Appendix A - Troubleshooting
91
ISP:
Internet Service Provider. An ISP is a business that provides connectivity to the Internet
for individuals and other businesses or organizations.
LAN:
Local Area Network. A LAN is a group of computers and devices connected together in
a relatively small area (such as a house or an office). Your home network is considered a LAN.
MAC Address:
MAC stands for Media Access Control. A MAC address is the hardware
address of a device connected to a network. The MAC address is a unique identifier for a
device with an Ethernet interface. It is comprised of two parts: 3 bytes of data that corresponds
to the Manufacturer ID (unique for each manufacturer), plus 3 bytes that are often used as the
product
’
s serial number.
NAT:
Network Address Translation. This process allows all of the computers on your home
network to use one IP address. Using the broadband 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 applica-
tion/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
PPPoE:
Point-to-Point Protocol over Ethernet. Point-to-Point Protocol is a secure data trans-
mission method originally created for dial-up connections; PPPoE is for Ethernet connections.
PPPoE
relies on two widely accepted standards, Ethernet and the Point-to-Point Protocol. It is a
communications protocol for transmitting information over Ethernet between different manu-
facturers
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.
Router:
A router is an intelligent network device that forwards packets between different
networks based on network layer address information such as IP addresses.
