Appendix D Common Services
ZyWALL 2 Plus User’s Guide
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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
