Re: Throughput Formula

tyates@xxxxxxxxxxx wrote:
Need some help. Trying to find a formula or program if a free on
exists to calculate network throughput. I need something that will
allow me to use latency as a variable as most online calculators
assume the best latency.

Tput <= Weff/RTT

Where Weff is the "effective window" which will be the lesser of:

a) The TCP window advertised by the receiver
b) The SO_SNDBUF size on the sender
c) The sending TCP's calculated congestion window
d) The most data the sending application will send at one time

For example, I'd like to know how long it would take to transfer:
. a 1GB file
. both sending and receiving side are gigabit ethernet
. point to point using either OC3, OC12, OC48 or OC192
. various latency values, 4ms thru 30ms

Which file transfer protocol? FTP will behave differently than say
CIFS or NFS particularly with respect to 'd' above.

rick jones
ftp://ftp.cup.hp.com/dist/networking/briefs/SE_372_2_99.ps.gz
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