What download speed should i expect?

[dodger]

Originally Posted by bopdude

Nice little app there Paul not that I need it at the mo, getting d/l speed of 171.7 kB/s on one file I can't wait for the upgrade

On the 1.5 service BTW

Me again, Ran Dan,s Broadband Speed Test (Downloaded @ 35kb/s) ("Doh") and the result on test 5: (Download speeds from UK servers) was a bit grim. Ideally it said,should be 768kb/s. I got 282 kb/s and it said "This result shows serious problems with downloads, and should be investigated." Should i call Inter(NTL)national Rescue." or should i just sit it out and wait for the upgrade to 2mb/s? All the other test passed ok.

Originally Posted by dodger

Me again, Ran Dan,s Broadband Speed Test (Downloaded @ 35kb/s) ("Doh") and the result on test 5: (Download speeds from UK servers) was a bit grim. Ideally it said,should be 768kb/s. I got 282 kb/s and it said "This result shows serious problems with downloads, and should be investigated." Should i call Inter(NTL)national Rescue." or should i just sit it out and wait for the upgrade to 2mb/s? All the other test passed ok.

if all the other tests were ok I would say that was a 'one off' - mine are ok

[ian@huth]

It sounds like you are on the 300k service not the 768k that you thought. The speed test only mentions 768 kb/s because you told it that you are on that speed. Give NTL a call to check what they have you down as. You could check the config file for your modem.Have a look at http://www.cableforum.co.uk/board/article.php?a=18 to see how to check your provisioned speed or Robin Walkers site to find out how to check for the config file.

[dodger]

Ian you are amazing!! Tried your link to NTL and found that they have me down as 300kb/s. (Gunna call them later today) Maybe it was the offer that they had on @ the time! "Half price for three months". Maybe what they really mean is "Half line" for three months. Anyway i will post how i get on with "Customer Services" You are so clever. Thanks all. . Keep taking the pills! and smoking the stuff!

[paulyoung666]

Originally Posted by dodger

Ian you are amazing!! Tried your link to NTL and found that they have me down as 300kb/s. (Gunna call them later today) Maybe it was the offer that they had on @ the time! "Half price for three months". Maybe what they really mean is "Half line" for three months. Anyway i will post how i get on with "Customer Services" You are so clever. Thanks all. . Keep taking the pills! and smoking the stuff!

oiiiiiiiiiiiii i thought of it first

[Albie]

I ran that speed test and got these results.

http://img153.exs.cx:81/img153/5586/s13ny.jpg

The RWIN is set at 15000. Is this too high?

[Matth]

Using the DSL Reports formula, http://www.dslreports.com/faq/578
of ping (in mS, but should be a LARGE packet ping, this may be a small packet) multiplied by line speed (in Kbit/s - the K cancels the m) x 1.5 (fudge factor) divided by 8 (bits in a byte).

169 x 768 x 1.5 / 8 = 24336

Your RWIN is actually too small to achieve full speed on a path with a delay exceeding 100mS

[dodger]

Happy again! Turned out that NTL had me on a 300kb/s connection.("Doh")

This was easly changed to 768kb/s by loggin on to the NTL Homeworld website and upgrading. "Took seconds to do!" Noticed the differance straight away.
i can,t wait for the speed upgrade. Anyone know how this will happen? "Will we all just wake up one morning and find our web browsing running @ warp factor?"
or will we be notified by a van driving around with a loud speaker bolted to the roof?

Thank you all again for your advise and pointing me in the right direction.(Cool)
__________________

Oh @and thanks Paul for thinking of it first!
__________________

Matth. "Havn,t got a clue" "what you where on about". But thanks the same.

[mmm]

Originally Posted by dodger

Happy again! Turned out that NTL had me on a 300kb/s connection.("Doh")

This was easly changed to 768kb/s by loggin on to the NTL Homeworld website and upgrading. "Took seconds to do!" Noticed the differance straight away.
i can,t wait for the speed upgrade. Anyone know how this will happen? "Will we all just wake up one morning and find our web browsing running @ warp factor?"
or will we be notified by a van driving around with a loud speaker bolted to the roof?

Thank you all again for your advise and pointing me in the right direction.(Cool)
__________________

Oh @and thanks Paul for thinking of it first!
__________________

Matth. "Havn,t got a clue" "what you where on about". But thanks the same.

The upgrade is supposed to be virtually instantaneous, but you may have to reboot the modem (power cycle, leave off for 30 seconds) before it takes effect.
__________________

Originally Posted by Paul M

Not quite 260 - 2048/8 = 256, then take of a bit for overhead - you should expect around 250 Kbytes/sec.
__________________

I'm looking forward to my 3M - at around 365K/sec.

I suspect NTLs 2 megabit will be 2,000,000 bit/s (The 300k is definitely 300000 bit/s at the moment as defined by the cable modem config).

One byte is about 8.5 bits, 1kByte/s = 1024 bit/s

So I reckon ntl 2MB will be 230kBytes per second if you can find a server that will download fast enough!

[Ignition]

Originally Posted by mmm

I suspect NTLs 2 megabit will be 2,000,000 bit/s (The 300k is definitely 300000 bit/s at the moment as defined by the cable modem config).

One byte is about 8.5 bits, 1kByte/s = 1024 bit/s

So I reckon ntl 2MB will be 230kBytes per second if you can find a server that will download fast enough!

1,024,000 bit/s, 2,048,000 bit/s and 3,072,000 bit/s are the new caps.

This should deliver 120-125kB/s per Mbit.

One byte is 8 bits, no more no less, and 1Mbit is 1,000,000 bits. The extra is a historical thing put in there to account for TCP/IP overheads a bit.

Chances are it won't require a modem reboot, modems will be made to resynch and acquire the new speeds.

[mmm]

Originally Posted by Ignition

1,024,000 bit/s, 2,048,000 bit/s and 3,072,000 bit/s are the new caps.

This should deliver 120-125kB/s per Mbit.

One byte is 8 bits, no more no less, and 1Mbit is 1,000,000 bits. The extra is a historical thing put in there to account for TCP/IP overheads a bit.

Chances are it won't require a modem reboot, modems will be made to resynch and acquire the new speeds.

Hard disk manufacturers and comms companies usually use whatever definition of k and M that gives them the bigger number, but when you format your harddisk the available space is much smaller!

Memory manufacturers usually use the more 'computer science' correct

1 byte = 8 bits
1 kbyte = 1024 bits (= 2^10)
1 Mbyte = 1024 kbyte = 1,048,576 bytes (2^20)

so

I'm sure you know better than me what the ntl config file will say - I'm looking forward to finding out what definition of 1Mbit NTL use (but I still expect a million bits which is consistent with 10/100 Mbit Ethernet definition I believe). And yes my 8.5 bits per byte is an approximation to allow for packet overhead and other losses, for a precise value see

http://homepage.ntlworld.com/robin.d...html#kilobytes

[ian@huth]

Originally Posted by mmm

Hard disk manufacturers and comms companies usually use whatever definition of k and M that gives them the bigger number, but when you format your harddisk the available space is much smaller!

Memory manufacturers usually use the more 'computer science' correct

1 byte = 8 bits
1 kbyte = 1024 bits (= 2^10)
1 Mbyte = 1024 kbyte = 1,048,576 bytes (2^20)

so

I'm sure you know better than me what the ntl config file will say - I'm looking forward to finding out what definition of 1Mbit NTL use (but I still expect a million bits which is consistent with 10/100 Mbit Ethernet definition I believe). And yes my 8.5 bits per byte is an approximation to allow for packet overhead and other losses, for a precise value see

http://homepage.ntlworld.com/robin.d...html#kilobytes

Strictly speaking a byte can consist of any number of bits depending on the architecture of the system on which it is used. 9 bit bytes were fairly common many years ago on 36 bit computers but the number of bits per byte could be as low as 6 or as high as 64 in my experience. A true definition of byte would be the smallest addressable unit of storage.

These days it is commonly accepted that a byte consists of 8 bits. It is impossible to have a byte size that isn't a whole number.

The prefixes kilo, mega and giga mean different things depending on their usage. In communication speeds kilo means 1,000 whereas in file sizes kilo means 2 to the power 10 or 1,024.

Originally Posted by mmm

I'm sure you know better than me what the ntl config file will say - I'm looking forward to finding out what definition of 1Mbit NTL use (but I still expect a million bits which is consistent with 10/100 Mbit Ethernet definition I believe). And yes my 8.5 bits per byte is an approximation to allow for packet overhead and other losses, for a precise value see

I know what definition they use, it's 1024000. I used to be on the 1M service, this is what was used. Multiply it by 1.5 and you get the 1536000 that is currently in use. The new tiers will use 1024000, 2048000 and 3072000 (the uploads will be 100000, 200000 & 300000).

FYI: I use 8.25 as my figure for bits/sec to Bytes/sec (and then /1024 for K bytes/sec).

[Carth]

hmmm .. my speed reports are mostly the same as Albies (705 on download) .. but sometimes with massive ping times/time-outs on "foriegn" urls, and often packet loss between 2 and 10 % ?? Also about 30% of the times I run the test it can't do the download test because of server timeouts or other errors ?

Got my RWIN set at 18000 currently, tried ranges from 15000 up to 65500 with no noticable difference.

Not bothered reporting the packet loss since last time (ages ago) as I can still play online games without "obvious" hitches .. and waiting 30 extra seconds for some pages to load has become normal for me lol.

[Ignition]

Originally Posted by mmm

Hard disk manufacturers and comms companies usually use whatever definition of k and M that gives them the bigger number, but when you format your harddisk the available space is much smaller!

Well no, comms companies use the IETC / IEEE definitions of bits which dictate that baseband comms bitrates are expressed decimally, not binary. Check the specifications for 10baseT, fast and gigabit ethernet for more on this, along with specifications for SDH, POS and the defined bitrates for STM and OC circuits (IE an E1 circuit is 2048000 bps, 2.048Mbps).

If we're getting *really* pedantic kilobytes, megabytes, gigabytes indicate decimal quantities, not their binary equivalents kibibytes, mibibytes and gibibytes. Sorry if I've upset any programmers with that one but that's the way it is, officially apparently - see IETC:

kibi- (Ki-)
a binary prefix meaning 210 = 1024. This prefix, adopted by the International Electrotechnical Commission in 1998, was supposed to replace kilo- for binary applications in computer science. Thus 1024 bytes of storage is officially a kibibyte, not a kilobyte. However, computer professionals generally dislike this unit (they say it sounds like a cat food) so the ambiguity in the size of a kilobyte persists. The prefix is a contraction of "kilobinary." The symbol Ki-, rather than ki-, was chosen for uniformity with the other binary prefixes (Mi-, Gi-, etc.).

It's not really possible to give an exact figure for overheads as they vary depending on the protocol being used for transfer, MRU, if PPP is involved at any point, multiple sources for the same download. Only thing you can say is that with a packet size x the overhead will be y%.

I was just giving the pure unfettered bitrates, the performance I would recommend users to expect from their new services is as I posted, 120KiB/s for each 1Mbit of download speed, 12KiB/s for each 100k of upload speed. Anything else is a bonus!

The joys of comparing transmission/communication rates with storage rates, telecomms vs IT at its' finest.