[netperf-talk] Re: a simple question on the speed measurement

[Rick Jones]

Ming Liu wrote:
> Dear Rick,
> I have a simple question on the measurement of network speed. When 
> measuring with Netperf and the result shows like 300Mbps, is this speed 
> the physical or real speed appears on the wire, or the speed for data 
> which is sent into the socket? In detail and for example, if in a 
> second, 37.5 Mbytes date (37.5*8=300 Mbit) is sent into the socket and 
> goes out on the wire, what's the speed? If the pure data is used to 
> calculate, that should be 300Mbps. However, when the data goes through 
> the TCP/IP stack, headers of TCP/UDP and IP will be added and also 
> transmitted. So the physical or real speed appears on wire should be 
> more than 300Mbps, right? Which kind of value did you use in Netperf?
> Perhaps this question is stupid, but thank you so much for your telling.

The throughput reported by netperf is what is sent into/ received from
the socket.  It will _not_ include any protocol headers (TCP or UDP, IP,
Link)

happy benchmarking,

rick jones