56K Max DL Speed

Dotsie~tmp

Just a question about the 56Ks maximum download speed. Im on a UTV 56k account and usually get a max of 5.3KBs however tonight when downloading an image from nasa's site i got a constant 12 to 18 KBs?? How is this, it lasted the whole download and just to make sure i checked it with the monitor program and modem status icon (which showed the total downloaded increasing by more than 10KBs). See image. I have never been able to get this speed before and am able to get it every time i download the image. Surely this is around double the maximum theoretical 56K limit.



link to image.

sceptre

Probably an uncompressed tiff. You're still downloading at a sub 56-kps rate, it's just that compression means you're getting the data quicker. That's a really bad explanation so someone else will probably put it better. Try it with a big bitmap and you may well see the same thing. mp3s and jpegs are compressed already so you won't see any gain with these fiels.

Dotsie~tmp

So you say the file is compressed and decompressed BEFORE the monitor programs and modem status read the download speed? What is the program that performs this decompression? Ive downloaded thousands of files many tiffs and have never seen or heard of this. Just to be sure i timed the download again independantly of IE and checked its downloaded file size. I got the same answer as the below one.

Kenshin

I agree, it's due to compression. Most webservers or else proxies use compression to send webpages faster to the browser. This applies to any type of file downloaded from webservers, etc. I believe mod_gzip is the standard compression used, which is transparently supported by both webservers and browsers.

Dotsie~tmp

I think i understand...the file i recieved was actually about 1MB in size and the server automatically compressed and my end decompressed. The reading was a virtaul one? Tell me do all servers support this compression as i have aften downloaded large uncompressed files like bitmaps and have not seen this compression in effect.

longword

Originally posted by Kenshin
I agree, it's due to compression. Most webservers or else proxies use compression to send webpages faster to the browser. This applies to any type of file downloaded from webservers, etc. I believe mod_gzip is the standard compression used, which is transparently supported by both webservers and browsers.

Lets not forget the compression in the modem itself. On a good day, with the wind behind it (and that covers an uncompressed .tiff file quite nicely), v.42bis will do 4:1 compression between you and your ISP's modem.

eirebhoy

How the hell did you get a connection over 50kbs, the most I have ever got was 48kbs with eircom and now I'm with ntl and I get a high of 44kbs. How is it different?

air

Look this crap has been discussed in detail here before, do a search if you're that interested.
Anyway 56k modems are always going to be ****, & you're never going to discover that your modem seems to have "magically" achieved an unprecedented speed.
The restriction is the filter on the exchange side which limits the bandwidth to ~4khz. Theres only so much you can squeeze through that little bandwidth & believe me they're doing very, very well already.

Frank Grimes

Originally posted by eireboy
How the hell did you get a connection over 50kbs, the most I have ever got was 48kbs with eircom and now I'm with ntl and I get a high of 44kbs. How is it different?

It's just down to the quality of the line/modem etc.
I get a 50,666-52,000 connection all the time, and the download speeds match the connection speed.