Assignment 1

Measure the latency and throughput of TCP and/or UDP (as noted below) across at least three pairs of machines using at least two different networks. For example, two CS servers (like rho and pi), or a CS server to a laptop, wired or wireless, or off-campus. Create a web page with graphs summarizing your results. All messages must use xor encoding of 64bit (8 byte, java "long") values, based on a (possibly random) key, and validated by the receiver. Include the following measurements:

Measure round-trip latency (RTTs) and how it varies with message size in TCP, by sending and receiving (echoing and validating) messages of size 8, 32, 512, and 1024 bytes.
The same as (1), except using UDP.
Measure throughput (bits per second) and how it varies with message size in TCP, by sending 1MByte of data (with a 8-byte acknowledgment in the reverse direction) using different numbers of messages: 1024 1024Byte messages, vs 2048 512Byte messages, vs 8192 X 128Byte messages.
The same as (3), using UDP.

For timing, use System.nanoTime (or the closest equivalent if using other languages). Read through the Java networking tutorial. Also see SimpleService.java and EchoClient.java for some stripped-down examples of using server and client sockets. When using non-CS machines and networks, minimize unnecessary traffic while developing your programs. Beware of firewalls.

Doug Lea