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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.

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PPPoA (RFC 2364)

The Point-to-Point Protocol (PPP) provides a standard method for transporting

multi-protocol data grams over point-to-point links. This document describes the

use of ATM Adaptation Layer 5 (AAL5) for framing PPP encapsulated packets.

PPPoE (RFC 2516)

This document describes how to build PPP sessions and encapsulate PPP

packets over Ethernet. PPP over Ethernet (PPPoE) provides the ability to

connect a network of hosts over a simple bridging access device to a remote

Access Concentrator.

Protocol

A protocol is a set of rules for interaction agreed upon between multiple parties

so that when they interface with each other based on such a protocol, the

interpretation of their behavior is well defined and can be made objectively,

without confusion or misunderstanding.

PVC

Permanent Virtual Circuit, connection-oriented permanent leased line circuit

between end-stations on a network over a separate ATM circuit.

RFC

Request for Comments. The document series, begun in 1969, which describes

the Internet suite of protocols and related experiments. Not all RFCs describe

Internet standards, but all Internet standards are written up as RFCs.

RFC 1483

Multi-protocol encapsulation over AAL-5. Two encapsulation methods for carrying

network interconnect traffic over ATM AAL-5. The first method allows multiplexing

of multiple protocols over a single ATM virtual circuit. The protocol of a carried

PDU is identified by prefixing the PDU by an IEEE 802.2 Logical Link Control

(LLC) header. This method is in the following called "LLC Encapsulation". The

second method does higher-layer protocol multiplexing implicitly by ATM Virtual

Circuits (VCs). It is in the following called "VC Based Multiplexing".

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Router

A system responsible for making decisions about which of several paths network

(or Internet) traffic will follow. To do this, it uses a routing protocol to gain

information about the network and algorithms to choose the best route based on

several criteria known as "routing metrics.

Subnet Mask

A subnet mask, which may be a part of the TCP/IP information provided by your

ISP, is a set of four numbers (e.g. 255.255.255.0) configured like an IP address.

It is used to create IP address numbers used only within a particular network (as

opposed to valid IP address numbers recognized by the Internet, which must be

assigned by InterNIC).

TCP/IP, UDP

Transmission Control Protocol/Internet Protocol (TCP/IP) and Unreliable

Datagram Protocol (UDP). TCP/IP is the standard protocol for data transmission

over the Internet. Both TCP and UDP are transport layer protocol. TCP performs

proper error detection and error recovery, and thus is reliable. UDP on the other

hand is not reliable. They both run on top of the IP (Internet Protocol), a network

layer protocol.

TELNET

It is the virtual terminal protocol in the Internet suite of protocols. Allows users of

one host to log into a remote host and act as normal terminal users of that host.

VCI

Virtual Circuit Identifier is part of the ATM cell header. A VCI is a tag indicating

the channel over which a cell will travel. The VCI of a cell can be changed as it

moves between switches via Signaling.

VPI

Virtual Path Identifier is part of the ATM cell header. A VPI is a pipe for a number

of Virtual Circuits.

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WAN

Wide Area Network is a network that connects computers located in

geographically separate areas (e.g. different buildings, cities, countries). The

Internet is a wide area network.

Web-based management Graphical User Interface (GUI)

Many devices support a graphical user interface that is based on the web

browser. This means the user can use the familiar Netscape or Microsoft Internet

Explorer to Control/configure or monitor the device being managed.

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