Central Filter

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Philica

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Topic # 58082 6-Mar-2010 19:29

Hi I live far away from the exchange and i want to try and squeeze as much speed out of my line as possible. Current sync rate, attn etc. This is from a D-Link 502T and yea i do realise this isnt a very good modem.

Modulation     ADSL_G.dmt
Annex Mode     Annex A
Max Tx Power     -38 dBm/Hz

(Down/Up)
SNR Margin
12/25dB

Line Attenuation
49/31dB

Data Rate
1664/160kbps

The house is wired with 4 jack points 3 fitted with splitters to phones and the last to the modem with no splitter. From my understanding if i got a central filter installed this should improve my speed. Also one of the phones seems to effect my data rate. If i plug that in it will drop down to 12xx-14xxkbps. The strange thing about it is its the newest of the phones in out our house at about a year old. So i hope thats enough information and any advice how i can get a faster line without spending to much would be great.

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Reply # 305075 6-Mar-2010 20:56

Hi George, a central filter may help, but not always, what I can say is its the only optimal solution, using multiple inline filters rather than a seperated DSL line from a central filter is the only way of ensuring you do get the optimum result, thats not to say what you currently have is not as near optimal.

What do you get with a basic isolation test (ie everything disconnected except the modem).

Cyril

System

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Reply # 305098 6-Mar-2010 21:48

You must get sick of asking people to do isolation tests cyril, you should just make a tutorial on broadband issues and be done with it

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cyril7

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Reply # 305105 6-Mar-2010 22:09

true, pity they cant read the past threads, its all there

Cyril

Philica

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Reply # 305110 6-Mar-2010 22:31

Sorry i did, it slipped my mind when posting. I have done an isolation test and the line attn and sync rate are practically the same. Also thanks for the help and quick response cyril. This seems you get this alot, or enough for it to get annoying anyway.

cyril7

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Reply # 305175 7-Mar-2010 09:25

No worries George, as system says, I should have done a sticky tutorial long ago.

Regardsless once your attenuation passes the 46dB mark things deteriorate very quickly, and not all that predictably.

Cheers
Cyril

binarybrother

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Geek
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Reply # 305394 8-Mar-2010 12:32

Another good test you can do before deciding to splash out on house wiring and central splitter would be to find the master jack where the outside phone line comes into your house, make yourself up a hook up cable and then connect directly to it with your modem. House wiring can often be a problem. I’d only try that method if you have the proper tools to re-terminate the cables afterwards.

Philica

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Reply # 305421 8-Mar-2010 15:04

Ah so really there's nothing i can do. I don't have the right tools to make myself a hook up cable so i guess ill just have to live with it as is. I could call out a guy but form what you say cyril it could be money down the drain?

Ragnor

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Reply # 305472 8-Mar-2010 17:20

It's hard to tell how much of a difference it would make right now.

Have you checked if your area/address is going to get a cabinet?
http://www.telecomwholesale.co.nz/maps

If you got it done and it didn't make much difference right now it could still be useful for when your address gets cabineted or later in a year or so when VDSL2 becomes available. I believe VDSL2 will require a central splitter.

cyril7

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Reply # 305481 8-Mar-2010 17:45

A central filter is mandatory for VDSL2

Cyril

System

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Reply # 305486 8-Mar-2010 18:03

cyril7: A central filter is mandatory for VDSL2

Cyril

I did not know that, thanks for the info

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insane

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Reply # 305490 8-Mar-2010 18:15

cyril7: A central filter is mandatory for VDSL2

Cyril

Are you 100% sure about that? When one of our staff members trialed the VDSL2 service I'm pretty sure wthey never used a 'central' style splitter. I do remember them saying it was not a standard one as the frequecies are different, and that they were backwards compatible with ADSL2+.

Might be all lies as I was not there to see for myself

cyril7

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Reply # 305491 8-Mar-2010 18:16

It should be mandatory for ADSL2+ in my view, every connection I have dealt with has had significant speed improvements as a result. Bottom line is as the band usage goes up (ie 2+ uses 2.2MHz as opposed to 1.1MHz of ADSL1) then the ill effects of line stubs becomes more apparent, only a central filter can get around this.

Cyril

sbiddle

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Reply # 305494 8-Mar-2010 18:31

insane:
cyril7: A central filter is mandatory for VDSL2

Cyril

Are you 100% sure about that? When one of our staff members trialed the VDSL2 service I'm pretty sure wthey never used a 'central' style splitter. I do remember them saying it was not a standard one as the frequecies are different, and that they were backwards compatible with ADSL2+.

Might be all lies as I was not there to see for myself

It is mandatory. There are no plugin filters for VDSL.

Master splitters should be standard for any ADSL2+ install, the reality is plug in filters were something designed for the days of ADSL and were created so people could do DIY installs. They are not a substitute for a master filter which will in 99% of cases deliver significantly faster broadband speeds if you've got an ADSL2+ service.

cyril7

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Reply # 305505 8-Mar-2010 19:21

The new VDSL2 filter (of which I have many and installed many) are a three port device (Orange=line, Green=modem, Blue=Voice), although from my investigations (hack saw) I can assure the green and orange are the same port, but the new spec from Telepermit required the filter was a three port device regardless of a high pass section being used or not.

My conversations with the guys at Telepermit and my dealings with a larger supplier of home hubs (of which I have designed a whole new series) I can assure you that a central filter is now mandatory for VDSL2.

The current MM3200B ADSL2+ filter is to be phased out, once stocks are gone there will be no more. The newer filter is the same price as the old one, and they are fully backward compatible. From my dissecting of filters it appears that the primary difference compared to the MM3200B is that the first common mode inductor on the input is a much more sophisticated design to allow the filter to be effective through to 30MHz as opposed to the 2-3MHz of the old MM3200B. Naturally the design of the filter that follows the input inductor is also rated out to 30MHz.

Insane, your mate may well have not had a central filter install, as we all know if you have a naked line, which VDSL2 will often be sold with, then you dont need a filter at all, just a clean transmission line without stubs. Also part of the trail was to evaluate if or not a mandatory filter is part of the process.

I suspect you will find that VDSL2 connection will be offered by Telecom with VOIP options, reason being that the modems they have been testing are RGW types with ATA's built in and they have been actively testing this.

Cheers
Cyril

System

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Reply # 305519 8-Mar-2010 20:54

Where can i get one of these new central filters? i might look into getting one and putting it in

PC: 3.3ghz Core i5-2500, 8gb DDR3, ATI Radeon 5850, 27" QHD IPS Monitor

Mobile Phone: iPhone 5 32gb Graphite.

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