These are some explanations of the settings in Dr. TCP (according to a FAQ at dslreports.com): Also check hxxt://www.dslreports.com/tweaks
"TCP Receive Window: This is where you set RWIN (RcvWindow). RWIN is the single most important tweak. Raising Rwin from default (8760 for Win95/98/98SE/NT and 17520 for WinME/2K/XP), can greatly improve download speeds. Why? Here is my kindergarten analogy: Default RWIN for broadband, is like having a tiny straw in a thick milk shake, only so much can get through the straw (line), so fast. By putting a larger straw (higher RWIN) in that same thick shake, you allow more shake (data) to come through faster, to a point that is. After which, there is no more improvement, and shake (data) can start spilling all over (packet loss). So the key is, to find an RWIN that fits your line just right. This is blank before changing from default.
The formula for finding your "ideal" RWIN, is to take your latency (average ping time in ms x 1.5), multiply it by your proposed speed, and divide that by 8.
Note: If setting RWIN below 8192, try using even multiples of MSS.
Windows Scaling : 65535 is the highest RWIN you can use without Windows Scaling being turned on. So simply put, Scaling is needed to enter any number higher than 65535. However, you must also have the updated vtcp.386 patch (WinME/2K does not need a patch). Relax though, most users do not need to go higher than 65535. Windows Scaling defaults to off (No).
Time Stamping : The need for this seems to be in question, at least with RWIN under 65535. If you have a line where latency varies a lot, or a "long fat pipe" (for example, pure satellite connection), then Time stamping should be beneficial, so experiment with it. Time Stamping defaults to off (No).
Selective Acks: This improves throughput (speed) on lines that tend to lose packets, by re-transmitting only packets that were lost, if any. Defaults to on (Yes) in Win98/98SE/ME/2K and is N/A in Win95/NT.
Path MTU Discovery : This automatically sets your MTU (maximum transmission unit) to what type of line you have (dial-up (576), broadband). This is the size of packets that you can receive. The highest MTU that one can have is 1500. For users with PPPoe connection software, 1492 and lower. Defaults to on (Yes)in Win98/98SE/ME/2K/NT, and is N/A in Win95.
Black Hole Detection: This discovers routers on the WEB that cause MTU Discovery to work sub-optimally. Defaults to off (No) in Win95/98/98SE/ME/2K
Max. Duplicate ACKs: This allows for faster re-transmission of packets (information), when packet loss is encountered. Defaults to blank, where blank stands for 3 in Win98/98SE/ME, 2 in WinNT/2K, and is N/A in Win95.
TTL : Time To Live is the amount of hops (servers) that a transmission of packets will take before all packets are lost. If you were receiving packets from 20 hops away, and TTL was set to 19 or less, all packets would be lost before they reach you. Not a speed tweak. Defaults to blank, where blank stands for 32 in Win95, 128 in Win98/98SE/ME/2K.
Adapter settings: This is where you set your MTU. (Defaults to dial-up adapter when opened. This has nothing to do with the settings on top). Use the drop-down menu to find your NIC (Ethernet card). If you do not know which adapter you should set, please ask. Do not set them all the same. (Note: Only physical NICs supported for Win2K/XP, no dial-up adapters.)
Note: DRTCP defaults to showing the dial-up adapter. This has nothing to do with the other settings.
ICS Settings: Internet MTU is set when Internet Connection Sharing (a Microsoft program) is enabled and being used on your PC. This is where 2 or more PCs share the same Internet connection, though only one can surf at a time. ICS MTU should match that of the PC. This is grayed out if ICS is not being used (not ready for Win2K).
Also: By right clicking on the logo and choosing "About", you will find information about the version of Windows you use."
[quote:0ae1122211][i:0ae1122211]Originally posted by Homeless4ever [/i:0ae1122211]
[b]Umm...Can you explain what does all those do?
[/quote:0ae1122211]