Glossary
EN/LZT 108 6492 R1 97 (98)
April 2003
PVC
Short for Permanent Virtual Circuit, which is a logical point-to-point circuit between
customer sites. PVCs are low-delay circuits because routing decisions do not need to
be made along the way. Permanent means that the circuit is preprogrammed by the
carrier as a path through the network. It does not need to be set up or disconnected for
each session.
RFC
Short for Request for Comments, a series of notes about the Internet, started in 1969
(when the Internet was the ARPANET). An Internet Document can be submitted to
the IETF by anyone, but the IETF decides if the document becomes an RFC.
Eventually, if it gains enough interest, it may evolve into an Internet standard.
Each RFC is designated by an RFC number. Once published, an RFC never changes.
Modifications to an original RFC are assigned a new RFC number.
RIP
Short for Routing Information Protocol, which is a protocol that specifies how routers
exchange routing table information. With RIP, routers periodically exchange entire
tables.
Router
A device that connects any number of LANs. Routers use headers and a forwarding
table to determine where packets go, and they use ICMP to communicate with each
other and configure the best route between any two hosts. Very little filtering of data
is done through routers. Routers do not care about the type of data they handle.
10BaseT
One of several adaptations of the Ethernet standard for Local Area Networks (LANs).
The 10Base-T standard (also called Twisted Pair Ethernet) uses a twisted-pair cable
with maximum lengths of 100 meters. Cables in the 10Base-T system connect with
RJ-45 connectors.
100BaseT
A networking standard that supports data transfer rates up to 100 Mbps (100 megabits
per second). 100BASE-T is based on the older Ethernet standard. Because it is 10
times faster than Ethernet, it is often referred to as Fast Ethernet.
TCP
Abbreviation of Transmission Control Protocol, and pronounced as separate letters.
TCP is one of the main protocols in TCP/IP networks. Whereas the IP protocol deals
only with packets, TCP enables two hosts to establish a connection and exchange
streams of data. TCP guarantees delivery of data and also guarantees that packets will
be delivered in the same order in which they were sent.
Telnet
A terminal emulation program for TCP/IP networks such as the Internet. The Telnet
program runs on your computer and connects your PC to a server on the network. You
can then enter commands through the Telnet program and they will be executed as if
you were entering them directly on the server console. This enables you to control the
server and communicate with other servers on the network. To start a Telnet session,
you must log in to a server by entering a valid username and password. Telnet is a
common way to remotely control Web servers.
