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ZyXEL Communications ZyWALL 2 Plus User Manual

Page 656

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Appendix D Common Services

ZyWALL 2 Plus User’s Guide

656

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.

Table 238 Commonly Used Services (continued)

NAME

PROTOCOL

PORT(S)

DESCRIPTION