WFQ
Weighted fair queuing (WFQ) is a data packet scheduling technique allowing different scheduling priorities to statistically multiplexed data flows.
WFQ is a generalization of fair queuing (FQ). Both in WFQ and FQ, each data flow has a separate FIFO queue. In FQ, with a link data rate of R, at any given time the N active data flows (the ones with non-empty queues) are serviced simultaneously, each at an average data rate of R/N. Since each data flow has its own queue, an ill-behaved flow (who has sent larger packets or more packets per second than the others since it became active) will only punish itself and not other sessions.
As opposed to FQ, WFQ allows different sessions to have different service shares. If N data flows currently are active, with weights w_1, w_2 ... w_N, data flow number i will achieve an average data rate of
\frac{Rw_i}{(w_1+w_2+...+w_N)}
It can be proven that when using a network with WFQ switches and a data flow that is leaky bucket constrained, an end-to-end delay bound can be guaranteed. By regulating the WFQ weights dynamically, WFQ can be utilized for controlling the quality of service, for example to achieve guaranteed data rate.
Proportional fairness can be achieved by setting the weights to w_i=1/c_i, where c_i is the cost per data bit of data flow i. For example in CDMA spread spectrum cellular networks, the cost may be the required energy (the interference level), and in dynamic channel allocation systems, the cost may be the number of nearby base station sites that can not use the same frequency channel, in view to avoid co-channel interference.

This is an excerpt from the article WFQ from the Wikipedia free encyclopedia. A list of authors is available at Wikipedia.
The article WFQ at en.wikipedia.org was accessed 54 times in the last 30 days. (as of: 08/31/2013)
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Weighted fair queueing - Wikipedia, the free encyclopedia
Weighted fair queueing (WFQ) is a data packet scheduling technique allowing different scheduling priorities to statistically multiplexed data flows. Weighted fair  ...
en.wikipedia.org/wiki/Weighted_fair_queueing
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What is weighted fair queueing (WFQ)? - Definition from WhatIs.com
Weighted fair queueing WFQ is a method of automatically smoothing out the flow of data in packetswitched communication networks by sorting packets to ...
searchnetworking.techtarget.com/definition/weighted-fair-queueing
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Weighted Fair Queuing (WFQ) - McMaster University
4DN4 - WFQ, pg 4. Flow of Packets [text, p539]. ▫. An IP router = a node where IP packets arrive, are segmented into fixed-size cells, queued at the input queues ...
www.ece.mcmaster.ca/faculty/teds/COURSES/731-folder/CLASS-NOTES%20folder/L5a-731-WFQ-slides-(updated)-2pp.pdf
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Weighted Fair Queuing (WFQ) - Cisco Systems
WFQ is one of Cisco's premier queuing techniques. It is a flow-based queuing algorithm that does two things simultaneously: It schedules interactive traffic to the ...
www.cisco.com/en/US/tech/tk543/tk544/tk718/tsd_technology_support_sub-protocol_home.html
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Cisco IOS Quality of Service Solutions Configuration Guide, Release ...
WFQ provides traffic priority management that automatically sorts among individual traffic streams without requiring that you first define access lists. WFQ can ...
www.cisco.com/c/en/us/td/docs/ios/12_2/qos/configuration/guide/fqos_c/qcfwfq.html
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Packet Scheduling: ( ) Weighted Fair Queueing (WFQ) and Virtual ...
Mar 4, 2014 ... Each flow receives a service rate of R/n, where R is channel rate in bps and n is the number of flows with non-empty queue. 2. WFQ and VC ...
www.cs.utexas.edu/users/lam/386p/slides/Packet_Scheduling_algorithms.pdf
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WFQ Implementation - SICS
The WFQ implementation primarily consists of three routines: getSessionIdentity, enqueue and dequeue. The data structures are one FIFO queue per session in ...
www.sics.se/~ianm/WFQ/wfq_descrip/node23.html
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Weighted Fair Queuing - MyNetworkingWiki
Weighted Fair Queuing. From MyNetworkingWiki. QoS. Introduction. One of the big difference between WFQ and other queuing tools is that it classifies packets ...
mynetworkingwiki.com/index.php/Weighted_Fair_Queuing
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WFQ queuing discipline - OpalSoft - Practical IP Network QoS
WFQ queuing discipline belong to the family of Fair Queuing (FQ) algorithms. FQ was proposed by John Nagle in 1987. This queuing discipline was designed to ...
web.opalsoft.net/qos/default.php?p=whyqos-2424
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WFQ definition of WFQ in the Free Online Encyclopedia.
Encyclopedia article about WFQ. Information about WFQ in the Columbia Encyclopedia, Computer Desktop Encyclopedia, computing dictionary.
encyclopedia2.thefreedictionary.com/WFQ
Search results for "WFQ"
Google: approx. 908.000
WFQ in science
[PDF]Weighted Fair Queuing (WFQ) - McMaster University
4DN4 - WFQ, pg 4. Flow of Packets [text, p539]. ▫. An IP router = a node where IP packets arrive, are segmented into fixed-size cells, queued at the input queues ...
Decomposition of a WFQ tag computation architecture - Queen's ...
Queen's University Belfast · Twitter_25W_25H · Facebook_25W_25H ... Decomposition of a WFQ tag computation architecture. Research output: Contribution to ...
An agent-based control mechanism for WFQ in IP networks ... - Pure
Queen's University Belfast · Twitter_25W_25H ... An agent-based control mechanism for WFQ in IP networks. Research output: Contribution to journal › Article.
[PDF]a comparative study of different queuing techniques in voip, video ...
DAFFODIL INTERNATIONAL UNIVERSITY JOURNAL OF SCIENCE AND ... WFQ . The study has been carried out on some issues like: Traffic dropped Traffic ...
[PDF]Enhancing QoS by Using Weighted Fair Queuing ... - IJARCSSE
Enhancing QoS by Using Weighted Fair Queuing Techniques. Mohamed Seidi Ahmed Hmadi. Nims Institute of Engineering and Technology,. NIMS University ...
CCIE University | Which QoS mechanism for VoIP works with ...
Which QoS mechanism for VoIP works with weighted fair queuing (WFQ) and class-based weighted fair queuing (CBWFQ)? A. Header compression. B. FRF.12
Investigating the Effects of Encoder Schemes, WFQ & SAD on VoIP ...
Voice Encoder Schemes, Weighted Fair Queuing (WFQ) and Speech Activity ... Computer Science and Engineering Department, University of Bridgeport, ...
[PDF]An embedded fuzzy expert system for adaptive WFQ ... - ScienceDirect
Jun 11, 2014 ... a UIET, Panjab University, Sector 25, Chandigarh, India b Department of ..... study has decided to use more efficient and fairer WFQ algorithm.
Distributed WFQ Scheduling in Buffered Crossbars (FORTH-ICS)
Distributed WFQ Scheduling in Buffered Crossbar (CICQ) Switches. Nikolaos ... Dept. of Computer Science, University of Crete, Heraklion, Crete, Greece.
[PDF]A Survey of Scheduling Methods - Department of Computer Science ...
The Ohio State University. Weighted Fair Queueing. (WFQ) u Basis of IETF's integrated services u Naive implementation requires O(log(m)), m=# of packets.
Books on the term WFQ
Voice Over IP Fundamentals
2006
CB-WFQ (CB=Class Based) CB-WFQ has all the benefits of WFQ, with the additional functionality of providing granular support for network administrator- defined classes of traffic. CB-WFQ also can run on high-speed interfaces (up to T3).
Cisco Voice Over Frame Relay, ATM, and IP
Steve McQuerry, Kelly McGrew, Stephen Foy, 2001
The fundamental differences between WFQ and CBWFQ (they use the same internal algorithm) are: • For WFQ the weight of the flow is given (derived from IP Precedence) and the BW calculated • For CBWFQ the BW is given, and the resulting ...
IP Quality of Service
Srinivas Vegesna, 2001
WFQ limits its drops to the most active flows, whereas FIFO might drop from any flow. Therefore, WFQ should encourage the most active flows to scale back without affecting the smaller flows. Because the median flow duration in the Internet is ...
Inside Cisco IOS Software Architecture
Russ White, Vijay Bollapragada, Curtis Murphy, 2008
IOS has two implementations of platform-independent WFQ: ' Flow-Based WFQ ° Class-Based CBWFQ Flow-Based WFQ NOTE Flow-Based WFQ is similar to custom queuing in its effect on traffic streams, but rather than defining a static policy ...
Integrating Voice and Data Networks
Scott Keagy, 2000
Information about the latest research and real-world findings for RED can be found at the following URL: www.aciri.org/floyd/red.html Class-Based Weighted Fair Queuing Class-Based Weighted Fair Queuing (CB-WFQ) incorporates Custom ...
Development of Google searches


Blog posts on the term
WFQ
wfq - CCIE Blog
blog.ine.com/tag/wfq/
CB-WFQ misconceptions « ipSpace.net by @ioshints
Reading various documents describing Class-Based Weighted-Fair-Queueing (CB-WFQ) one gets the impression that the following configuration … class-map match-all High match access-group name High ! policy-map WAN class High bandwidth percent 50 ! interface Serial0/1/0 bandwidth 256 service-policy output WAN ! ip access-list extended High permit ip any host 10.0.3.1 permit ip host 10.0.3.1 any … allocates 128 kbps to the traffic to/from IP host 10.0.3.1 and distributes the remaining 128 kbps fairly between conversations in the default class. I am overly familiar with weighted fair queuing (I was developing QoS training for Cisco when WFQ just left the drawing board) and was thus always wondering how they manage to implement that behavior with WFQ structures. A comment made by Petr Lapukhov re-triggered my curiosity and prompted me to do some actual lab tests. The answer is simple: CB-WFQ does not work as advertised. To prove this claim, I’ve started two parallel TTCP sessions: one to IP address 10.0.3.1, the other to IP address 10.0.3.2.
blog.ipspace.net/2009/11/cb-wfq-misconceptions.html
Global Knowledge Training Blog » Quality of Service, Part 10 – Weighted Fair Queuing
Your Source for Technical, Professional, & Leadership Training
blog.globalknowledge.com/technology/unified-communications/quality-of-service-part-10-%E2%80%93-weighted-fair-queuing/
Class Based Weighted Fair Queuing for better Traffic Management | ManageEngine Blogs
Jul 18 POSTED BY Praveen Kumar V | NetFlow Analyzer.
blogs.manageengine.com/product-blog/netflowanalyzer/2011/07/18/class-based-weighted-fair-queuing-for-better-traffic-management.html
QoS: Class-based Weighted Fair Queuing | Network World
www.networkworld.com/article/2234350/cisco-subnet/qos--class-based-weighted-fair-queuing.html
Weighted Fair Queue (WFQ) | Tom G CCIE Blog
Weight Fair Queue configuration options To enable R1(config)#int s0/0 R1(config-if)#fair-queue Configure the number of queues and reserved queues (for RSVP) R1(config)#int s0/0 R1(config-if)#fair-queue 30 256 20 The above configures a max of 256 dynamic queues each with a capacity of 30 packets along with 20 reserved queues for RSVP. WFQ formula WFQ for each packet…
ccie4all.wordpress.com/2012/07/22/weighted-fair-queue-wfq/
WFQ - Weighted Fair Queuing
Weighted Fair Queuing (WFQ) - A flow-based queuing algorithm used in Quality of Service (QoS) network applications that schedules low-volume traffic first, while letting high-volume traffic share the remaining bandwidth. This is handled by assigning a weight to each flow, where lower weights are the first to be serviced.
www.birds-eye.net/definition/acronym/?id=1152369097
Class-Based Weighted Fair Queuing (CBWFQ) | CCIE Blog | iPexpert
Class-Based Weighted Fair Queuing (CBWFQ) April 25, 2012 by ipexpert. The following is an excerpt from the upcoming IPexpert book - IPv4/IPv6 QoS Operation and Troubleshooting In the previous section, we discussed how WFQ gives certain types of traffic preferential treatment when congestion occurs on a slow-speed link. In that section, we reviewed how WFQ does this by automatically detecting flows and preventing any one conversation from starving out others on a link.
blog.ipexpert.com/class-based-weighted-fair-queuing-cbwfq/
ccieme | Queuing: FIFO, WFQ, CBWFQ, LLQ + Global Synchronisation
I have already covered some of the QoS basics from CCNA Voice, however the Chris Bryant Study Guide dives deeper into the actual configuration of each queuing method. It is no wonder so many people just use AutoQoS instead of manually creating these queues. :) First In First Out (FIFO) FIFO is just what it…
ccieme.wordpress.com/2013/05/26/queuing-fifo-wfq-cbwfq-llq-global-synchronisation/
Weighted Fair Queuing – WFQ | OKS's CCIE Voice Blog
ccievoice.ksiazek.be/?p=395
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