The tcpsplit utility breaks a single libpcap packet trace into some number
of sub-traces, breaking the trace along TCP connection boundaries so that
a TCP connection doesn't end up split across two sub-traces. This is useful
for making large trace files tractable for in-depth analysis and for
subsetting a trace for developing analysis on only part of a trace.

WWW: http://www.icir.org/mallman/software/tcpsplit/