Download speed in relation to sync speed.

Tr Insanity · 5 Aug 2009 at 09:58

Hey

Was just wondering whether there was a connection between the download speed (when actually downloading something) and sync speed of an internet connection , or is it completely random ?

Thanks , Tr

Paul11 · 5 Aug 2009 at 10:02

its not random

your connection speed ie 8mb will relate to the maximum download speed

edit: there is a formula which i dont remember of the top of my head

Skidilliplop · 5 Aug 2009 at 10:04

It's not random but it's not directly connected. You cannot achieve throughput faster than the sync rate obviously, it will always be slower as there are always overheads.

Throughput depends on the protocols used and their header overheads and contention predominantly.
Your access throughput is usually around 250kbit slower than your synch rate taking into account control signalling and layer2 overheads such as ppp headers and authentication handshaking. However that's only between you and the provider CO, beond that the throughput depends on congestion on trunk links.

In addition on ADSL, providers might implement a profiling system to limit the throughput rate to a set amount for a specific sync rate. E.G on BT I believe a synch rate of ~8,100kbit will get you an IP profile of 7.5Mbit despite the fact the connection could probably get about 7.9 if left to run at wirespeed.

Tr Insanity · 5 Aug 2009 at 10:09

Thanks for the replies

So , hypothetically , if the connection speed was 1mb , what would the average download be estimated at (in real world usage) ?

Skidilliplop · 5 Aug 2009 at 10:10

Tr Insanity said:
Thanks for the replies

So , hypothetically , if the connection speed was 1mb , what would the average download be estimated at ?

It's impossible to say without knowing what affects it.
On an un-contended line with no profiling using PPP at layer2 then you're looking at about 800kbps IP throughput.

Tr Insanity · 5 Aug 2009 at 10:14

Lol , i think it's just me confusing kbps with kB/s.

These are the results i got a second ago from Speedtest.net :

This makes me think that i should be downloading files at 0.98mb/s but i guess that's not how it works

All fine for a 1mb connection ?

Skidilliplop · 5 Aug 2009 at 10:15

Yeah that looks fine. What's the synch rate on that line?

Tr Insanity · 5 Aug 2009 at 10:17

Data Rate Down/Up 1152/288(Kbps)

Annoyed at how slow everything is to download

I get what i pay for though

Caustic · 5 Aug 2009 at 15:13

Thats not a great connection! I hope you are paying too much

Are you not getting confused between 'b' and 'B'? Remember to divide by 8. Also remember that 1Mbps = 1024Kbps.

If you connect at (as in what your modem says) 1152Kbps that means (1152/8)=144KB/s download speed in theory. However, some of that goes on control bits etc, so you normally lose 10%.

So I would expect you to get 1036Kbps or 1.011Mbps top download according to a site like speedtest etc. According to your speedtest image, you got 0.99Mbps, thats about right, and that means roughly a top speed of 123KB/s for download speed and 27KB/s upload.

Does that clear it up?

EDIT: I got my own maths wrong! Corrected.

Tr Insanity · 5 Aug 2009 at 15:42

Tr Insanity said:
Lol , i think it's just me confusing kbps with kB/s.

Caustic said:
Thats not a great connection! I hope you are paying too much

Are you not getting confused between 'b' and 'B'? Remember to divide by 8. Also remember that 1Mbps = 1024Kbps.

If you connect at (as in what your modem says) 1152Kbps that means (1152/8)=144KB/s download speed in theory. However, some of that goes on control bits etc, so you normally lose 10%.

So I would expect you to get 1036Kbps or 1.011Mbps top download according to a site like speedtest etc. According to your speedtest image, you got 0.99Mbps, thats about right, and that means roughly a top speed of 123KB/s for download speed and 27KB/s upload.

Does that clear it up?

EDIT: I got my own maths wrong! Corrected.

Thought I was getting confused , thanks for the clarification

I usually get about 110KB/s download and I never really upload

At the moment I'm paying £12.99 for a fixed 1mb connection with "unlimited" usage , are there any better deals out there ? The one thing i'm worried about is if I change to a "upto" package , will I substain decent speeds ? Unfortunatly we're the last road connected to the exchange so the exchange is 1943m away , via a direct route

Here's what the BT line checker says about our connection :

Your exchange is ADSL enabled, and our initial test on your line indicates that your line should be able to have an ADSL broadband service that provides a fixed line rate up to 2Mbps.

Our test also indicates that your line currently supports a potential ADSL Max broadband line rate of 6Mbps or greater.

Our test also indicates that your line currently supports a potential ADSL2+ broadband line rate of 8Mbps or greater.

I Haven't a clue what most of that means , so if anyone would point me in the right direction please

.

Caustic · 5 Aug 2009 at 16:05

Glad I could help.

The fact that the line checker says you can get 8Mbps on ADSL2+ is good. The question is, can you get the LLU (Local Loop Unbundling, ie no BT involvment). Try the SamKnows website for a good line/distance check. (http://www.samknows.com/broadband/)

If you can get LLU, you can get a miles better deal. Otherwise, it might be tougher.

Tr Insanity · 5 Aug 2009 at 16:10

Caustic said:
Glad I could help.

The fact that the line checker says you can get 8Mbps on ADSL2+ is good. The question is, can you get the LLU (Local Loop Unbundling, ie no BT involvment). Try the SamKnows website for a good line/distance check. (http://www.samknows.com/broadband/)

If you can get LLU, you can get a miles better deal. Otherwise, it might be tougher.

Checked that earlier actually and yes , LLU is available but it's quite limited.

These are the options i have :

C&W / Bulldog:
Enabled as of 15/07/2005
Orange:
Enabled as of 30/05/2008
Sky / Easynet:
Enabled as of 13/06/2007
TalkTalk (CPW):
Enabled as of 01/07/2006

The cheapest O2 deal looked good aswell

Skidilliplop · 5 Aug 2009 at 16:19

Sky would be best bet for LLU out of that list. It'd be worth it to get the 8meg predicted. Chances are the 6meg you're predicted on ADSL will cost as much or more than the LLU which would give you 8.
2km isn't that far. I'm 1600m as the crow flies and get a solid 10mbit on o2 LLU.

Tr Insanity · 5 Aug 2009 at 16:51

Thanks , Sky does look like quite a steal , upto 20mb , True unlimited for £10 a month. I'm gonna look at Sky's phone prices aswell as I'd have to change over from BT. Would it be much hassle to switch everything over ?

Caustic · 5 Aug 2009 at 16:52

Yup, Sky are meant to be quite good, so I would seriously consider that. You should be able to get several times better connection in both directions.

marc2003 · 5 Aug 2009 at 16:55

you have to subscribe to sky tv to get the broadband for £10 month. just thought i'd mention it in case you weren't already aware.

Tr Insanity · 5 Aug 2009 at 17:01

Sky Tv aswell ? 0.o Are you sure ?

It only says this : "Super-Fast Unlimited for just £10 a month - that's £2.50 a week - if it's taken with Sky Talk (otherwise £15 pm)."

Edit : I bet for Sky Talk I'd need to buy Sky Tv or some sneaky thing like that ?

Edit : Bleh , you're right " No. To get Sky Broadband, you need to join, or have joined, Sky TV."

Skidilliplop · 5 Aug 2009 at 17:04

Tr Insanity said:
Sky Tv aswell ? 0.o Are you sure ?

It only says this : "Super-Fast Unlimited for just £10 a month - that's £2.50 a week - if it's taken with Sky Talk (otherwise £15 pm)."

Edit : I bet for Sky Talk I'd need to buy Sky Tv or some sneaky thing like that ?

You don't HAVE to get the phone or TV, you can just get the internet, but they make it much cheaper if you buy a bundle thus securing more money out of you in the long run. It'll still be better value than BT Resale no doubt.

Tr Insanity · 5 Aug 2009 at 17:06

Skidilliplop said:
You don't HAVE to get the phone or TV, you can just get the internet, but they make it much cheaper if you buy a bundle thus securing more money out of you in the long run. It'll still be better value than BT Resale no doubt.

True , it's only £15 but I'd like to keep it at the same price (or cheaper) as i have at the moment

Thanks for your help guys , I shall keep searching

marc2003 · 5 Aug 2009 at 17:16

Skidilliplop said:
You don't HAVE to get the phone or TV, you can just get the internet, but they make it much cheaper if you buy a bundle thus securing more money out of you in the long run. It'll still be better value than BT Resale no doubt.

please research before you post. subscription to sky tv is mandatory to get broadband from them. it might not be an issue if the OP wants sky tv but you cannot signup for broadband without it - hence my post.