Range Description
--------- ------------------------------------------------------
2000 normal TELNET (full options negotiations, remote echo)
see RFC-854, also stuff on TELNET in RFC-1123
3000 normal TELNET to rotary
4000 raw TCP (stream) - no TELNET NVT. See RFC-793.
5000 raw TCP (stream) to rotary
6000 TELNET binary mode - see RFC-856
7000 TELNET binary mode to rotary
8000 forward Xremote
9000 reverse Xremote
10000 reverse Xremote to rotary
telnet = CR LF
binary = CR NULL 6000
stream = No negotiations 4000
Stream would usually be to a printer; binary would usually be to a host application that is running.