From what I've been told/understand Ron, this is the deal.
Every packet has a header that "identifies" it so to speak. I.E. one packet says "I'm an incoming packet from this place" and the other packet says "I'm an incoming packet from that place", so IP headers allow you to do all these great things like download a file, load a web page, and run a chat client all at the same time by allowing you to handle multiple packets simultaneously. If I remember correctly someone told me it was a Novell idea years back to compress these headers, to use less bandwidth and increase throughput on LAN setups. Since then ISP's have taken up this method with dial up connections to improve speed for dial up users.
With this in mind, we can apply the same theory to header compression as v34/v90. Less compression equals lower ping times, due to less waiting for de-compression by your machine. I assume this recommendation comes from gamers, who must at all costs see that ping rate 5ms lower, whether it really improves their speed or not
.
Everything else being equal, though, I think the benefits from this setting would be minimal, and depending on how your ISP works network protocols disabling this might not even work with any stability at all. I've personally had great results with gaming by limiting my modem to a rock solid speed that my line can handle, and setting packet size to small on the dial up adapter.
Any network gurus feel free to set me straight here, but from my understanding of IP headers, you wanna leave compression enabled.
The problems with modem speed IMHO are encompassed completely by the myths out there about data compression. Dial Up users, and gamers especially, want fast gaming performance, as well as super high initial connect speeds. This is completely contradictory. On the average phone line, a faster initial connect speed will mean worse game performance from my experience. For example, if your phone line and your ISP can give you a solid 44k connection and your do everything in your power to eek it up to 49k, you're gonna cripple overall performance. Average out those retrains and lost packets and you'll be better off with the 44k 99 times out of 100, and especially with gaming.
Basically there's a set of things you have to consider to optimize a modem connection. Method of connection, modem type/quality, and application.
If you're using a Winmodem on AOL trying to play Quake, you need to consider a VERY fast processor or bumping down to v34. With that 60% processor usage going on you'll lag terribly anyways, so best to limit what you can, which in this case would be the modem. If you're just web surfing/downloading, let Kflex or V90 go, since the average retrain or spot of lag won't matter.
If you're using DUN to connect with a Hard modem, find a good solid speed by limiting your modem a bit and stick with it. Processor usage from DUN and a hard modem connection shouldn't be more than 10%, so you can afford a little more speed from the modem, since your processor doens't have to pull the compression/decompression load. Modem does it's thing, processor/video card handle the game, all should be well. If you're just surfing with a Hard modem and DUN, by all means, crank it up
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If using a USB modem, see the above paragraph on Winmodems for gaming purposes
. If just surfing, again, doesn't really matter.
I personally use two different sets of strings and settings with my Diamind Supra ISA. One for gaming, one for surfing/downloading. It's not as simple as the speed that DUN shows you when you connect.
Bottom line after this lengthy rant is if you really need more speed from your dial up connection, header compression and packet sizes are rather miniscule settings. I'll wager that in 99% of all PC setups there's something else that causes modem speed bottlenecks besides packet sizes and compressed headers.
Xayd
[This message has been edited by Xayd (edited 06-26-2000).]