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Standard User n21
(learned) Sat 10-Dec-16 16:19:34
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VDSL through ADSL v1.0 master socket?


[link to this post]
 
Hello! I just placed an order for BT Infinity and was given the option of self-activation. My concern, however, is the line I have has one of the 'older' ADSL v1.0 filtered sockets, installed by BT.

Is this an issue and would it affect performance? I should clarify that the line has no extensions and has no phones plugged into it—it is used solely for broadband.

Many thanks! smile
Standard User MHC
(sensei) Sat 10-Dec-16 16:31:37
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Re: VDSL through ADSL v1.0 master socket?


[re: n21] [link to this post]
 
It might have a small adverse effect as the earlier filters were not designed with the higher VDSL frequencies in mind. As you have no phones or extensions, a filter is not actually required and you could just use an appropriate BT to RJ adapter.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit
Standard User n21
(learned) Sat 10-Dec-16 16:34:36
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Re: VDSL through ADSL v1.0 master socket?


[re: MHC] [link to this post]
 
Oh right, that's a very good point. So I could actually just run straight off the test socket then if I wanted and bypass filters altogether, thereby attaining maximum possible line performance?


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Standard User MHC
(sensei) Sat 10-Dec-16 16:50:32
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Re: VDSL through ADSL v1.0 master socket?


[re: n21] [link to this post]
 
You could, or get a standard telephony only faceplate on there if you want it to look tidy.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit
Standard User n21
(learned) Sat 10-Dec-16 16:52:37
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Re: VDSL through ADSL v1.0 master socket?


[re: MHC] [link to this post]
 
OK, might look at that then, thanks! And to clarify, the new master sockets would offer no performance benefits over a standard NTE5?
Standard User MHC
(sensei) Sat 10-Dec-16 17:02:10
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Re: VDSL through ADSL v1.0 master socket?


[re: n21] [link to this post]
 
Provided there are NO telephony connections then a standard NTE5 will be te best choice. Even the newest VDSL filtered face plate could affect the performance. A filter is NEVER perfect.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit
Standard User 23Prince
(committed) Sat 10-Dec-16 17:04:22
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Re: VDSL through ADSL v1.0 master socket?


[re: n21] [link to this post]
 
I had a new line installed a few days ago - and the socket provided certainly has changed from the flat version!

https://s23.postimg.org/f9m7p6s7v/20161210_170225.jpg
Standard User n21
(learned) Sat 10-Dec-16 17:04:53
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Re: VDSL through ADSL v1.0 master socket?


[re: MHC] [link to this post]
 
Understood. Yeah, that's why we opted for a separate line. The main voice line in the house is extremely old, so the broadband line just comes straight in and terminates at the front door. From there, it hits the router and then Cat6 around the house.

Yes, no extensions and no phones plugged into the socket. The line has a call plan (because I think we have to with BT, unfortunately) but I don't expect that would make any difference haha!
Standard User 23Prince
(committed) Sat 10-Dec-16 17:06:59
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Re: VDSL through ADSL v1.0 master socket?


[re: n21] [link to this post]
 
2 weeks ago I nearly chopped what I thought was an old unused cable just swinging freely from the back door to the floor.

Just learnt it's the older existing phone line with the original FTTC on! Glad I didn't! :/
Standard User RobertoS
(elder) Sat 10-Dec-16 17:31:37
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Re: VDSL through ADSL v1.0 master socket?


[re: n21] [link to this post]
 
I don't think you have to have a call plan. I would check that out if I were you.

Re the router siting, how far will that be from the master socket, will a phone extension cable be used to reach it, and what were the Infinity speed estimates?

VDSL2 is much more sensitive to total line length from the cabinet, and phone extension cables can be a significant source of noise.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 60000/15199kbps @ 600m. - IPv4
Standard User n21
(learned) Sat 10-Dec-16 17:35:08
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Re: VDSL through ADSL v1.0 master socket?


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
I don't think you have to have a call plan. I would check that out if I were you.

Re the router siting, how far will that be from the master socket, will a phone extension cable be used to reach it, and what were the Infinity speed estimates?

VDSL2 is much more sensitive to total line length from the cabinet, and phone extension cables can be a significant source of noise.


Ah, the only option I saw was unlimited weekend calls which doesn't seem to cost anything.

As for the router, it's literally just 1m away. I have a very thick, shielded cable running between it and the master socket. From the router, devices and relays are connected via Cat6. As for the cabinet, I believe it is about 100m away from me. BT are estimating 80mbps down, 20mbps up which I believe is the maximum?

Edited by n21 (Sat 10-Dec-16 17:35:58)

Standard User MHC
(sensei) Sat 10-Dec-16 18:11:21
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Re: VDSL through ADSL v1.0 master socket?


[re: n21] [link to this post]
 
In reply to a post by n21:
In reply to a post by RobertoS:
I don't think you have to have a call plan. I would check that out if I were you.

Re the router siting, how far will that be from the master socket, will a phone extension cable be used to reach it, and what were the Infinity speed estimates?

VDSL2 is much more sensitive to total line length from the cabinet, and phone extension cables can be a significant source of noise.


Ah, the only option I saw was unlimited weekend calls which doesn't seem to cost anything.

As for the router, it's literally just 1m away. I have a very thick, shielded cable running between it and the master socket. From the router, devices and relays are connected via Cat6. As for the cabinet, I believe it is about 100m away from me. BT are estimating 80mbps down, 20mbps up which I believe is the maximum?

80 Mbps and 20 Mbps ... appropriate capital make a lot of difference! m - milli; M- Mega



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit
Standard User eckiedoo
(fountain of knowledge) Sat 10-Dec-16 18:27:15
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Re: VDSL through ADSL v1.0 master socket?


[re: n21] [link to this post]
 
The ADSL and the VDSL sides of the devices, whether you call them splitters or filters; are actually "Straight-through".

The filters are in the PHONE side; and are High-Frequency Reject Filters/circuits, to prevent the ADSL/VDSL signals from being attenuated by the PHONE load.

(They could also be called Low Frequency Pass Filters/circuits.)


To put it another way, if you were to plug an ADSL/VDSL Router in to the PHONE side of such (newer) splitters, that Router should not see the ADSL/VDSL signals.


On the other hand, as the ADSL/VDSL side is straight-through, a conventional corded phone will work, as well as the router.


I have experimented with up to 5 such splitters/filters in series, in both configurations, confirming the above.

---------------

You should also carry out the Quiet Line Test, using a corded phone, to ensure that the actual phone line is up to scratch, as faults on it will generally affect ALL signals on it, whether DC, audio, ADSL or VDSL.

Both BT and SKY recommend the QLT early in their self-help information.
Standard User RobertoS
(elder) Sat 10-Dec-16 19:27:43
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Re: VDSL through ADSL v1.0 master socket?


[re: eckiedoo] [link to this post]
 
In reply to a post by eckiedoo:
The filters are in the PHONE side; and are High-Frequency Reject Filters/circuits, to prevent the ADSL/VDSL signals from being attenuated by the PHONE load.
I thought it was so the phone was usable. The racket DSL puts on the line would make it impossible to use.

The phone load between the filter and DSLAM/MSAN is a given.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 60000/15199kbps @ 600m. - IPv4
Standard User MHC
(sensei) Sat 10-Dec-16 21:19:29
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Re: VDSL through ADSL v1.0 master socket?


[re: eckiedoo] [link to this post]
 
In reply to a post by eckiedoo:
The filters are in the PHONE side; and are High-Frequency Reject Filters/circuits, to prevent the ADSL/VDSL signals from being attenuated by the PHONE load.

(They could also be called Low Frequency Pass Filters/circuits.)



Irrespective of how good they are, they will still have an impedance across the line at all frequencies - it may be high but will still take a small amount of signal and could alter the phasing. Some of the original ADSL filters could have been pretty bad once signals up in the MHz range were presented.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit
Standard User eckiedoo
(fountain of knowledge) Sun 11-Dec-16 07:58:13
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Re: VDSL through ADSL v1.0 master socket?


[re: MHC] [link to this post]
 
Agreed - that is why I included "(newer)", and hopefully not over-complicating the situation, by going in to impedances etc.
Standard User eckiedoo
(fountain of knowledge) Sun 11-Dec-16 08:48:27
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Re: VDSL through ADSL v1.0 master socket?


[re: RobertoS] [link to this post]
 
Morning Robertos

I have just re-tested that aspect.

The NTE is an ancient simple one, single outlet, no filters of any variety, so normally goes in to a VDSL Splitter, with an Ethernet cable to the Bright Box modem/router; and all the traditional, higgledy-piggledy phone wiring, accrued over almost half-a century.

The NTE is downstairs relative to the EE Bright Box 2, so I could not readily observe its LEDs.

The line is normally very clean on the 17070 QLT.

Nothing special about the line, apart from "wandering around the houses" for about 250 Metres, when it could have been about 50 Metres. Basically all underground.

I unplugged that VDSL Splitter, thus totally disconnecting everything internally, POTS and Broadband.

I plugged in a relatively simple, elderly corded phone, immediately hearing the Dialling Tone without any obvious noises, distortion etc.

I dialled 17070 QLT but did not get any response. Tried another twice, again without response, simply "silence".

So I tried 123 Speaking Clock twice - and DID get the expected Time Announcements.

Absolutely clear, no noises, hums, extraneous signals etc.

Restoring the wiring to "Normal", I returned upstairs, where the BB had fully recovered, leading on to this reply.

------------------

The one uncertainty is as to whether not having the Bright Box in the circuit, did the FTTC DSLAM cut the the VDSL signal?

(From forum postings, that seems unlikely, given that the VDSL continues to function with one wire broken.)

I must sort out a simple Phone line Doubler, to repeat the tests, keeping all the normal devices on-line, via the doubler.

With the domestic wiring restored to normal, I tried 17070 QLT again - this time getting the normal responses etc.
Standard User RobertoS
(elder) Sun 11-Dec-16 09:14:04
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Re: VDSL through ADSL v1.0 master socket?


[re: eckiedoo] [link to this post]
 
What are you raving about? What has that got to do with anything I've posted? It most certainly has nothing to do with the OP's questions.

What I did post was that you were talking rubbish about the filter preventing the phone load attenuating the broadband. Though earlier this morning I did spot a minor mistake in my post. I said the phone load between the filter and the MSAN/DSLAM is a given. That's correct, but should have been "between the modem and the MSAN/DSLAM is a given".

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 60000/15199kbps @ 600m. - IPv4

Edited by RobertoS (Sun 11-Dec-16 09:14:24)

Standard User eckiedoo
(fountain of knowledge) Sun 11-Dec-16 13:41:06
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Re: VDSL through ADSL v1.0 master socket?


[re: RobertoS] [link to this post]
 
"
RobertoS
(elder)
Sat 10-Dec-16 19:27:43

I thought it was so the phone was usable. The racket DSL puts on the line would make it impossible to use.
"
(My emphasis - eckiedoo)

Have you, Robertos, or anyone else actually tested that statement AND published the results?

-----------------------------------------

As I could not recollect if I had specifically checked my phone line, to see if it behaved as you described, I tested as described in my earlier post.

As my physical test results clearly contradicted your statement, I felt it would be useful to all, to give you (and others) the opportunity to review my results, try to duplicate or refute them rationally etc.

Hence my presenting them in detail, as is normal for such situations.

--------------

Since then, I found my simple Line Doubler (ie no filter) and have generally repeated the earlier tests.

The results were the same, although the old corded Test Phone was clearly on-line simultaneously with the the VDSL signals.

I also tested the Test Phone by having it as the only item directly connected in to the old non-filtered NTE.

Under all the test conditions, the QLT and Time Clock calls showed absolutely no signs of audible interference from the VDSL.

This accords with the fact that the xDSL signals are all generated at frequencies well above normal human hearing range.

---------

To increase the possibilities of any interference occurring, I had two computers using the VDSL simultaneously -

a) Tower PC via Ethernet cable directly in to the Bright Box 2 router/modem

b) Laptop (visible from the cupboard as I tested), connected by the main 2.4 GHz WiFi.

I had three sites running simultaneously and separately on both -

flightradar24 - at global level, updating about 10,000 aircraft
https://www.flightradar24.com/-6.42,105.66/2

Meteociel displaying North-West Europe weather
http://www.meteociel.fr/observations-meteo/satellite...

Danish Energy Generation
http://energinet.dk/Flash/Forside/UK/index.html

Additionally, I had TeamViewer running from Laptop to Tower, as I don't have those three sites included on the Laptop, so TV was a means of accessing and copying over the URLs.

-----------------

Just after I had connected the old Corded Phone directly to the old NTE, nothing else connected - there was an incoming call, which again behaved exactly as normal and as I would have expected.

-----------------



The old Corded Test phone was fully usable in all of the described circumstances.

No untoward noises etc of any sort, contrary to your statement quoted above.
Standard User TheEulerID
(experienced) Sun 11-Dec-16 15:02:27
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Re: VDSL through ADSL v1.0 master socket?


[re: RobertoS] [link to this post]
 
The filter is there to stop the phone essentially short-circuiting the high frequency DSL signals, not to stop noise on phone. The phone will just present a low-impedance path either all the time, or when it's picked up (depending on the design). Any effect on noise on the phone is simply a side-effect and quite possibly inaudible. The frequencies used by DSL are beyond the audible range.

I suspect that the performance difference between a (well designed) ADSL and VDSL filter will be pretty well zero. They are simply low-pass filters plus a cricuit to re-generate the ring line.
Standard User RobertoS
(elder) Sun 11-Dec-16 15:22:40
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Re: VDSL through ADSL v1.0 master socket?


[re: eckiedoo] [link to this post]
 
Which logically leads to the conclusion that filters are not needed.

Which we know is untrue.

Point 1.
You yourself stated that the broadband side is straight through, i.e. the DSL and phone signals are present all the way from the MSAN/DSLAM to your modem. A filter does not and cannot make a difference to the broadband signal attenuation.

Point two.
If a phone is connected to such a circuit without a splitter two things can happen. You may not hear the signals themselves, but it's worth listening to see if you hear anything at the point you switch your modem(-router) on.
More importantly the signal-carrying wires of the phone and any extension cabling easily pick up electromagnetic noise in their environment. Any ring wire present also being a prime factor in noise pickup.

Filters, as you say, filter the high-frequency signals coming down the line. They also prevent any picked up noise on the filter to phone wiring from getting back onto the line to the MSAN/DSLAM.

Good modern filters also make sure noise picked up by ring wires are prevented from getting onto the line. Cheapos may not.

None of the above affect the signal attenuation!. They affect the Signal to Noise Ratio which generally we don't see, and because they affect that they also affect the Signal to Noise Ratio Margin (post-sync), which is what we do see reported by our modem(-router)s.
The filters are in the PHONE side; and are High-Frequency Reject Filters/circuits, to prevent the ADSL/VDSL signals from being attenuated by the PHONE load
is simply complete rubbish and the sort of thing that leads to internet myths.

As for connecting a phone directly to an NTE with no router on the circuit, and not getting any problems, something you stated twice in that post - ?????? What else would anyone expect?

In an earlier post you said "The line is normally very clean on the 17070 QLT". Short of thunderstorms in the area it should be always very clean. If yours isn't, I suggest you have a problem.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 60000/15199kbps @ 600m. - IPv4
Standard User RobertoS
(elder) Sun 11-Dec-16 15:29:21
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Re: VDSL through ADSL v1.0 master socket?


[re: TheEulerID] [link to this post]
 
The poster seems to have proved to his complete satisfaction that phone and broadband work perfectly with a simple line-splitter, no filter.

The point about the DSL signals being outside hearing range is valid. I shall try sometime to see if anything is audible without a filter when synchronising smile.

I may be wrong on the audible side, but I am most certainly right that they are nothing to do with preventing the phone load attenuating the broadband signal smile. Which was in fact my main reason for posting in the first place. Dangerous misinformation.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 60000/15199kbps @ 600m. - IPv4
Standard User eckiedoo
(fountain of knowledge) Sun 11-Dec-16 17:48:03
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Re: VDSL through ADSL v1.0 master socket?


[re: RobertoS] [link to this post]
 
Point 1
At least we are agreed that the xDSL connections are straight through.

Regarding the filter and possible attenuation from the PHONE side, assume that it is a very poor filter, impedance in the low ohms - would that not place a degree of load on the xDSL side and thus cause some attenuation?

But agreed with the assumed high impedance of such filters across quite a wide band, that attenuation should be minimal.

So theoretically possible; but unlikely in practice.


Point 2 - Modem switch-on.

It would be awkward for me to carry out such a test properly, requiring the co-operation of another person because of the relative locations of the items.

I have tried the following.

With all my POTS and Modem wiring as normal, I did use the 17070 QLT on the adjacent (corded) phone, leaving that running whilst I unplugged, waited about 10 seconds and reconnected power to the modem.

The phone was on its speaker side, at maximum volume.

There were no sounds emitted by the phone over the whole 5 minutes 20 seconds that the operation took, apart from the QLT announcement about every 15 seconds.

The modem was re-powered at about 30 seconds, taking another 3 minutes to establish full contact, followed by my taking the computer on-line for the remaining QLT time (automatic QLT shut-down) and longer.

As I have already stated, that was with the house phone/broadband wiring "as normal" - but it is slightly unusual.

The modem has a direct separate "Ethernet" or similar cable straight down to the NTE area in the cupboard; but originally was connected to the Phone wiring locally via an VDSL filter.

When I obtained that cable, I left all of the xDSL filters scattered around the house in situ, including the local one, just in case I ever had to revert back.

At the NTE in the cupboard, I fitted a new (dangly) VDSL filter directly in to the simple, ancient, unfiltered NTE, with the new direct modem cable in to the straight-through VDSL side, whilst all of the various phone lines were connected in to the PHONE filtered side of it.

Thus all of the phone equipment effectively have two filters in series, the (new) one at the NTE and their own individual ones at the various phone outlets.

It does work, getting typically 37/9 on a 40/10 contract, at about 300 Metres electrically from the FTTC.

The new direct cable to the modem, 10 Metres, brought about a 200 Kbps improvement in Dowload.

------------

Regarding the QLT, I check that in odd moments about once per week; and have never had any problems with such, in xDSL days.

But about 1988 in the good-old dial-up days, 300 Baud and all that, there was a problem with noise on the line - and it was helping the BT Phones lad to track that down, that made me aware of the otherwise invisible peregrinations of the "D-Side". (Crimp joints re-made)

It was also back about then that I had that line attenuation measured, it turning out to be about 23 db over the full length, Exchange to house.

It cost £25.
Standard User TheEulerID
(experienced) Sun 11-Dec-16 18:33:20
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Re: VDSL through ADSL v1.0 master socket?


[re: RobertoS] [link to this post]
 
I think you are incorrect in that belief. It may be that some modern phones have low pass filters built in them, but that wasn't historically the case, and there's a lot of that stuff still around. That's particularly so with "steam age" line-powered phones (which we are all urged to have at one of as they work in power cuts). Line-powered phones tend to present a low impedance across a wide frequency range, which is not a good thing at all for xDSL.

If all the xDSL filters are removed and voice equipment just connected in parallel with the modem, then the symptoms might well include a much lower sync speed or sync being lost when a call is made/received. I have experienced exactly that (with a DECT phone - the ADSL signal would sync until the phone was lifted when a filter wasn't used). Note that splitter is often used as an alternative term for a microfilter (at least according to Kitz). It does not necessarily mean that it's a simple Y connection.

Mostly the low-pass filter is there to protect the xDSL signals. It has a secondary role in preventing xDSL signals getting to the voice equipment (some may be vulnerable, but not those old line-powered phones).
Standard User RobertoS
(elder) Sun 11-Dec-16 18:48:56
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Re: VDSL through ADSL v1.0 master socket?


[re: TheEulerID] [link to this post]
 
Which belief?

It's eckiedoo that said:-
In reply to a post by eckiedoo:
Since then, I found my simple Line Doubler (ie no filter) and have generally repeated the earlier tests.

The results were the same, although the old corded Test Phone was clearly on-line simultaneously with the the VDSL signals.

I also tested the Test Phone by having it as the only item directly connected in to the old non-filtered NTE.
and
In reply to a post by eckiedoo:
The ADSL and the VDSL sides of the devices, whether you call them splitters or filters; are actually "Straight-through".

The filters are in the PHONE side; and are High-Frequency Reject Filters/circuits, to prevent the ADSL/VDSL signals from being attenuated by the PHONE load.
It seems you either agree with him about the latter, or prefer just to argue with me and leave that unchallenged.

The major misinformation is that the filters are there to prevent attenuation. Funny that the fact the phone signal goes straight to the modem without that attenuation.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 60000/15199kbps @ 600m. - IPv4
Standard User 4M2
(knowledge is power) Sun 11-Dec-16 19:16:20
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Re: VDSL through ADSL v1.0 master socket?


[re: RobertoS] [link to this post]
 
An Interesting question regarding this: http://aa.net.uk/broadband-phoneline.html

I guess for fault testing then a filter and phone would be required (if the modem remains sync'd to the exchange) but just for broadband use then a filter would not be required?
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