In a
communication network
A telecommunications network is a group of Node (networking), nodes interconnected by telecommunications links that are used to exchange messages between the nodes. The links may use a variety of technologies based on the methodologies of circuit ...
, sometimes a
max-min fairness
In communication networks, multiplexing and the division of scarce resources, max-min fairness is said to be achieved by an allocation if and only if the allocation is feasible and an attempt to increase the allocation of any participant necessari ...
of the network is desired, usually opposed to the basic
first-come first-served
Queueing theory is the mathematical study of waiting lines, or queues. A queueing model is constructed so that queue lengths and waiting time can be predicted. Queueing theory is generally considered a branch of operations research because the ...
policy. With max-min fairness, data flow between any two nodes is maximized, but only at the cost of ''more or equally expensive'' data flows. To put it another way, in case of
network congestion
Network congestion in data networking and queueing theory is the reduced quality of service that occurs when a network node or link is carrying more data than it can handle. Typical effects include queueing delay, packet loss or the blocking of ...
any data flow is only impacted by smaller or equal flows.
In such context, a bottleneck link for a given data flow is a link that is fully utilized (is ''saturated'') and of all the flows sharing this link, the given data flow achieves maximum data rate network-wide.
Jean-Yves Le Boudec (EPFL Lausanne) "Rate adaptation, Congestion Control and Fairness: A Tutorial" Nov 2005
/ref> Note that this definition is substantially different from a common meaning of a ''bottleneck''. Also note, that this definition does not forbid a single link to be a bottleneck for multiple flows.
A data rate allocation is max-min fair if and only if a data flow between any two nodes has at least one bottleneck link.
See also
* Fairness measure Fairness measures or metrics are used in network engineering to determine whether users or applications are receiving a fair share of system resources. There are several mathematical and conceptual definitions of fairness.
TCP fairness
Congestion ...
* Max-min fairness
In communication networks, multiplexing and the division of scarce resources, max-min fairness is said to be achieved by an allocation if and only if the allocation is feasible and an attempt to increase the allocation of any participant necessari ...
References
{{network-stub
Network performance