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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.


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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.
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