C-6
Glossary
POP "Post Office Protocol"
A TCP/IP-based protocol designed to allow client-stations (e.g. micros) to
read mail from a server. There are three versions under the name "POP":
POP, POP2, and POP3. Latter versions are NOT compatible with earlier
versions.
Protocol
The "rules" by which two network elements trade information in order to
communicate. Must include rules about a lot of mundane detail as well as
rules about how to recover from a lot of unusual communication problems.
Thus they can be quite complicated.
Relay
One terminology uses the term "relay" as a device that interconnects LANs,
different kinds of relays being repeaters, bridges, routers, and gateways.
Repeater
In the "Ethernet" world, a "relay" that regenerates and cleans up signals, but
does no buffering of data packets. It can extend an Ethernet by strengthening
signals, but timing limitations on Ethernets still limit their size.
Router
A network "relay" that uses a protocol beyond the data-link protocol to route
traffic between LANs and other network links.
Routing Protocol
A protocol sent between routers by which routers exchange information on
how to route to various parts of the network. The TCP/IP family of protocols
has a bunch, such as RIP, EGP, BGP, OSPF, and dual IS-IS.
Shielded Twisted Pair
A type of twisted-pair cable with a metallic shield around the twisted
conductors. The shield reduces the noise from the cable and reduces the
effects of noise on the communications in the cable, but changes the
electrical characteristics of the cable so some equipment optimized to non-
shielded cable does not run as efficiently using shielded cable.
Single Mode fiber
A type of fiber optic cable used for longer distances and higher speeds, e.g.
for long-distance telephone lines. See also "Multimode Fiber".
SMTP "Simple Mail Transfer Protocol"
The protocol in the TCP/IP family used to transfer electronic mail between
computers. It is not oriented towards a client/server system so other protocols