Deostroll,
Probably the first thing you can do is use Wireshark or tshark instead of tcpdump to capture and view your data. This will give you a better decoded view of what is going on. Secondly if you do want to understand how the Telnet or protocols work you really need to start reading some references. You could start at wikipedia or google for "tcp protocol explained". There are also some good books available at good bookstores or technical college libraries.
Regards, Martin
MartinVisser99@xxxxxxxxx