Glossary
Multi-Tech Systems, Inc. RF560VPN User Guide
79
NetworkAddress
The network portion of an IP address. For a class A network, the network address is the first byte
of the IP address. For a class B network, the network address is the first two bytes of the IP
address. For a class C network, the network address is the first three bytes of the IP address. In
each case, the remainder is the host address. In the Internet, assigned network addresses are
globally unique.
P
Packet
A packet is a piece of a message transmitted over a packet-switching network. A packet contains
the destination address of the message as well as the data. In IP networks, packets are often
called datagrams.
PING
A program that tests whether a particular network destination on the Internet is online (that is,
working) by bouncing a “signal” off a specified IP destination address.
Port Number
The term
port
can mean the connector on your computer or it can be thought of as a server
number. Every service that travels over phone lines and modems has a standard port number. For
example, the World Wide Web service uses the standard port number,
80
and the standard Telnet
port is
23
.
Port numbers are controlled and assigned by the IANA (Internet Assigned Numbers Authority).
Most computers have a table in their systems containing a list of ports that have been assigned to
specific services. You can also find lists of standard port numbers on the World Wide Web.
PPPoE
Point-to-point protocol over the Ethernet. It is a means of connecting from your premises to your
Internet Service Provider. Its main advantage is that it determines the need for the ISP to manage
the allocation of IP addresses.
PPTP
Point-to-Point Tunneling Protocol – An IP tunneling protocol designed to encapsulate the LAN
protocols IPX and Apple Talk within IP for transmission across the Internet and other IP-based
networks.
Private Key
Key used in public key crypto that belongs to an individual entity and must be kept secret.
Protocol
A formal description of message formats and the rules two computers must follow to exchange
those messages. You can think of protocols like languages. If two computers or devices aren’t
speaking the same language to each other, they won’t be able to communicate.
PPP (Point -to- Point Protocol
)
PPP enables dial-up connections to the Internet and is the method that your network device
connects to the Internet. PPP is more stable than the older SLIP protocol and provides error
checking features.
R
Router
A device which forwards traffic between networks. If you request information from a location on
your network or the Internet, the router will route the request to the appropriate destination. The
router’s job is to listen for requests for IP addresses that are not part of your LAN and then route
them to the appropriate network which may either be the Internet or another sub-network on your
LAN.