Blue (queue Management Algorithm) - Stochastic Fair Blue

Stochastic Fair Blue

The main flaw of Blue, which it shares with most single-queue queueing disciplines, is that it doesn't distinguish between flows, and treats all flows as a single aggregate. Therefore, a single aggressive flow can push out of the queue packets belonging to other, better behaved, flows.

Stochastic Fair Blue (SFB) is a stochastically fair variant of Blue which hashes flows and maintains a different mark/drop probability for each hash value. Assuming no hash collisions, SFB is able to provide a fair share of buffer space for every flow. In the presence of hash collisions, SFB is only stochastically fair.

Unlike other stochastically fair queuing disciplines, such as SFQ, SFB can be implemented using a Bloom filter rather than a hash table, which dramatically reduces its storage requirements when the number of flows is large.

When a flow's drop/mark probability reaches 1, the flow has been shown to not react to congestion indications from the network. Such an inelastic flow is put in a "penalty box", and rate-limited.

Read more about this topic:  Blue (queue Management Algorithm)

Famous quotes containing the words fair and/or blue:

    I conjure thee, and all the oaths which I
    And thou have sworn to seal joint constancy,
    Here I unswear, and overswear them thus,
    Thou shalt not love by ways so dangerous.
    Temper, O fair Love, love’s impetuous rage,
    Be my true Mistress still, not my feign’d Page;
    I’ll go, and, by thy kind leave, leave behind
    Thee, only worthy to nurse in my mind
    Thirst to come back;
    John Donne (1572–1631)

    The Reverend Samuel Peters ... exaggerated the Blue Laws, but they did include “Capital Lawes” providing a death penalty for any child over sixteen who was found guilty of cursing or striking his natural parents; a death penalty for an incorrigible son; a law forbidding smoking except in a room in a private house; another law declaring smoking illegal except on a journey five miles away from home,...
    —Administration for the State of Con, U.S. public relief program (1935-1943)