Appendix D Common Services

Table 238 Commonly Used Services (continued)

NAME

PROTOCOL

PORT(S)

DESCRIPTION

 

 

 

 

TELNET

TCP

23

Telnet is the login and terminal emulation

 

 

 

protocol common on the Internet and in

 

 

 

UNIX environments. It operates over TCP/

 

 

 

IP networks. Its primary function is to allow

 

 

 

users to log into remote host systems.

TFTP

UDP

69

Trivial File Transfer Protocol is an Internet

 

 

 

file transfer protocol similar to FTP, but

 

 

 

uses the UDP (User Datagram Protocol)

 

 

 

rather than TCP (Transmission Control

 

 

 

Protocol).

VDOLIVE

TCP

7000

Another videoconferencing solution.

 

 

 

 

656

 

ZyWALL 2 Plus User’s Guide