- I have a lame question
- Posted by Ben Frankcombe on September 16th, 2003
Hi there.
I understand that this is a U.K group but the questions I have may not yeild
differing answers between countries.
This may sound silly but here in Australia all ADSL providers advertise
their speed in Kbps, for example 256Kbps. As far as I understand, this
means kilo-bits per second. Being 8 bits to the kilobyte then 256Kbps would
mean 32 kilobytes per second. Is this true?. No one here seems to want to
answer this question.
Secondly.
I used to know a rather 'savvy' lad by the name of John (MCSE) who
claimed that he tweaked his windows registry to give him greater download
speeds. What are your thoughts on this. If this is possible then how does
one go about doing this.
Thankyou very much for your time.
Cheers;
Ben Frankcombe
frankcombe@(spam is bad)austarnet.com.au
- Posted by Dolphin Boy on September 16th, 2003
"Ben Frankcombe" <frankcombe@austarnet.com.au> wrote in message
news:bk6t0c$ltr$1@austar-news.austar.net.au...
Close enough, my 512Kbps lins gets a max of approx 60KBytes/sec (64Kbytes
if you do the math)
Good for him. I dunno.
- Posted by MarkČ on September 16th, 2003
Dolphin Boy wrote:
<snip>
And to answer the second part, he is probably referring to the MTU
setting on the network interface.
Here'a a nice little link for you, http://www.dslreports.com/faq/5793 ,
tells all you need to know.
HTH
--
MarkČ
Now Playing: Canned Heat - Parchman Farm
- Posted by Tiny Tim on September 16th, 2003
Dolphin Boy wrote:
Have a look here - http://www.dslreports.com/front/drtcp.html for a utility
that allows you to adjust settings. The problem is in knowing what the
settings should be. I guess this is where there will be country specific
variations.
In the UK there was a big thing about setting MTU to 1576 (or something like
that) as the default settings in Windows were inappropriate. But this
setting was specific to the BT network. BT even provided a little executable
to fix/restore this setting.
I remember when using my company's VPN I had to change a registry setting (I
think it was MTU) and this improved my throughput from about 1 byte per
second to the maximium for my ADSL connection.
Disclaimer : I'm not very network savvy so I can't offer any more help or a
better explanation of the above.
- Posted by Harvey Van Sickle on September 16th, 2003
On Tue, 16 Sep 2003 11:45:54 GMT, Ben Frankcombe wrote
AIUI, you've got the maths right.
There's often some loss, of course -- my 600kbps connection, for
example, which should give me a download of 75 kB/s (600/8), usually
comes in at around 70.
--
Cheers, Harvey
- Posted by Jason Clifford on September 16th, 2003
On Tue, 16 Sep 2003, Harvey Van Sickle wrote:
That's not loss - it's protocol overhead.
The 600Kb/s or 512Kb/s figure is the total bandwidth capability of your
connection.
The actual data is encapsulated within IP data packets according to the
protocol in question (TCP for most applications). The protocol has to add
certain information to each packet such as the source and destination
addresses and information necessary to manage the data flow across the
connection.
70KByes/sec is about as much as you can reasonably expect from a 600Kb/s
connection. Likewise 60KBytes or so is what you should expect from a
512Kb/s connection
Jason Clifford
--
UKPOST.COM get your @ukpost.com address now...
http://www.ukpost.com/ professional hosting/ADSL Broadband
- Posted by Jack on September 16th, 2003
That's pretty good. My rule of thumb used to be that over a network,
count on ten bits per octet. That would have resulted in a transfer rate
of 25 KB/s, which is a lot less than the 30 KB/s that seems to be nominal.
But my rule of thumb is old - and not internet-based at all.
--
Jack.
- Posted by Hamish Marson on September 16th, 2003
Ben Frankcombe wrote:
No. Not silly. This sounds perfectly sane.
Serial lines are always (I have yet to experience it when it's not) advertised in bps. (bits per second). Whether it's Mbps or kbps.
It's thanks to the advertising industry & others who think it's cool to mix Bps and bps which are actually different measurements being Bytes per seconds and bits per second respectively (b=bit, B=Byte) and start talking Mb of RAM when they should be talking MB of RAM etc...
OK.. Rant over...
But yes. Serial lines are always measured in bps (bits per second). Plus that's a raw speed. You have to add in framing bits, packets & cell overheads when talking about actual transfer rates. On a 512kbps link you'll get around 55kBps of actual data across the link.
--
I don't suffer from Insanity... | Linux User #16396
I enjoy every minute of it... |
|
http://www.travellingkiwi.com/ |
- Posted by Harvey Van Sickle on September 16th, 2003
On Tue, 16 Sep 2003 14:45:53 GMT, Jason Clifford wrote
-snip re: 600Kb/s service, averaging about 70KB/s-
The reply from Jack also figured 70 KB/s was pretty good. I'm on a
cable modem rather than ADSL, though -- does that have anything to do
with achieving low overheads?
--
Cheers, Harvey
- Posted by Jason Clifford on September 16th, 2003
On Tue, 16 Sep 2003, Harvey Van Sickle wrote:
Not really. Cable in the UK is based upon ethernet rather than serial
protocols however the IP protocol overheads are all that really matter and
they are the same regardless of the physical layer (serial lines or
ethernet).
Jason Clifford
--
UKPOST.COM get your @ukpost.com address now...
http://www.ukpost.com/ professional hosting/ADSL Broadband
