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:
“In religion,
What damned error but some sober brow
Will bless it, and approve it with a text,
Hiding the grossness with fair ornament?”
—William Shakespeare (1564–1616)
“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)