Reverse Telnet to Async Ports

[d-rathman]

We have a Cisco router configured with a 32-port async card. We use it as a terminal server to connect to a Nortel DMS100 phone switch. Currently we reverse telnet to port 3001, 3002, etc. depending on the rotary group we want to hit. What is port 500X and 700X? I know port 5000 is for "raw TCP" and port 7000 is for telnet binary. What is an application where I would use raw tcp or telnet binary versus just regular telnet? I'm just trying to understand. Thanks!

[mljohnson]

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.