Need help regarding MTU, MCC, ICMP Headers ... !!!

Hello !!

I'm trying to set the MTU value of a new PC -- dual boot, Linux & Windows -- and the lan card, the adsl modem, etc.

Since I'm not so bright, I went online to check. The more I check, however, the more I got confused.

On this page

( scrolling down to #5 where it ) says "Add 28 to that number (IP/ICMP headers) to get the optimal MTU setting"

On this page,

however, ( scrolling down to TCPWindowSize ) it is telling me that "MSS is generally MTU - 40 (20 byte TCP and 20 byte IP headers)" !

Which one is correct?

Just exactly how much do all the headers add on to a packet?

28 bytes or 40 bytes??

Let's say I've done the "MTU Ping Test" to various websites, and has obtained 1452 as _the_ optimum number. My question is this ---

What's the correct MTU setting?

Is it 1480 (1452 + 28) ? or Is it 1492 (1452 + 40) ?

In Windows, what numer should I set for the TCPWindowSize, the GlobalMaxTcpWindowSize, the TcpWindowSize and so on?

Is the MTU value the same for Linux, Solaris and Windows??

Please help !!

Thank you !