Are All Master Filters ADSL2+ Capable

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Yoban

448 posts

Ultimate Geek

#107948 22-Aug-2012 22:24

Hi there,

A slight diversion on a topic covered very well of which I follow closely.

I had a master filter installed by Telecom about 5yrs ago when ADSL2+ was a pipe dream and was wondering if it would have been capable for ADSL2+ or do I need to upgrade it.

It is buried under the house so I cannot get the details on the it and I am approx. 2-3km from MtEden exchange and running draytek2820vn synch'ing at just under 8Mb for download. I have a cat5e line from this to my draytek.

Was trying to squeeze a bit more out of my connection.

Thanks in advance.

Yoban

linw

2850 posts

Uber Geek

#675738 22-Aug-2012 23:35

Well, mine certainly survived through the ADSL 2+ change! Think your limitation is the 2-3 km of copper.

Ragnor

8223 posts

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#675755 23-Aug-2012 00:28

Should be fine, DSL filters are pretty much just analog low pass filters, ie: they filter out the POTS frequencies from the pair/cable going to the modem.

Refer to:
http://upload.wikimedia.org/wikipedia/commons/3/32/VDSL2_frequencies.png

However I guess it depends on the spec's of the particular make/model, could vary.

You can get a brand new Dynamix XDSL telepermitted for ADSL/ADSL2+/VDSL2 for <$30 so you could replace your current one and see what happens for not much $$
http://www.dynamix.co.nz/index.html?do=viewproduct&code=XDSL-MASTER&ID=7829225

gregmcc

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#675767 23-Aug-2012 06:29

Ragnor: Should be fine, DSL filters are pretty much just analog low pass filters, ie: they filter out the POTS frequencies from the pair/cable going to the modem.

Refer to:
http://upload.wikimedia.org/wikipedia/commons/3/32/VDSL2_frequencies.png

However I guess it depends on the spec's of the particular make/model, could vary.

You can get a brand new Dynamix XDSL telepermitted for ADSL/ADSL2+/VDSL2 for <$30 so you could replace your current one and see what happens for not much $$
http://www.dynamix.co.nz/index.html?do=viewproduct&code=XDSL-MASTER&ID=7829225

No they filter out the DSL frequencies from going to your POTS, the DSL modem can ignore POTS frequencies, but you don't want to hear the DSL frequencys overlayed on the POTS when making a phone call, that's why the filter is there.

cyril7

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#675772 23-Aug-2012 07:58

No they filter out the DSL frequencies from going to your POTS, the DSL modem can ignore POTS frequencies, but you don't want to hear the DSL frequencys overlayed on the POTS when making a phone call, that's why the filter is there.

Hi, this is a simplistic understanding, and while filtering the DSL from being heard on the voice side is one of the primary functions it is not "the" prime function.

The prime function is for the filter to lift or create a bridge impedance through the DSL band from the voice port to the input of the filter, this will ensure than whatever impedance is presented on the voice port it will not reflect a disruptive impedance in the DSL band on the input.

As to the OP question, the original DSL filter specification exceeded ADSL1 requirements as even though not deployed here at the time the move to a 2MHz spectrum for DSL2+ was a well understood. So as far as I am aware all Telepermited DSL master filters satisfy the 2MHz spec of ADSL2+. Regardless of that when building a filter to satisfy the DSL1 1MHz band it would infact be quite difficult for it not to continue on to 2Mhz or more, but to expect its characteristics to still be satisfactory at 8 or 12 MHz (or more) as required by VDSL2 is asking a bit much, hence a new spec filter for VDSL2.

Cyril

Ragnor

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#675790 23-Aug-2012 08:48

gregmcc:

No they filter out the DSL frequencies from going to your POT

Doh, I knew that, teach me to post after midnight... should have remembered this diagram:

Yoban

448 posts

Ultimate Geek

#676053 23-Aug-2012 17:27

linw: Well, mine certainly survived through the ADSL 2+ change! Think your limitation is the 2-3 km of copper.

+1

Have had this on the mind as the main cause. Also the kit in the exchange too as neighbour on Orcon is getting 12-14M.

Thanks

Yoban

448 posts

Ultimate Geek

#676056 23-Aug-2012 17:29

You can get a brand new Dynamix XDSL telepermitted for ADSL/ADSL2+/VDSL2 for <$30 so you could replace your current one and see what happens for not much $$
http://www.dynamix.co.nz/index.html?do=viewproduct&code=XDSL-MASTER&ID=7829225

Thanks for that. About to embark on a rewire of data/phone/tv&fm aerials to a central cabinet to be built (as per all great discussions/blogs on geekzone) so an upgrade for that price would remove any fears the issue is with me.

Thanks again.