Carrier Access CMG Router - Manual (Page 281)

CMG Router - Release 2.7 Glossary - 3
Glossary
DTMF Dual Tone Multi-Frequency is the system used by touch-tone telephones.
DTMF assigns a specific sound frequency, or tone, to each key so that it
can easily be identified by a monitoring microprocessor. That frequency
is then translated into a usable analog or digital signal. This is commonly
known as Touch Tone.
Ethernet Ethernet is a particular network topology and protocol, especially useful
in LANs. It comes in various speeds and is often regarded as THE current
technology for general network direct connection. The current
connectivity is generally considered to be 10Base-T or 100Base-T, while
the backbone, if one is used, is coaxial cable or Fiber optics. There is also
a 1000Base-T for certain specialty copper joining situations.
filter An operating parameter used with routers that can be set to block the
transfer of packets from one LAN to another.
firewall A system designed to prevent unauthorized access to or from a private
network. Firewalls can be implemented in both hardware and software,
or a combination of both. Firewalls are frequently used to prevent
unauthorized Internet users from accessing private networks connected
to the Internet, especially intranets. All messages entering or leaving the
intranet pass through the firewall, which examines each message and
blocks those that do not meet the specified security criteria.
frame A fragment of data that is packaged into a frame format, which comprises
a header, payload, and trailer.
frame relay A packet-switching protocol for connecting devices on a Wide Area
Network (WAN). Frame Relay networks in the U.S. support data transfer
rates at T1 (1.544 Mbps) and T3 (45 Mbps) speeds. Most telephone
companies now provide Frame Relay service for customers who want
connections at 56 Kbps to T1 speeds. However, it is being replaced in
some areas by faster technologies, such as ATM.
gateway A link from one computer system to a different computer system.
GMT Greenwich Mean Time.