTC/VDSL2 lines, use no filter, unless you for some reason have to have a telephone on the same line. If you do have to have a telephone then I strongly recommend following J0hn’s advice: I'd recommend an OpenReach MK3 SSFP if you have an NTE5A master socket.
If you have the newer rounded NTE5C them buy an OpenReach MK4 that fits the newer master sockets.
I agree with J0hn and much prefer the NTE5A/Mk3 SSFP from Openreach (optimal solution), preferred by both me and J0hn over the modern NTE5C/Mk4 SSFP - the one with rounded corners. The NTE5C/Mk4 SSFP combo disconnects without screws, which is nice, but they don’t seem like a very secure fit.
I myself ended up with one NTE5C+Mk4 SSFP, the new Openreach installation default, after a recent line installation, unfortunately. I was initially forced to have an unnecessary SSFP that way, which is bad. And that was my fault for not sitting there watching the engineer’s every move like a hawk. I immediately wanted to get some help in order to follow J0hn’s recommendation and put it back the way it was, with an NTE5A+no filter.
If you don’t have to have a telephone, then hallelujah: you can also get a perfect solution, which is an Openreach telephony-only NTE - not sure exactly what it’s called, and no filter. This Openreach package comes as an NTE5c back-box, I think, but with a telephony front lower-half plate that has a BT telephone socket / old UK dialup modem socket in it. Then to make it work you just need an old-fashioned dialup-modem cable that is UK-BT-phone plug (into wallsocket) to RJ-11 plug (modem end).
Cables and plugs: Some dialup modems did come with a cable that had UK BT plugs on the end, perfect for the above solution, apart from usually being way too long for the typical modern use-case where we want the cable to our modem to be short to keep interference to a minimum. Carefully read the spec for the dialup-modem cable though, as some dialup modem cables do however come with the wrong, so-called ‘US’ plug, ie RJ-11 plugs on both ends. So watch out. The RJ-11 sockets were sometimes called ‘american modem sockets/plugs’ back then.
I should ask the grumpy old cat what the correct technical terms are for the plug types needed?
I would prefer getting a lead made up that has the correct plugs in it as it’s going to hopefully be more robust and be cleaner than the above converter plug, which is however fantastic value. I got someone on ebay iirc to make up cables for me with the right plugs on them. Could even look at Amazon shops maybe. Getting a custom-made one you can have it exactly the right length, can specify high-quality gold-plated plugs on it of the type you need, and high-quality twisted-pair BT CW1308 cable used by Openreach for doing phone extension cables. This latter is very important. It’s also important, mainly with ADSL, to keep the cables short, just long enough to reach the modem as this minimises interference pickup within the home/office. Mine are ridiculously short, 0.5 / 1.0 / 2.0 m as short as we can get away with. If you have a separate modem and router, which is a great idea, then you can keep the modem near to the wallsocket and make the modem-router ethernet cable as long as you like.
So coming back to plugs: depending on which of the various solutions above you choose, you need either an RJ45-RJ11 cable, or a dialup-modem-to-UK-BT-phone plug.
To be honest, with VDSL2 none of the micro-optimisation things such as NTE / SSFP choice, or cable length or whatever is going to make much difference to performance. It’s especially unimportant (too many negatives, [ed.]) if you’re using FTTC/VDSL2 and you’re very close to the FTTC ‘green cab’, because a very short line means a strong signal received at your end, and you are much, much less sensitive to interference including interference pick-up within the home/office even, because your received signal voltage at your line will be comparatively really high, so large compared to any local in-house noise.
If you’re using ADSL, then every little thing matters, how much depending on how long your copper phone line is from the exchange.
But if you have an interference problem in your home or office where your wallsocket-modem cable is picking up RF noise, make sure you are using CW 1308 cable, keep it short and keep it well away from mains cables and any electrical equipment. If you have to cross a mains cable, don’t, but if you have a gun to your head, cross the cables at right-angles and try and keep the two well spaced apart. Try relocating cables and kit. Do not run mains cables and modem cables parallel alongside each other, or worse parallel close together and worst of all touching.
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I refer you also Burakkucat’s warning earlier about not using these abovementioned filters with FTTC/VDSL2 lines. They’re only for ADSL2 lines.
Surely it makes absolutely zero difference as a DSL filter is designed to only let voice frequencies through, so what is going on outside those frequencies is of no consequence.
I used the ADSL Nation filter right up until it broke, many many years on VDSL. I think the one I had dated from plain ADSL days, not even ADSL2.
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> Surely it makes absolutely zero difference as a DSL filter is designed to only let voice frequencies through, so what is going on outside those frequencies is of no consequence.
Indeed, that’s what’s supposed to happen. I will defer to others here as a know zero about VDSL2/FTTC.
I seem to remember that Openreach engineers were supposed to upgrade NTEs when they did a VDSL2 installation, but maybe I got this wrong. The idea being that the earlier filters filtered off some very high frequencies, be it accidentally or by design. It could be for some reason these earlier NTEs were choosing to filter off frequencies that were too high and could never be used by ADSL2. I think that ADSL G.992.1 - 8 Mbps - was treated the same as ADSL2 G.992.3 - 12 Mbps back then in filter design, fortunately. Again, maybe my memory fails me on this point. Filtering out impossible frequencies is helpful in many cases where inadequate input filtering is in place and perhaps this was either known to be true with some modems, or judged as a possibility worth guarding against, belt and braces style.
Digression: my audio power amplifier in the early 1990s, an Audiolab, was found to have a hardware bug in it. Amps that were connected directly to CD players, particularly certain models, were found back then to be generating noise which I think was misbehaviour of the front end reacting badly to unexpected high frequencies coming directly from the CD player. I forget all the details, it may have been that if the usual model of preamp was in use then that covered up the problem. However people like me had no preamp just a passive volume control connected between the CD output and the power amp. A board was released to fix the problem. The problem was confirmed to be the presence of unexpectedly high frequency noise coming out of the source and because the power amp input could not handle this, it should have been gently pre-filtered off.
Was it Burakkucat, only a possibility, who once said something like "The wider one opens the window, the more muck/dirt flies in ?" ;) Or it may have been Gilbert Briggs. It was the kuro neko’s approach to ADSL2, which I enthusiastically followed being already familiar with the window-opening philosophy.
So anyway, I just assumed at the time that in the old NTE5s some low-pass filtering may have been going on at really high frequencies, way outside the audio range and then some. And as I’ve suggested, maybe a feature maybe a bug. If any of this earlier story is right it was presumed to be necessary for Openreach to swap out older NTEs and I assumed that this had to be because they were bandwidth-limiting. Oops.
And yes, you’re of course right in that it’s not supposed to be like that. Any window-muck determination should be solely done by the front end of the modem, which alone knows its own requirements for anti-muck protection if any.
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So anyway, I just assumed at the time that in the old NTE5s some low-pass filtering may have been going on at really high frequencies, way outside the audio range and then some. And as I’ve suggested, maybe a feature maybe a bug. If any of this earlier story is right it was presumed to be necessary for Openreach to swap out older NTEs and I assumed that this had to be because they were bandwidth-limiting. Oops.
Shouldn't matter though, as only the phone socket is filtered, the DSL socket is directly wired. I do not believe the DSL side was touched until the much later ones with REIN filters which on a line not suffering REIN could actually degrade the signal a little.
No doubt this has been posted on here before:
https://www.youtube.com/watch?v=jD67a-ZC7VY