Thread: dial up users

me a bit sceptical!

19.5kb per sec?

maybe for a milisecond on connection,,,


ok,, will do test.

:?

nothing new here,,,,,

19.5 would be nice,,,


5.5 would be nice,,,
4-5 is nearly normal.

:? now its working again, so will do this while i can!am confused that inc. said toset modem at 56000, but that site(bigpuddle) said to set it at 115000, so did that and now runs slightly better, as for the rest of it i couldn't be bothered getting on and off the net to diagnostic this thing, so.......is good for now!!! 8)

Originally posted by fernockulated
:? now its working again, so will do this while i can!am confused that inc. said toset modem at 56000, but that site(bigpuddle) said to set it at 115000, so did that and now runs slightly better, as for the rest of it i couldn't be bothered getting on and off the net to diagnostic this thing, so.......is good for now!!! 8)

inc said set maximum speed/port speed it to 57600.

warning long winded but hopefully insightful info follows....

for a start lets get a little fact into my argument.

i have been using modems since the days when you had to build your own so i have a better understanding of them than most people.

i live in a semi rural area with a history of utterly abysmal phone lines.

telstra once tried to prove me wrong on this particular point.

they didnt

and i have a 50 pair cable at my front garden that goes nowhere or did last time i looked.

their tech staff still can not understand the difference between a baud rate and a bit rate, which is what this is really all about.

why did inc said set maximum speed/port speed it to 57600bps.

most of the following relates to PC based computers not MAC's or Atari's or Suns etc, they are not interrupt driven.

it is setting the speed your computer talks to your modem at, NOT the speed your modem talks to the other modem at, although under certain conditions it can increase connection speed, but usually thruput over that connection over a period of time will be lessened.

if you live more than 1 klm OR closer than 50 metres from your telephone exchange you will suffer degraded service speeds due to line voltage drops and or shadowing, no if, no buts, it is physics, and can not be overcome without something to influence line voltage characteristics.

if you have a PCI internal modem or a USB modem or PCMCIA modem then 99% of the people running it will actually be running a software modem emulator which bends the following rules a little bit depending on the programming of the emulator.

if you have a normal external modem it uses a serial port to talk to your computer.

most modem computers use a serial port using a 16550 UART with has a 16 byte FIFO buffer (FIFO = first in first out) !

that little FIFO is what give you the ability to use your computer while it talks to another device over the phone line.

While the computer services the other tasks it is doing it stores up to 14 bits of info reliably in the little buffer, it then writes this data to the program using the com port, in this case the connection to the net, and you cannot access the hard drive for reads or writes while it does it....

penny starting to drop?

115,200 bits per second ..... hmmm how many times has your computer got to fill and empty that little buffer of 14 to acheive 115,200 of the suckers in a second.

under windows even in windows xp it has real problems doing it reliably.

linux, os/2 and most other operating systems have serial drivers which can cope at that speed much better but not perfectly.

57,600 is the next speed down available to you.

that takes half the load of the serial port fifo.

BUT

is still fast enough to service the data coming and going in that buffer of 14 in the FIFO at the connect speeds (baud rate) that the average user gets unless you have a very slow hard drive.

test it out yourself.

set your port speed to each setting and try downloading a large amount, say 30 odd mp3's from your favorite site at each setting.

speed isnt everything .... reliabilty is when it comes to internet and serial comms.

you are losing about 15% of your thruput in protocol control and tcpip packet control.

if you have your port speed at 115,200 you WILL be losing packets of info, and your modem and software will need to download some data at least twice and sometimes more to keep control of the data flow.

add a noisy or less than perfect phone line into the equation and the overhead can quickly double or treble, so your internet slows down.

do yourself a favour ignore the 115,200 port speed setting, move it down to 57600 and your internet WILL become quicker because the data thruput will be higher because lost info will be less.

if you have a mac, you will also see improvements if you drop your port speed or turn off v.90 altogether but for other reasons.

:? :? :? :? :? :? :? lost me after "warning could be long winded"
dont get me wrong , not picking on you inc just totally confused!
now even more so, so is back at 57600,whatever!!!!as long as this damm confuser works i dont really give a ****!!!! :? 8O

Originally posted by Pedro_The_Swift
nothing new here,,,,,

19.5 would be nice,,,


5.5 would be nice,,,
4-5 is nearly normal.

and is excelllent thruput on a cheapish 56k modem.

do not confuse thruput with connection speed.

most people connect at about 4200bps or below

theoretical maximum thruput is 5.2k

you lose about 15% in control overhead, ppp and tcpip

you get some of this back using the built in compression in the modem. usually the better the modem, the better the compression the better the speed.

anything above 4k is a good download speed.

use a $600 USRobotics courier modem on the same connection and it will compress that well that you will get 5k+

Originally posted by fernockulated
:? :? :? :? :? :? :? lost me after "warning could be long winded"
dont get me wrong , not picking on you inc just totally confused!
now even more so, so is back at 57600,whatever!!!!as long as this damm confuser works i dont really give a ****!!!! :? 8O

i thought it might.

just imagine you are filling 14 paint tins the logic might work for you then [img]style_emoticons/<#EMO_DIR#>/tongue.gif[/img]