On Wed, 2005-05-04 at 13:53 -0700, Joseph Kim wrote:
And, for my own curiosity, I tried to compare the throughputs between using zorp and without using zorp. In one configuration, I download a webpage 100 times through the machine with zorp running. In other configuration, I download the same webpage 100 times directly from our internet gateway router without going through the zorp machine.
To my surpise, I got the following results:
Each test includes 100 downloads.
Test # Average throughput Configuration Zorp Direct 1 737.4 Kbps 642.7 Kbps 2 711.7 Kbps 646.9 Kbps 3 721.6 Kbps 615.7 Kbps
According to the result, zorp actually made the connection faster. What kind of magic are you guys playing?
It is probably some kind of measuring problem, something changed between the two test invocations, and the test program might also be fooled somewhat (it depends on when the timer is started). For example if it is started after the HTTP response is received, Zorp does not send the HTTP header as long as the first real data byte is received from the server and then it is sent immediately together with the HTTP header. E.g: where a server would: client server GET -> <- HTTP/1.0 200 OK some time <- first data bytes Zorp converts this to: client Zorp server GET -> -> <- HTTP/1.0 200 OK some time <- first data bytes <- HTTP/1.0 200 OK <- first data bytes If the timer starts when the header is received then the actual bandwidth calculated might differ from the case where no Zorp is present. But of course it does not change reality, Zorp is an additional processing burden, thus it effectively has to increase network latency. For deployments where the proxies are not overloaded (and a 1MBit connection does not overload a current box), the latency change should be minimal. -- Bazsi