Speed Calculation

Forums › 2degrees (including Slingshot, Orcon, Flip, Stuff Fibre, MyRepublic, 2talk and Vocus) › Speed Calculation

networkn

Networkn
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#78571 4-Mar-2011 11:15

Hi There!

Out of interest, is there an approximate calculation you can do to estimate speeds over distances for adsl2+?

If I was getting 9 Megabit from the BHB Exchange which was apparently 3.1KM's from my house, if the new cabinet supposedly going in soon, is only 450 Meters from my house, how does that generally work out?

garvani

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#445459 4-Mar-2011 11:19

This chart is fairly accurate

As noted at 450m, you should be maxing out your line speed, all dependant on the wiring inside your house etc though

Ragnor

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#445519 4-Mar-2011 14:45

That chart is for 6dB noise margin, Telecom wholesale uses a more conservative 12dB noise margin.

Basically chop between 800-2400 kbit off each value from that graph.

With a cabinet ~450m from your place you should be able to get a line rate of 17-18Mbit. Note: You may need to improve your house wiring to remove noise/interference and it may also depend on what adsl modem/router you have.

networkn

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#445523 4-Mar-2011 14:56

19450 is what I am getting, they connected me today! Surprise for me.

only getting 620 up though, I was getting 1Mbit up. Something isn't quite right.

Ragnor

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#445525 4-Mar-2011 15:01

What make/model modem do you have?

networkn

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#445531 4-Mar-2011 15:09

Zyxel 2616HW

I switched from the Orcon home hub as it gave me a jump of 1mbit over their dsl sync rate. I would happily buy something else if I thought I could get even better.

Ragnor

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#445598 4-Mar-2011 17:39

Can you post the line stats from in the Zyxel admin ui (line attenuation, snr, noise marging etc)?

Not familiar with that particular model, so don't know what chipset it's using... typically the new line cards Telecom are using work best with models using broadcom based chipsets.

networkn

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#445694 4-Mar-2011 23:27

up down
SNR Margin: 8.2 13.8 db

Line Attenuation: 6.0 5.7 db

Data Rate: 19013 620 kbps

I am really dissapointed, after waiting for this for MONTHS, I have got 19mb connection rate, but I can't seem to break 12-13mbit speeds. I know for a fact I can max out my connection using the same stuff I have always used (usenet) because the servers I connect to are 100+mbit, but I seem to fluctuate HEAVILY between 7mbit and 13mbit.

Also puzzled my upload rate is lower than it was before (1mbit).

Speedtests from Auckland I can't break 8mbit.

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#445727 5-Mar-2011 09:37

Hi, the fact that you cannot get over 8-13Mb/s is something you need to talk with your ISP about, I have 17-18Mb/s sync rate and on Telecom can pull 15-16Mb/s speedtest off most NZ speedtest servers pertty much anytime of the day, school holidays maybe not quite there :)

As for your crimped upload speed, there could be too common issues, firstly the modem, some dont negotiate well with the DSLAM, this is chipset and firmware related, using a Broadcom chipset modem will ensure you dont fall into this. Oddly the behavour of some modems in G.DMT(ADSL1) does not always follow through to ADLS2.

The other big issue is house wiring, a failing filter, or too many filters is a common cause of upload speed issues, once again, to get the most out of you line use a central filter. How many filters are across the line, maybe a brief explain of what sockets and whats connected will help, also try a simple isolation test, ie remove everything from the phone sockets, except the modem. Also is there a house alarm (monitored or not) if its connected to the phoneline it can have issues.

Cyril

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#445911 6-Mar-2011 02:06

I agree the lower upload rate is likely a compatibility issue between the modem and the new gear in the cabinet. Are there any firmware updates for the device, I would check that?

There is no guarantee you will get your line rate in real world throughput, especially in peak time and especially internationally.

A residential internet service is best effort and shared meaning ISP's do not buy bandwidth at 1:1 rates with users line rates, they couldn't afford to do and offer service at current prices.

ISP's generally buy bandwidth at a contention ratio that they can afford, eg: 400:1 which would mean 10Mbit of say international capacity for every 40 users, or 100Mbit for every 400 users etc.

The principle is somewhat similar to a motorway, if you have 400 cars going south at 8am you don't have a 400 lane motorway, you have 4 lanes and traffic queues and flows - effectively you are sharing a expensive shared resource.

Some ISP's run much worse contention ratios than others, some ISP's have attracted a demographic that is all heavy leechers hence more congestion whilst other ISP's have lost of low usage business and granny users.

In my personal experience performance is great on Telecom, Telstraclear, Maxnet, Iconz, Actrix, Inspire. Average on Vodafone, Orcon and Xnet. Poor on Slingshot, Worldnet.

Sounddude

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#446932 9-Mar-2011 12:52

networkn, can you PM me your username?

Cheers.