Does ADSL sync speed = expected download speed??

Forums › Spark New Zealand (including Skinny and BigPipe) › Does ADSL sync speed = expected download speed??

aschteev

80 posts

Master Geek

#33159 1-May-2009 14:23

Have just recently connected to Telecom's FS/FS Explorer plan at our new place in Avonhead. Unfortunately, our exchange here hasn't been upgraded to ADSL2+ yet.

Anyway, got everything connected up, modem, wireless etc and went to see what sort of download speeds I could get. Was quite dissappointed to only get around ~ 1.5 - 2.0 MBit/sec ie around 200-240 KB/sec download speed. Checked to see what speed the modem was syncing to the exchange at, and indeed it was saying 7616/896.

There is not problem with the speedtest on the upload part of the speed test, i can get around the 800kbps mark, just that the download speed seems to consistently max out around the 200 - 250KB/sec. Surely I should be getting more around the 700 KB/sec mark?

I have played around with filters etc and unplugged eveything except the modem etc etc, and the only change is the slight variation in the sync speeds that the modem connects at.

Since my modem is syncing at these levels, does that mean that there isn't anything wrong with my line, and that I should be getting the higher download speeds? It has been like this for around a month, now. I wasn't sure if it was a one-off thing.

1 | 2

Professional yak shaver
1599 posts

Uber Geek

Trusted

BitSignal

Lifetime subscriber

#211218 1-May-2009 14:31

Not exactly, but you can take an estimate from it.

Chances are you're being throttled.

"Roads? Where we're going, we don't need roads." - Doc Emmet Brown

Talkiet

4793 posts

Uber Geek

Trusted

#211225 1-May-2009 14:43

There are quite a few variables that will affect your speed... Roughly speaking, they are – in order...

Your LAN... If you have a misconfigured LAN, or a wireless network with lots of interference, this can be a problem, but assuming this is ok, the next problem could be at:

Your ADSL router... Some old routers have horrible tiny state tables and slow CPUs. This isn’t THAT common anymore, which leads us to:

Your house wiring... Bad / old house wiring, or missing / broken filters can cause real issues... Next up we have:

The copper between you and the DSLAM. This is variable in terms of quality and distance, and both affect your speed, but your line speed leads me to the next variable:

The DSLAM itself. The numbers you quote (7616/896) are I believe the top speeds possible on ADSL1, this indicates that you have good house wiring, a short length to the DSLAM, but that you have either an ADSL1 capable modem, or are connected to an ADSL1 capable DSLAM only. These are increasingly rare. See this site (http://telecomwholesale.co.nz/maps ) to see if you are in an ADSL2+ area. Assuming you have a good connect to the DSLAM (and it does look like it), the next issue is...

The DSLAM connectivity to the rest of the network. Without going into specifics, each DSLAM services up to 700 odd customers, although up to 300 is more common. All those customers share some amount of bandwidth from the DSLAM to the rest of the network. If you are in a busy area, with lots of students (couhgdownloaderscough) then you’re likely to have variable speeds, especially in the evening. If you’re lucky enough to be on a lightly loaded DSLAM, you will experience less (or no) variability DUE TO THE DSLAM backhaul. However, we’re not done yet... Next we have:

The national aggregation network... Generally this is fine though, and not the cause of any user experience issues in the normal state of affairs. Now we are left with:

Whether you are connecting to a national site, or an international site. International traffic is expensive for ISPs so they have to provision a commercially sensible amount across all their customers – all ISPs will experience slowdowns during peak hours (evenings) to varying degrees. As a general rule of thumb, larger ISPs benefit from economies of scale in terms of users and have less dramatic slowdowns while smaller ISPs can be more variable. This is just in general though... If your site is a national site, then it’s much more likely to be fast. But we’re not done yet... there’s still:

The server at the other end. Is it contended? Are there lots of people using it? It may well be that the speedtest server you are using here offpeak is actually very heavily loaded from people somewhere else in the world.

Given your specific problem description though, I think it’s likely that you are constrained by the remote server, or international bandwidth. I would suggest going to Microsoft.com and downloading something large from there (like a service pack for XP or something) since those files will be cached in New Zealand. That means they will give you the best possible speeds in a real world test.

Try that and report back...
Regards
Neil G

Please note all comments are from my own brain and don't necessarily represent the position or opinions of my employer, previous employers, colleagues, friends or pets.

Talkiet

4793 posts

Uber Geek

Trusted

#211227 1-May-2009 14:48

magu: Not exactly, but you can take an estimate from it.

Chances are you're being throttled.

Actually no... given the description and the plan he's on, that's very very unlikely.

Cheers - N

Please note all comments are from my own brain and don't necessarily represent the position or opinions of my employer, previous employers, colleagues, friends or pets.

magu

Professional yak shaver
1599 posts

Uber Geek

Trusted

BitSignal

Lifetime subscriber

#211228 1-May-2009 14:53

Talkiet:
magu: Not exactly, but you can take an estimate from it.

Chances are you're being throttled.

Actually no... given the description and the plan he's on, that's very very unlikely.

Cheers - N

You can never be too sure. :)

"Roads? Where we're going, we don't need roads." - Doc Emmet Brown

aschteev

80 posts

Master Geek

#211231 1-May-2009 15:02

This is the result from the Service Availability Tool:

This address is scheduled to be connected to a roadside cabinet using faster broadband equipment (ADSL2+ technology) by Apr 2010.

A pre-qualification check is required to determine what broadband services, if any, are available at this address.
Exchange Details

Exchange Area: Avonhead
Projected ADSL2+ Upgrade: Aug 2007
Cabinet Details

Cabinet Name: AVO/J
Projected Cabinet Upgrade: Apr 2010

The address that i'm at is in the green section of the map - but when I used the tool at http://www.telecom.co.nz/broadband/speed/adsl2 it says that "This address is scheduled to be connected to a roadside cabinet with ADSL2+ technology in approximately Apr 2010". So am I not ADSL2+ enabled yet? Even though the Avonhead exchange says it has been upgraded?

I'l have a wee play around with the modem and computer, and see what happens... Thanks for the replies!

Talkiet

4793 posts

Uber Geek

Trusted

#211235 1-May-2009 15:08

aschteev: This is the result from the Service Availability Tool:

[snip]The address that i'm at is in the green section of the map - but when I used the tool at http://www.telecom.co.nz/broadband/speed/adsl2 it says that "This address is scheduled to be connected to a roadside cabinet with ADSL2+ technology in approximately Apr 2010". So am I not ADSL2+ enabled yet? Even though the Avonhead exchange says it has been upgraded?

I'l have a wee play around with the modem and computer, and see what happens... Thanks for the replies!

No probs... It looks like you are in an ADSL2+ coverage area, but the ADSL2+ device is at an exchange... That often means that users can be further away than they would be with a cabinet, reducing their speeds... However your ADSL1 stats indicate you have quite a short copper line so I am suspecting either that your modem is an older mode that doesn't support ADSL2+ (or is specifically configured to use ADSL1 only), or that somehow your line profile is set to ADSL1.

What ADSL router do you use and how old is it? If you can, please include the firmware version... If you look in the GUI for the router, it will probably tell you if it is connected in ADSL1 or 2+ mode.

regards
N

Please note all comments are from my own brain and don't necessarily represent the position or opinions of my employer, previous employers, colleagues, friends or pets.

aschteev

80 posts

Master Geek

#211266 1-May-2009 16:23

The router is a Belkin G Wireless Modem-Router. The model number is F5D7634-4. The firmware that is installed is 1.00.04 (Aug 26 2008 18:04:36). It was only bought a couple of months ago, it says its ADSL 2+ ready, but i can't find ANYWHERE in the GUI or online how to see what ADSL profile it is using. The belkin website doesn't even have this modem on it. Hmm...

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

Talkiet

4793 posts

Uber Geek

Trusted

#211280 1-May-2009 16:52

aschteev: The router is a Belkin G Wireless Modem-Router. The model number is F5D7634-4. The firmware that is installed is 1.00.04 (Aug 26 2008 18:04:36). It was only bought a couple of months ago, it says its ADSL 2+ ready, but i can't find ANYWHERE in the GUI or online how to see what ADSL profile it is using. The belkin website doesn't even have this modem on it. Hmm...

All Telepermitted devices are required to have a phone number for support...

The Belkin number is 0800 235 546 (Found through the Telepermit register on telepermit.co.nz).

Phone them and confirm that it's ADSL2+ compatible - I'm 99% sure it is... But the manual I found didn't have enough screenshots for me to determine where the ADSL type would be shown... If you can find a screen showing your connect speed, and something like "G992.1, G992.1 or G992.5", then take a screenshot and post it here...

At this stage however I'd be tempted to phone your ISP and get them to confirm that you have an ADSL2+ profile enabled. It's not unheard of for the incorrect profile to be loaded against a line. There's also a remote possibility that you're connected to older ADSL1 gear but the Telecom Wholesale site seems to indicate otherwise.

All of this is a little academic though as you're getting a 7.9mbit connect and seeing significantly less than that for throughput... Have you tried the speedtest.net (nz servers) and downloading something from microsoft.com?

Cheers - N

Please note all comments are from my own brain and don't necessarily represent the position or opinions of my employer, previous employers, colleagues, friends or pets.

aschteev

80 posts

Master Geek

#211347 1-May-2009 20:11

Just ran some speedtests: (19:30 - 20:00)

Christchurch Test 1:

Christchurch Test 2:

Wellington Test 1:

Wellington Test 2:

Tauranga Test 1:

Auckland Test 1:

Sydney Test 1:

Sydney Test 2:

LA Test 1:

LA Test 2:

Telecom tells me that I am 1,585m from the exchange, and that my profile is indeed ADSL2+ enabled. Belkin tells me that the modem does indeed support ADSL2+. Current sync rates have changed, now getting approx 6600kbps/945kbps.

Talkiet

4793 posts

Uber Geek

Trusted

#211352 1-May-2009 20:27

aschteev: Just ran some speedtests: (19:30 - 20:00)

Telecom tells me that I am 1,585m from the exchange, and that my profile is indeed ADSL2+ enabled. Belkin tells me that the modem does indeed support ADSL2+. Current sync rates have changed, now getting approx 6600kbps/945kbps.

Right.... some more good info...

The fact you upstream is that high confirms that it is connecting in ADSL2+ mode, but that downstream speed is low compared to what I would expect for just 1.5km from the exchange.

Do you have Sky Digital? Does it have a line filter on it? Try unplugging ALL phones (or anything attached to the phone line) and see if the sync speed improves.

If you have a monitored alarm, you won't be able to remove that - but it may be incorrectly installed.

As for the speeds, they are pretty consistent - but let's see if we can sort out why the ADSL speed is lower than it should be.

Did you have a full splitter install or are you using filters? Are you absolutely sure that there are filters on everything?

Cheers - N

Please note all comments are from my own brain and don't necessarily represent the position or opinions of my employer, previous employers, colleagues, friends or pets.

aschteev

80 posts

Master Geek

#211357 1-May-2009 20:32

Previous owners had SKY digital, but we don't. Can see that the phone jack that was put in for that was connected from another jack in the hallway. Dont have a monitered alarm. As far as I know, we have 3 jacks in this house, one in the kitchen (nothing on it), one in the hall, which has a filter with the modem connected to it, and one by the TV, that was put in for SKY, which has the phone on it through a filter. i have tried a couple of times to disconnect everything and connect the modem straight to a jack, but it doesn't seem to be able to connect to the exchange.

Is it concidence that ALL the speedtests max out at approx the same download speeds?

Talkiet

4793 posts

Uber Geek

Trusted

#211364 1-May-2009 20:42

aschteev: Previous owners had SKY digital, but we don't. Can see that the phone jack that was put in for that was connected from another jack in the hallway. Dont have a monitered alarm. As far as I know, we have 3 jacks in this house, one in the kitchen (nothing on it), one in the hall, which has a filter with the modem connected to it, and one by the TV, that was put in for SKY, which has the phone on it through a filter. i have tried a couple of times to disconnect everything and connect the modem straight to a jack, but it doesn't seem to be able to connect to the exchange.

Is it concidence that ALL the speedtests max out at approx the same download speeds?

No, it's probably not coincidence, but can you please try downloading from microsoft.com and seeing what speed you get there?

Cheers - N

Please note all comments are from my own brain and don't necessarily represent the position or opinions of my employer, previous employers, colleagues, friends or pets.

aschteev

80 posts

Master Geek

#211373 1-May-2009 20:50

Started XP Service pack 3, began at 300KB/sec, is now plateauing at 250-260 KB/sec

EDIT: Apple's Quicktime downloaded at an average of 260 KB/sec

Talkiet

4793 posts

Uber Geek

Trusted

#211383 1-May-2009 20:59

Interesting that it's so consistent... There's one thing you could still try... If you are DLing everything using single threads, then you may have sub-optimum settings on your PC.

If you were to use a download manager like Freedownloadmanager ( http://www.freedownloadmanager.org/download.htm ) or DownThemAll (A firefox extension) that supports downloading with multiple threads, so may find that the limit is your software rather than your line. Give that a crack...

It's just that a consistent 250ish KB/sec is a strange number to be limited at... There were Telecom plans at one stage that limited to 2mbit, but 250KB/sec is above that... Have you ever had an account on that line that had a speed cap?

Cheers - N

Please note all comments are from my own brain and don't necessarily represent the position or opinions of my employer, previous employers, colleagues, friends or pets.

aschteev

80 posts

Master Geek

#211389 1-May-2009 21:21

I wouldnt know of any previous caps on this line, we have only just moved here about 6 weeks ago now. Used uTorrent to try a couple of torrents, see what the combined download speeds were, didn't get above 250KB/sec, kept at a pretty constant 240 - 250KB/sec.

Havn't tried download managers yet, will give that a go soon.

1 | 2