here is some info lol from a online gameing site i understand some of it but not all of it
Dial-ups are definitely laggy. They introduce a 150-250ms lag (on a good line, good day, close to switch) because of the conversion, delay over the phone line, etc. On a bad day, when there's some line noise, error correction and retries can cause that to skyrocket on some packets. Remember, lagtimes are averaged and measured very infrequently relative to the number of packets set. When you're seeing 500, 1000, 1500+ ms lag times what you're often seeing is that the lag on << 1% of packets AVERAGES that. Imagine the distribution of times on the remaining 99%.
Sometimes setting a ceiling on modem connect speed can improve the consistency of that... i.e., if your 56k modem connects occassionally at 41+, but usually at 33.6 or 31.2, limit its connect speed to 33.6, 31.2, or a hair lower. Sometimes you'll see a substancially improved connection and transfer rates because the modem just barely managed to connect at the speed it did or it connected and line noise has since increased.
See a modem user black hat intermittently, frequently, and for random periods... it's usually line noise causing renegotiates and/or error correction.
Also, because of their poor speed, dial-ups have trouble handling the volume of data from a busy server. Start losing more and more udp packets, which are frequently lost, and people get really jumpy. UDP packets can arrive out of order too. Seen players driving forward but intermittently jumping back? Sometimes that's a correction to the dead-reckoning done on the client end, other times it's a udp packet that got delayed arriving late with out of date motion info. During spurts of data (quiet room and everyone starts shooting or using machine guns) you can overwhelm the modem and exacerbate this.
If I'm not mistaken, shrinking the packet size can often improve this for gaming, but it does so at the expense of download speed for files and larger chunks of information.
Modems aren't the only cause of lag tho, as all the net-savies can tell you. If a server seems laggy or players jumpy, then do a few tracerts to it after you've died. Often you'll find there's a slow hop, or one that's intermittently timing out. You can actually have great lag times showing but horrible game play if the 1% of packets measured for lag don't get caught by time outs but a few percent in between are delayed or lost.
And a not for all you cable modem users on 128k, 256k, 512kbps connections etc -cable modems achieve rate limiting by throttling. If the data being sent/received isn't near your cap then you've often got low lag and great transfers. Once it exceeds the rate you're allowed the cable modem throttles on and off. It sends full speed for a spurt, stops for bit, and repeats. You've probably noticed this when downloading a large file.
Well, if another player is downloading or uploading something while playing, their tank might seem to pause briefly then zoom thru the world as the stream of packets from their modem is unleashed full speed after a pause.