Telecom ADSL performance expectations?

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sm3rt

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Topic # 83387 15-May-2011 20:16

I have just purchased a new DLINK 2730B router, this is working slower than my old DLINK 604T. So my investigations led to line quality.

I found this great tool DMT which will display the noise profile on my line from stats on the router.

With all internal phone wiring disconnected i get this view...

Can anyone tell me if I should be logging a call with Telecom to look connection? Are the gaps to be expected?

Downstream varies between 3 and 4Mbs with the new device and around 5Mbs with the old 604T.

Thanks Quentin.

Here's another view working through my house wiring, I can see it's not optimal....

sbiddle

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Reply # 469407 15-May-2011 20:38

You really need to provide a lot more information about your connection.

Are you on a new ISAM that supports ADSL2+? Are your fed from an exchange or cabinet? How far are you from the cabinet or exchange?

sm3rt

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Reply # 469628 16-May-2011 13:35

Thanks for responding..

Sorry, more info then.

The telecom wholesale site suggests that I am not cabinetised and direct off the plimmerton exchange.

However there's a cabinet at the end of my street PLM/D which isn't on the wholesale site but clearly exists.

So I don't know if I'm on a cabinet. Looking at google maps the road distance between my house and the exchange is 1.8 Km's.

I get an attenuation level download of 38.5 dB.

I guess I'm looking to see if I have enough of a case to log a call with Telecom.

Thanks

Behodar

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Reply # 469650 16-May-2011 14:44

sm3rt: However there's a cabinet at the end of my street PLM/D which isn't on the wholesale site but clearly exists.

How big is it? There are small (<1 m high) cabinets which don't appear on the Wholesale maps, which seem to be only for phone (not broadband).

nickb800

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Reply # 469674 16-May-2011 15:08

Behodar:
sm3rt: However there's a cabinet at the end of my street PLM/D which isn't on the wholesale site but clearly exists.

How big is it? There are small (<1 m high) cabinets which don't appear on the Wholesale maps, which seem to be only for phone (not broadband).

Those small cabinets are usually passive distributors (ie a mess of cables, no cool gear). Technically speaking they are for anything over a phone line - dsl included. But since there are no actives in there, all dsl & pots services come from the exchange.

cbrpilot

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Reply # 470518 18-May-2011 14:08

I'd log a fault if I were you. That bit-loading looks a little unnatural.
However, that said, Telecom doesn't guarantee anything in terms of your sync rate etc - i.e. they may come out and test it and say "within spec", and you're not better off. Worth a try though.

My views are my own, and may not necessarily represent those of my employer.

stevenz

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Reply # 470619 18-May-2011 16:28

According to this calculator;

http://fremnet.net/article/216/adsl-theoretical-speed-calculator

that attenuation would put you at around 2.7Km from the exchange. Even given that it looks like your throughput is a bit average. I'm about 0.5Km from my exchange (I could probably see it if I could get onto the roof) and I get around 10-12Mbps on a good day. My attenuation is around 16 dBm IIRC, but my graph in DMT doesn't have those holes in it.

Try unplugging any other phones on the same line and see if it makes any difference? (EDIT: Oh, you already did, sorry)

sbiddle:
Are you on a new ISAM that supports ADSL2+? Are your fed from an exchange or cabinet? How far are you from the cabinet or exchange?

How would one accurately determine all this?

@KnightNZ

richms

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Reply # 470634 18-May-2011 16:50

Chances are that the gaps are in the AM broadcast band and you have an excessive quantity of crap internal wiring connected.

When you say disconnected, did you go to the demarc and cut all the connections to internal phones or just unplug them from the sockets?

Chances are they can do somthing about it if you tested it with just the ADSL router connected straight to the demarc with the minimum amount of non cat-5 (or even 3) rated cable between it.

Remember that most old houses have internal cable that has no business carrying non audio frequencies, and the street cables are not a great deal better.

Richard rich.ms

sm3rt

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Wannabe Geek

Reply # 470736 18-May-2011 20:00

Thanks all for the reply's.

By testing at the demark I did cut all other extensions in the house physically off, but I was still on the end of about six metre's of white bell wire which connects to the black wire under the house.

Funny that AM is mentioned. Over the hill not line of site are the big Titahi bay radio masts, one assumes they pump out a lot of something.

I've paid a lot of wiring maintenance over the years so I'll call in the Tech and see what happens. I thought the graph in DMT was a really useful way to get an idea around what was right or wrong. I can imagine there are a lot of people with dogey internal wiring.

quickymart

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Reply # 470832 18-May-2011 22:26

The transmitter towers in Titahi Bay broadcast the local AM stations around Wellington - National Radio (567AM), Newstalk ZB (1035AM) and 2YB (1161AM).