Class based queueing

Class based queueing (class-based queueing, CBQ) is a network router queueing method that allows traffic to share bandwidth equally, after being grouped by classes. The classes can be based upon a variety of parameters, such as priority, interface, or originating program.

CBQ is a traffic management algorithm developed by the Network Research Group at Lawrence Berkeley National Laboratory as an alternative to traditional router-based technology. Now in the public domain as an open technology, CBQ is deployed by companies at the boundary of their WANs.

CBQ divides user traffic into a hierarchy of classes based on any combination of IP addresses, protocols and application types. A company's accounting department, for example, may not need the same Internet access privileges as the engineering department. Because every company is organized differently and has different policies and business requirements, it is vital for traffic management technology to provide flexibility and granularity in classifying traffic flows.

CBQ lets network managers classify traffic in a multilevel hierarchy. For instance, some companies may first identify the overall needs of each department or business group, and then define the requirements of each application or group of applications within each department. For performance and architectural reasons, traditional router-based queueing schemes are limited to a small number of classes and only allow one-dimensional classification.

Because it operates at the IP network layer, CBQ provides the same benefits across any Layer 2 technology and is equally effective with any IP protocol, such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). It also operates with any client or server TCP/IP stack variation, since it takes advantage of standard TCP/IP flow control mechanisms to control end-to-end traffic.


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Class-based queueing — (CBQ) is a network router queueing method that allows traffic to share bandwidth equally, after being grouped by classes. The classes can be based upon a variety of parameters, such as priority, interface, or originating program. CBQ is a traffic …   Wikipedia

  • Skills based routing — (SBR), or Skills based call routing, is a call assignment strategy used in call centres to assign incoming calls to the most suitable agent, rather than simply choosing the next available agent. It is an enhancement to the Automatic Call… …   Wikipedia

  • ALTQ — is an ALTernate Queueing framework for BSD UNIX. ALTQ provides queueing disciplines and other QoS related components required to realize resource sharing and Quality of Service. It is most commonly implemented on BSD based routers. ALTQ is… …   Wikipedia

  • ALTQ — Содержимое на этой странице, первоначально появились в FreeBSD man pages для ALTQ и pf.conf, и на оригинал ALTQ вебстраница. ALTQ это альтернативная платформа организации очередей для BSD. ALTQ обеспечивает организации очередей, и другиё QoS… …   Википедия

  • dSniff — Developer(s) Dug Song Stable release 2.3 / December 17, 2000; 10 years ago (2000 12 17) Operating system Unix like …   Wikipedia

  • Token bucket — A token bucket is a common algorithm used to control the amount of data that is injected into a network, allowing for bursts of data to be sent. Although it has several uses, it is best understood in the context of network traffic shaping or rate …   Wikipedia

  • Hierarchical Fair Service Curve — (HFSC) is based on a QoS and a CBQ algorithm which is used mostly on Unix operating systems. It is the first QoS algorithm to simultaneously support all three of real time, adaptive best effort, and link sharing services.Also used in NetBSD 1.2D …   Wikipedia

  • CBQ — may mean: * Catholic Biblical Quarterly * Chicago, Burlington and Quincy Railroad (AAR reporting mark CBQ) * Class based queueing * CBQ FM, a radio station in Thunder Bay, Ontario …   Wikipedia

  • CBQ — abbr. Class Based Queueing …   Dictionary of abbreviations

  • CBQ — abbr. Class Based Queueing …   United dictionary of abbreviations and acronyms


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.