ADSL filters - is there a difference?

Discussion in 'Networking, Telephony & Internet' started by Akh-Horus, Jul 23, 2010.

  1. mike-s

    mike-s Member

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    Interesting, no other changes to my connection other than ditching the crappy dlink line filter for the phone and the speed in both directions has shot up significantly.

    Code:
    Statistics		Downstream	Upstream
    Line Rate		5675 Kbps	933 Kbps
    Attainable Line Rate	12168 Kbps	952 Kbps
    Noise Margin		16.4 dB		6.3 dB
    Line Attenuation	38.0 dB		19.8 dB
    Output Power		18.6 dBm	12.6 dBm
    Oh and as to ADSL settings, im with iinet and keeping it on "standard adsl2" as i had problems with the more adventurous settings on my old nb5 (since binned) and it saves me the hassle of worrying about if it'll drop, etc. Still happy with the change though.
     
    Last edited: Jul 29, 2010
  2. Doc-of-FC

    Doc-of-FC Member

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    with 16 DB noise margin you should give adsl2+ a go, considering this is a new modem, not the nb5
     
  3. Merudo

    Merudo Member

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    man i just got my connection set up at home and i had to dig out my old nb5plus4W and i have no end of issues. I understand ADSL1 modulation is different but trying a mates old adsl1 modem meant rock solid stability... the NB5 is just a heap of crap. though it has been through hell and back I suppose.

    Cant wait to try a new DSL2 modem to see if it solves my dropout issues... the fact that the modem's interface locks up at times leads me to believe that it's the issue... sync speed certainly isnt, has no probs syncing at 17mbps (its just having a stable connection thats the problem, haha)
     
  4. Dezza Bot

    Dezza Bot Member

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    Probably needs a few new capacitors and a heatsink on the cpu, especially if it's one of the early revisions.
     
  5. mike-s

    mike-s Member

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    Random locking up, are you finding that the ipforwarding is no longer working correctly either? (like if you forward external ports to a specific internal ip/port, etc) If so, time to bin it as you've described half the symptoms i got when i decided to turf my nb5.

    As to going to 2+, might give that a whirl after i finish my ebay-a-thon session this arvo.
     
  6. Merudo

    Merudo Member

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    i will keep it as a "in case of ultra uber emergency" but I just picked up a brand spankin new Billion BiPAC 7800N (the wireless N and gigabit model one with the new broadcom chipset) so I'm hoping that I'm about to cruise my way into line sync nirvana :leet:
     
  7. OP
    OP
    Akh-Horus

    Akh-Horus Member

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    These vary:

    heres today:
    [​IMG]

    Heres a few weeks ago:
    [​IMG]
     
    Last edited: Jul 29, 2010
  8. mike-s

    mike-s Member

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    If its wigging out i would rather go on ebay and buy someones old adsl1 modem for $20 and turf that one to the bin, sorry, no idea of just how badly its stuffing up as i said, when mine went, it went properly.

    As to my gear, changing from "Controlled" to "Standard" seems to have done the trick.
    Code:
    Statistics  		Downstream  	Upstream
    Line Rate 		7717 Kbps 	1023 Kbps
    Attainable Line Rate 	8484 Kbps 	1107 Kbps
    Noise Margin 		10.1 dB 	12.9 dB
    Line Attenuation 	38.0 dB 	19.8 dB
    Output Power 		18.7 dBm 	12.6 dBm
    :)

    Ta for the help & sorry for threadjacking slightly :sick:
     
  9. OP
    OP
    Akh-Horus

    Akh-Horus Member

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    Lol after all the hijacks Ive done I cant complain.

    Getting back to my topic, the filters I have - would I see any difference in switching them with the old ones as previously detailed?

    It seems my line is up and down with bandwidth speed anyway given the two different test results!
     
  10. mike-s

    mike-s Member

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    Dumb question, does the poorer line speeds correlate in any way at all with the weather? i.e. when its been gloomy/rainy within the last week or so the speeds drop, or it speeds up in summer, etc?

    If so, possibly could be related to moisture affecting a join somewhere along the line on your line to the exchange

    Meanwhile, replace the modem, unplug any phones, let us know how you go..
     
  11. OP
    OP
    Akh-Horus

    Akh-Horus Member

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    Its a brand new modem!!!! lol

    Same with phones connected or not.
     
  12. mike-s

    mike-s Member

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    Sorry, i didn't realise that the new hardware was already plugged in, i was talking about the p.o.s. nb5 still.
     
  13. OP
    OP
    Akh-Horus

    Akh-Horus Member

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    Lol nah it is a telstra supplied thompson wireless router I am using.
     
  14. MoonSha

    MoonSha Member

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    If you knew how ADSL and the filters worked, you would realise that there is zero difference between the filtering requirements of ADSL of any kind
     
  15. mike-s

    mike-s Member

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    All an adsl(*) filter does is a "filter" out the frequencies above those used by phone lines for voice calls by acting as a "Bandpass filter" and cutting out all frequencies not related to voice comms on the phone line.
     
  16. Ninjab

    Ninjab New Member

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    Intersting
     
  17. imf

    imf Member

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    I'm sorry MoonSha:upset:, if you do have more knowledge in networking/telecom equipments, which I highly doubt :confused:,

    standard ADSL equipments transmit upto 1.1Mhz Band
    and ADSL2+ equipments transmit upto 2.2Mhz Band

    a TRUE ADSL2+ filter is compatible to the S041:2005 spec which allow upto 2.2Mhz Band
    but most filter labeled ADSL2+ doesn't meet S041:2005 standard and only meet RCIT.0004 standard but the company still label ADSL2+ compatible

    I will lecture you on more difference between a ADSL and ADSL2+ filter below..

    =============
    Here is a summary of the main differences between the Telstra standard for standard ADSL filters, RCIT.0004, and the ADSL2+ standard, AS/ACIFS041 (2005).

    I've seen a few people saying that you can just use an ADSL filter for an ADSL2+ modem. S041 specifies testing to 2.2MHz, compared with 1.1MHz for Telstra RCIT.0004, which is just the first of several significant differences, which include the following:

    -----------------
    Item 1
    Characteristic: Overall Bandwidth:
    RCIT.0004: Only Tested and Certified to 1.1MHz. Half the bandwidth of ADSL2+.
    S041:2005: Full ADSL2+ Band 2.2MHz Certified.

    Item 2
    Characteristic: Unbalance about Earth:
    RCIT.0004: Relaxed requirement of 30dB cuts in at 1.1MHz.
    S041:2005: Clause 5.2.4.8. Relaxed requirement of 30dB cuts in at 2.2MHz.

    Item 3
    Characteristic: Telephone Idle ADSL Band Isolation:
    RCIT.0004: Not Required for Certification.
    S041:2005: Clause 5.2.4.15. Full Compliance to ETSI Off-Line Isolation but extended to 2.2MHz.

    Item 4
    Characteristic: Telephone Noise with filter connected to live ADSL Signals:
    RCIT.0004: Not Tested. Many RCIT.0004 approved filters generate objectionable telephone ‘static’ when live ADSL and ADSL2+ signals are present.
    S041:2005: Clause 5.2.4.17.d. Psophometric Noise Test with live ADSL Signals (better than -62dBmp).

    Learn well my young padawan :thumbup:
     
  18. OP
    OP
    Akh-Horus

    Akh-Horus Member

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    So the filters being sold by Warcom (OCAU sponsor) should make some appreciable difference?
     
  19. Devils

    Devils (Taking a Break)

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    An ADSL filter isolates the PHONE via a low bandpass L-C (inductor-capacitor) passive filter set at about 4kHz. Low bandpass filters were invented 100 years ago.

    The ADSL modem does whatever filtering it needs inside the modem itself. THE MODEM IS CONNECTED DIRECTLY TO THE PHONE LINE. The modem has an internal high bandpass filter that filters out DC (direct current) and anything below around 20kHz.

    [​IMG]
    Yeah sure.
     
    Last edited: Aug 5, 2010
  20. radeon_freak

    radeon_freak Member

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    I'm with devils on this one.

    Also what did you lecture him on? How to use the cut and paste features?

    http://forums.whirlpool.net.au/forum-replies-archive.cfm/590510.html

    Next time a link to the original article/thread would be nice :thumbup:
     
    Last edited: Aug 6, 2010

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