tcpflow -- Network traffic recorder
http://www.circlemud.org/~jelson/software/tcpflow/
tcpflow is a program that captures data transmitted as part of TCP
connections (flows), and stores the data in a way that is convenient for
protocol analysis or debugging. A program like 'tcpdump' shows a summary
of packets seen on the wire, but usually doesn't store the data that's
actually being transmitted. In contrast, tcpflow reconstructs the actual
data streams and stores each flow in a separate file for later analysis.