42 Aurorean Network Gateway-1100 User’s Guide
Appendix A
Glossary
authentication server (such as a RADIUS or SecurID server). When the
network administrator changes tunnel connection parameters, the Aurorean
Policy Server provide updated configuration files to Aurorean Network
Gateways on request.
DHCP
Dynamic Host Configuration Protocol (DHCP) servers are used to assign IP
addresses. The Aurorean Network Gateway-1 102/1 10 5 is capabl e of assigni ng
IP addresses.
DSL
Refers to Digital Subscriber Lines. DSL technologies use sophisticated
modulation schemes to pack data onto copper wires. They are sometimes
referred to as last-mile technologies because they are used only for
connections from a telephone switching station to a home or office, not
between switching stations. Usually the maximum distance between the
home or office and the switching station has to be around one mile.
Ethernet
The Ethernet originated in 1974 by Xerox to connect many office machines
together to allow communications between them. Coax cable was originally
used. today twisted pair wire can be used and the speeds can be up to 10
megabits per second.
Firewall
A combination of hardware and software which limits the exposure of a
corporate network to outside attack by enforcing a boundary between the
network and the Internet. Firewalls normally fall into one of two categories:
application-level or network-level (often referred to as a packet filter). An
application-level firewall examines traffic at the application level, and only
passes packets that are sent by approved applications (such as FTP, E-mail, or
Telnet). This type of firewall often readdresses outgoing traffic so that it
appears to have originated at the firewall rather than an internal host, thereby
concealing the address of the internal host. A network-level firewall examines
traffic at the network packet level, and filters packets based on the destination
and/or source address.