Westermo RM-80 - Manual (Page 51)

51 6193-4201
CSMA/CD A method of managing traffic and reducing noise on an Ethernet
network. A network device transmits data after detecting that
a channel is available. However, if two devices transmit data
simultaneously, the sending devices detect a collision and retransmit
after a random time delay.
DHCP A utility that enables a server to dynamically assign IP addresses
from a predefined list and limit their time of use so that they can be
reassigned. Without DHCP, an IT Manager would have to manually
enter in all the IP addresses of all the computers on the network.
When DHCP is used, whenever a computer logs onto the network,
it automatically gets an IP address assigned to it.
Dial-up A communication connection via the standard telephone network, or
Plain Old Telephone Service (POTS).
DNS A program that translates URLs to IP addresses by accessing a
database maintained on a collection of Internet servers. The program
works behind the scenes to facilitate surfing the Web with alpha
versus numeric addresses. A DNS server converts a name like
mywebsite.com to a series of numbers like 107.22.55.26. Every
website has its own specific IP address on the Internet.
DSL Various technology protocols for high-speed data, voice and video
transmission over ordinary twisted-pair copper POTS (Plain Old
Telephone Service) telephone wires.
Encryption key An alphanumeric (letters and/or numbers) series that enables data
to be encrypted and then decrypted so it can be safely shared
among members of a network. WEP uses an encryption key that
automatically encrypts outgoing wireless data. On the receiving side,
the same encryption key enables the computer to automatically
decrypt the information so it can be read.
Firewall Keeps unauthorized users out of a private network. Everything
entering or leaving a system’s internal network passes through the
firewall and must meet the system’s security standards in order to
be transmitted. Often used to keep unauthorized people from using
systems connected to the Internet.
Hub A multiport device used to connect PCs to a network via Ethernet
cabling or via WiFi. Wired hubs can have numerous ports and can
transmit data at speeds ranging from 10 Mbps to multigigabyte
speeds per second. A hub transmits packets it receives to all the
connected ports. A small wired hub may only connect 4 computers; a
large hub can connect 48 or more.