User manual

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NAT
Network Address Translator is defined by RFC 1631. Enable a LAN network to
use one set of IP address for internal traffic. A NAT box located where the LAN
meets the Internet provides the necessary IP address translation. This helps
provide a sort of firewall and allow for a wider address range to be used internally
without danger of conflict. Using the router’s NAT capability, you can access the
Internet from any computer on your home network without having to purchase
more IP addresses from your ISP.
Port
Network Clients (LAN PC) uses port numbers to distinguish one network
application/protocol over another. Below is a list of common applications and
protocol/port numbers:
Application Protocol Port Number
Telnet TCP 23
FTP TCP 21
SMTP TCP 25
POP3 TCP 110
H.323 TCP 1720
SNMP UCP 161
SNMP Trap UDP 162
HTTP TCP 80
PPTP TCP 1723
PC Anywhere TCP 5631
PC Anywhere UDP 5632
PPP
PPP is the Point-to-Point-Protocol. The successor to SLIP, PPP provides router-
to-router and host-to-network connections over both synchronous and
asynchronous circuits.