Setup guide

Glossary
GL-3
Cisco 6400 Software Setup Guide
OL-1183-04
C
CBOS Cisco Broadband Operating System. The common operating system for DSL CPE, including the Cisco
675, the Cisco 675e, the Cisco 676, and the Cisco 677.
CBR
constant bit rate. QoS class defined by the ATM Forum for ATM networks. CBR is used for
connections that depend on precise clocking to ensure undistorted delivery. Compare with ABR, UBR,
and VBR.
CEF Cisco Express Forwarding. Advanced Layer 3 IP switching technology that optimizes network
performance and scalability for networks with large and dynamic traffic patterns, such as the Internet,
on networks characterized by intensive Web-based applications, or interactive sessions.
CEMF Cisco Element Management Framework.
CHAP
Challenge Handshake Authentication Protocol. Security feature supported on lines using PPP
encapsulation that prevents unauthorized access. CHAP does not itself prevent unauthorized access; it
merely identifies the remote end. The router or access server then determines whether that user is
allowed access. Compare to PAP.
CiscoFusion Cisco internetworking architecture that “fuses” together the scalability, stability, and security
advantages of the latest routing technologies with the performance benefits of ATM and LAN
switching, and the management benefits of VLANs. See also Cisco IOS.
Cisco IOS Cisco system software that provides common functionality, scalability, and security for all products
under the CiscoFusion architecture. Cisco IOS allows centralized, integrated, and automated
installation and management of internetworks, while ensuring support for a wide variety of protocols,
media, services, and platforms. See also CiscoFusion.
CLEC
competitive local exchange carrier. Company that builds and operates communication networks in
metropolitan areas and provides its customers with an alternative to the local telephone company.
CLI command-line interface. An interface that allows you to interact with the operating system by entering
commands and optional arguments. Compare with GUI.
CO central office. Local telephone company office to which all local loops in a given area connect and in
which circuit switching of subscriber lines occurs.
CPE
customer premises equipment. Terminating equipment, such as terminals, telephones, and modems,
supplied by the telephone company, installed at customer sites, and connected to the telephone
company network.
CRC cyclic redundancy check. Error-checking technique in which the frame recipient calculates a remainder
by dividing frame contents by a prime binary divisor and compares the calculated remainder to a value
stored in the frame by the sending node.