How to do calculations for performance tuning?

[S H A N]

hi,

reference to Kernel Tunable's section in FreeBSD handbook....

>>>>>
A simple calculation can be done to figure out how many are needed. If you have a web server which maxes out at 1000 simultaneous connections, and each connection eats a 16K receive and 16K send buffer, you need approximately 32MB worth of network buffers to cover the irc server. A
>>>>>

how can we find out that each HTTP (TCP) connection will eat up 16k recv. and 16k send buffer? and accordingly if they are talking about HTTP (TCP) connections then how we can establish the relevant figures for say a RADIUS (UDP) connection? what means/software/tools usually are out there to find out the utilization of buffer space for a single connection based on a particular application protocol... be it HTTP/SMTP/RADIUS etc...

hopefully i am writing to the right mailing list to inquire about all this!

rgds,

S H A N