Technology content trusted in North America and globally since 1999
8,228 Reviews & Articles | 62,373 News Posts

Broadband Connection Tweaking Guide

By: TweakTown Staff | Guides | Posted: Aug 24, 2001 4:00 am

Tweaking RWIN (TCP receive window)


Open Dr. TCP and tab to the TCP receive window section. Type the corresponding RWIN matching your download speed in the TCP receive window box and press apply, exit, and re-boot. Remember that the RWIN is the single most important tweak setting that will make a difference. An RWIN limits the amount of bandwidth sent to a user in the downstream direction. Rwin sizes:


1.5mbps: About 22000


1.0mbps: About 11000


768kbps: About 10000


512kbps: About 8000


384kbps: About 6000


256kbps: About 4000


Of course you may want to experiment with different rwin sizes to see what difference in makes! Now, go do a speed test and you may see a big or small increase in download speed!!!


Tweaking TTL (Time to Live)


Every packet you send has an TTL attached to it that makes it expire after a certain number of hops, such as 64. Windows 98 has a 128 TTL default. People wonder if a lower TTL can improve connection stability. The answer is hard to tell. It may help, but I doubt you will notice any difference. However, there are a certain things you may want to know. How to change TTL? Open Dr. TCP and look for it on the top right!


1) If you are surfing a lot of websites that are VERY far away from you (international), then you may want to try an TTL of 255 if some websites won't load for you.


2) If you are surfing a lot of websites that are national (In the US), then you may want to try an TTL of 128 or 64. Try to not use 32 since the Internet is international…and not a network designed for your town. ;)


Tweaking Max Duplicate Acks


This setting gives you the option to set the maximum number of packets that should be resent if a packet is dropped. Microsoft tried to achieve an optimal number for Windows 98, which is 3 by default installation, and 2 for Windows 2000. You may want to try 2 if you do NOT experience packet loss in audio or video streams on the Internet, AND Internet games.


Tweaking Windows Scaling


Scaling is needed to enter any RWIN 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).


Tweaking Time Stamping (Attention satellite users)


The need for this seems to be in question, at least with RWIN under 65535. If you have a line where your latency (or ping) varies a lot, or a "long fat pipe" (for example, pure satellite connection), then Time stamping should be beneficial, so give time stamping a try. Time Stamping defaults to off (No).


Tweaking 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 (sorry Windows 95 and NT users, time to upgrade!). ;)


Tweaking 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.


Tweaking Black Hole Detection


This discovers routers on the WEB that cause MTU Discovery to work sub-optimally. Do not turn this on! Turn it off. Defaults to off (No) in Win95/98/98SE/ME/2K.


Tweaking ICS (Internet Connection Sharing)


This option is enabled only if you are sharing your connection with another computer. ICS is a program used by some who do not have a router. 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.




Now that you are done, go ahead and reboot! Enjoy the new speeds!!! ICQ me at if you would like to know also how to speed up your browsing speed in Internet Explorer. I hope you enjoyed this guide and will come back for more. Till then, make sure you break before every turn!


    PRICING: You can find products similar to this one for sale below.

    United States: Find other tech and computer products like this over at Amazon's website.

    United Kingdom: Find other tech and computer products like this over at Amazon UK's website.

    Canada: Find other tech and computer products like this over at Amazon Canada's website.

    We at TweakTown openly invite the companies who provide us with review samples / who are mentioned or discussed to express their opinion of our content. If any company representative wishes to respond, we will publish the response here.