Broadband speed

[d3ano]

I was reading somewhere that if you change somethingin the registry this will in turn increase the speed of your broadband. Something to do with packet size. Anyone know what i am on about?

Thanks

D3

[TheExcession]

Your broadband speed is fixed by your Service Provider, there is nothing you can do to change that apart from give them more money for a bigger link.

There are however certain tweaks that can be performed to the Operating System TCP/IP software that can in some circumstances improve the throughput of data down certain types of connection.

Specifically this applies to what are called high latency links - that is where it takes a long time for a message to get from one computer to the other.

Usually this is links with a latency approching 500-1000 milliseconds - a prime example being a satellite link.

The problem with high latency links is that the TCP/IP protocol thinks packets are being lost when in fact thay are still 'in the pipe' - you can adjust a parameter called the TCP/IP receive window size, making it larger. This allows TCP/IP protocol to have more data in an unacknowledged state (in flight if you like).

It's all very much swings and roundabouts as having a large receive window means that more data needs to be retransmitted should a packet get lost.

Googling for "TCP/IP Bandwidth Delay Product Receive Window" should give you lots to read if your are interested in this kinda stuff.

I find it quite remarkable to think that a protocol developed in the early 70s is still the fundamental backbone of communication used for the internet today.

best
Ex

bit of stuff here to get you going:

www.dslreports.com/tweaks/RWIN


>> Edited by TheExcession on Tuesday 4th January 11:17

[docevi1]

there used to be a .dll file which would uncap your speed, however this is greatly frowned upon.

[TheExcession]

docevi1 said:

there used to be a .dll file which would uncap your speed, however this is greatly frowned upon.

Do you mean there was some goofy dll that would magically reconfigure the ISP's hardware to up your DSL speed?

That's a new one on me - would've thought the ISPs would've had that hole well covered.

best
Ex

[GregE240]

docevi1 said:

there used to be a .dll file which would uncap your speed, however this is greatly frowned upon.

Rubbish.

[docevi1]

I think it's on Telewest rather than ADSL, and it was a fairly long time ago (when it first came out).

The story went that there was a .dll file installed on your computer which capped your line, by reconfiguring it you could gain extra speed. It was in the days of "install our software to gain access", but the people doing it were always caught within days apparently.

I'm sure it will have changed nowadays mind.

[si_j]

depends if you are on about the MTU setting

see:
http://freespace.virgin.net/adsl.tech for more info.

[arcturus]

si_j said:

depends if you are on about the MTU setting

You are quite right, this can, in some circumstances have quite an effect on the rate at which data is downloaded. Note this is different to the connection speed which is set at whatever you pay for.

By default most routers etc come with the MTU size set at 1500. However, the BT ADSL network works best if you set the MTU to 1458. I was installing Demon broadband at a customer recently and the service was distinctly below average until I changed the MTU in the router to 1458 at which point the data started to flow as it should do.

Similarly if you connect to broadband with AOL, you must set the MTU to 1400 for the service to work properly. (AOL are the odd ones out - everyone else works best at 1458)

[trevorw]

Youll be wanting a program like this then...
www.speedguide.net/downloads.php

I've used it and it did make a slight difference.

[malman]

Except that the 1458 MTU is supposed to be a waste of time these days as BT have reconfigured the ATM network that DSL is tunnel down to allow full 1500 byte TCP/IP.

But hey if it work for you go for it.

[arcturus]

malman said:

Except that the 1458 MTU is supposed to be a waste of time these days as BT have reconfigured the ATM network that DSL is tunnel down to allow full 1500 byte TCP/IP.

All I can say is that 4 weeks ago 1500 didn't work well on a Demon install and 1458 cured the problem.

And you still need 1400 for AOL.

But I fully accept your comment that BT are supposed to have sorted it all out, I had heard this too. Guess they are not telling us the whole truth.

>> Edited by arcturus on Tuesday 4th January 17:52

[thepassenger]

As many have said, for ADSL fiddling with the MTU settings can increase/decrease the throughput, however it won't be a dramatic increase.
It's impossible to 'uncap' an ADSL link because the allocation is controlled by the exchange, which in turn is controlled by your provider.

Cable can theoretically be uncaped, as it's often the cable modem/set-top box which controls the banditdh. It used to be that there would be windows drivers for a modem would control the bandwidth... but these bits of hardware are long gone really.
Of course uncapping your modem is a fairly major violation of your TOS and most ISP's will detect this and boot you off their network, some might well decide to sue you for breach of contract.

The simplest and most hassel free way to get additional bandwidth is to buy it from your ISP.

[agent006]

GregE240 said:

docevi1 said: there used to be a .dll file which would uncap your speed, however this is greatly frowned upon. Rubbish.

True, changing files on your PC will only change how efficiently it uses the connection, not the actual size of the connection. Much like tuning your suspension will make your car go faster round corners but won't give you bigger tyres.

[malman]

agent006 said:

GregE240 said: docevi1 said: there used to be a .dll file which would uncap your speed, however this is greatly frowned upon. Rubbish. True, changing files on your PC will only change how efficiently it uses the connection, not the actual size of the connection. Much like tuning your suspension will make your car go faster round corners but won't give you bigger tyres.

Both docevi1 an passenger are right, on the old cable systems you could reprogram your customer equipment to uncap your bandwidth. It wasn't generally detected originally but they did start to look for it. Those days are long gone and bandwidth allocation is not done in your equipment.

AOL needs a 1400 MTU because they want to be awkward they also use their own dialup adapter for modem users just to be different. IMHO

They'll probably buy Apple

[randtis]

Sorry, this is a bit off the subject

Anyway, after gathering advice regarding broadband, we have now got 1MB with Wanadoo. Everything is great as far as I am concerned, I don't download huge quantities of videos or music, just float about between websites. However, when downloading the 'transfer rate' is around the 120KB/s mark, is this what is to be expected? I vaguely remember reading something which suggested actual speeds are slower than quoted, but I just wanted an experts opinion.

If there is this quoted difference, and it is normal, does it mean 512KB/s broadband is actually about 60KB/s and therefore no faster than dial-up? Or does dial-up suffer the same drop? Or shouldn't there be a difference?

Thanks for any ideas

[TheExcession]

randtis said:

However, when downloading the 'transfer rate' is around the 120KB/s mark, is this what is to be expected?

120KB/s is about right for a 1 Meg connection

best
Ex

[darthdicky]

Exactly - bps is bits per second (as in 512K bps or 1M bps) and KB/s is kilobytes per second. 8 bits in a byte so multiply/divide whatever by 8 to get the real amount.

eg.
512Kbps = 64KB/s
1Mbps = 128KB/s

Obviously you won't get exactly this amount as it never runs at full speed due to various reasons...

[arcturus]

And to completely answer randtis' question, analogue dial-up 56k = 7KB/s although you are more likely to see 3 to 5 KB/s in real life which makes 512k broadband around 10 times faster than analogue dialup.


>> Edited by arcturus on Wednesday 5th January 20:07

[randtis]

Wow, thanks for the info, I guessed I was probably getting my wires crossed somewhere.

Just one more query (please excuse my ignorance). Why not refer to the speed in terms of 'bytes per second' instead of 'bits per second'? Surely most people understand or can relate better to 'Megabytes per second' in contrast to 'Megabits per second'. Is this a sinister marketing trick or just the easiest way to quote numbers? I assume as it refers to all aspects of computer performance the way around it is to look out for whether 'b' are uppercase or lowercase.

Thanks again

[arcturus]

randtis said:

Wow, thanks for the info, I guessed I was probably getting my wires crossed somewhere. Just one more query (please excuse my ignorance). Why not refer to the speed in terms of 'bytes per second' instead of 'bits per second'? Surely most people understand or can relate better to 'Megabytes per second' in contrast to 'Megabits per second'. Is this a sinister marketing trick or just the easiest way to quote numbers? I assume as it refers to all aspects of computer performance the way around it is to look out for whether 'b' are uppercase or lowercase. Thanks again

I think it's a throwback to the early days when data transfer rates over phone lines were so desparately slow (75 baud anyone?) that is was genuinely more sensible to measure the speed in bits per second and it has stuck.

Incidentally baud and bits per second are not neccessarily the same. See here

And yes as a general rule, 'b' is bits and 'B' is bytes