Simple Question on Connection

[Darthshearer]

Hi Guys

When I say simple it will be for you guys and its should be an easy question to answer.

Anyway here goes. I got asked the other day by my mate who has a 600k connetion, if you have a 600k connection why is he DL @ 60 = 90kbs? I told him it was down to couple of factors on, where he was DL from and what other people were downloading from it too. Am I correct?

Also if he connected to me and there was just he and I on a newtwork, with just him DL from my machine and me not doing ANYTHING, what speed would he be thinking of getting?

Thanks guys

 

[RedVenom]

600kb/sec is NOT the same as 600k/sec. Semantics or what.

It'll also be limited by the connection speed at the remote end, contention ratio and all that old jazz.

If your final question is asking about a LAN, then presuming you have fairly decent network switch then the bottleneck will be things like your drive I/O and buffer. You should however still kick out about 6-9Mb/sec. Lots of variables though.

 

[Darthshearer]

If he just connected to me through the internet, (If possible???) what would he get?

If he is A is on 1Mb and B is on 1Mb?

 

[MrBlack]

If he just connected to me through the internet, (If possible???) what would he get?

If he is A is on 1Mb and B is on 1Mb?

Almost certainly the theoretical maximum you'll get if one of those 1Megabit (I'm being specific here) links is 256kilobits/s. Most 1megbit ISPs only allow 256kilobits upstream, so there's you're bottleneck.

Covering the other aspects, there's always a 20%ish overhead from the various network protocols, so that's maybe 220kilobits. ~ 25 kilobytes/s sustained transfer.

I assume the 600k. is the ntl one. With cable modems, there's bit of bandwidth consumed by background traffic, and contention can really rip it out of you (he'll be sharing that line with anything up to 50 other people).

That said, I have the same ntl service, and the major limiting factor in downloads is the server. Some sites I can get 80kilobytes/s, some I get 12.

Oh, and just to confuse the frick out of everyone else. Mega and kilo officially refer to 1000s. When you want to talk about 1024 bytes (2^10), you're supposed to use 'Kibi' and 'Mebi' and even 'Gibi'

... and you thought gibibits were just the left-overs from a heavy Q2-ctf session.

 

[Darthshearer]

Cheers MrBlack

 

[babs]

Am I missing something here (brain still asleep) or isn't this just the very obvious.

600Kbit = 75KByte theoretical max (ie what the downloads are shown as in the majority of programs).

Allowing for overheads, contention etc 60KB/sec (not Kb/sec) sounds reasonable.

Your lan question depends on the cable and NICs, but on a 10Mbit connection you'll probably get just over 1 MegaByte per second.

 

[pgh]

Yup, im on NTLs 600k dl and 256k ul.

If the servers fast enough I will get a straight of 72kb/s.. on average tho it'll be sitting around 60kb/s. As for the connection to your m8s.. if, as you said, it aint a lan and say just doing it FTP itll all come down what your upload is to his download. Eg, if your both 600/256 then max allowed to download is going to be 256kb/s providing your using no other bandwidth on the machine thats serving. Say the serving is again on 600/256 and your m8s was a 56k then he can only get a max of what his conn lets him, being 6kb/s.

 

[Clown]

256 being about 30kb/s yeh?

 

[Deadmanwalking]

The NTL 600k service is 256 up?

Hmm i always thought only the 1 or 2 meg services are 256 up.

 

[Clown]

That's what I thought... then I read this thread. Then I thought I was wrong.

 

[Xavier]

Ok, firstly, don't confuse bandwidth, denoted in kilobits or megabits to your download rates.

To convert megabits to megabytes, divide by eight (eight bits to a byte, after all). That means a 1024kbit line will give 128 kilobytes/sec, not including the overheads and background traffic which go on in parallel to the download itself.

A 10mbit network connection will mean about 1.25 mbyte/sec and 100mbit 12.5mbyte/sec. In the latter you'll nearly never see anything close to this figure unless you have 64-bit pci or do some VERY large dedicated transfers between machines with fast storage.

In terms of upstream, it really depends on your ISP. Any ADSL product based on BT's IPStream product has 256kbit up regardless of package. If you want anything quicker from an IPStream provider you'll have to opt for SDSL, which can cost similar to a full-on leased line in some situations. IPStream isn't the only option for ADSL though, ISPs such as Bulldog DSL sell an alternate product called Datastream whereby they provide all the network infrastructure beyond your local exchange and can offer more upstream, 400kbits being a common figure (and in Bulldogs case a downstream in Central London of up to 8mbit). Datastream also has the added advantage that the ISP can offer 'peak use' packages, where by day you may only have a half meg, and at night 1mbit or 2mbit to play with.

Cable is in comparison a bit of a mess, with more than one cable provider in the UK, and packages varying by region in some cases what you get is simply down to where you live. Common figures are 600kb up / 128kbit down and 1200kbit up / 256kbit down. I'd heard that NTL were considering offering 256kbit up on their 600kbit product but can't find it on their site... Can anyone confirm either way?

 

[Krazeh]

Are the cable packages actually 600kb up or are they including the overhead in that figure?

 

[babs]

Any ADSL product based on BT's IPStream product has 256kbit up regardless of package. If you want anything quicker from an IPStream provider you'll have to opt for SDSL

There is another option now though. Some ISPs such as Andrews & Arnold and Nildram are now offering bonded ADSL which works in much the same way as bonded ISDN lines. Two seperate connections are invisibly (to the consumer) bonded to create one connection, giving you the luxury of higher upload speeds than otherwise available (unless you live near LLU exchange), and only the cost of the channels and £10 a month more. Pretty good value if you ask me.

 

[Panda On Smack]

Edit:

i just said what Xavier said about dividing by 8, spose i should have read the thread first

 

[Athan]

Are the cable packages actually 600kb up or are they including the overhead in that figure?

With NTL it is. Used to be called 512Kbps, then got changed to 600Kbps. Note I say 'called'. I was on it when called 512Kbps and already getting the 600 Kbps speeds for ages before they changed the official labelling. Was getting 70KB/s regularly (average over long downloads) right from the start (Nov 2001).

At least up until ~3 months ago the upload on that was definitely still 128Kbps (still made use of friends' cable at times for various reasons).

-Ath