B-10
Appendix B: Glossary
included in the CIDR address. Lower numbers include more addresses. An IP
network prefix of /12, for example, can be used to specify 1,048,576 former
Class C addresses. CIDR addresses reduce the size of routing tables and make
more IP addresses available within organizations. For more information about
CIDR, see RFC 1519 (at http://www.ietf.org/rfc/rfc1519.txt).
Cipher Text Encrypted data.
CIR Committed Information Rate. For Frame Relay networks, the CIR is the
bandwidth that the carrier guarantees to be available for a particular PVC
under normal circumstances. Typically, the CIR is specified in the Frame Relay
SLA. See also EIR, Frame Relay, PVC, and SLA.
Circuit-Level
Gateways
This type of firewall operates at the OSI Session Layer. Circuit-level gateways
monitor TCP handshakes between packets from trusted clients or servers to
untrusted hosts (and vice versa) to determine whether a requested session is
legitimate. The session is legitimate only if the SYN flags, ACK flags, and
sequence numbers involved in the TCP handshakes are logical.
Clear Text Unencrypted text.
CLEC Competitive Local Exchange Carrier. In the United States and Canada, a CLEC
is a company that competes with the already established local telephone
business by providing its own network and switching. The term distinguishes
new or potential competitors from established local exchange carriers. The
existence of CLECs arises from the Telecommunications Act of 1996, which
was intended to promote competition among both long-distance and local
phone service providers.
CLI Command Line Interface. The interface that allows an administrator to enter
line commands to interact with and configure the router.
CO Central Office. The service provider’s office to which a subscriber’s home and
business lines are connected through the local loop. The CO has equipment
that can switch calls locally or to long-distance carrier phone offices.
Coaxial Cable This cable consists of a center wire that is surrounded by insulation, which is
encased in a grounded shield of braided wire. The shield minimizes electrical
and radio frequency interference.
Compression The process of reducing information size or transmission bulk without
affecting information content.
Configure To define the parameter values that allow network equipment to run in the
manner required for a particular environment.
To Next Page
Loading...
Need help?
General
