choke - choose and keep scheduler
tc qdisc ... choke limit packets min packets max
packets avpkt bytes burst packets [ ecn ] [ bandwidth
rate ] probability chance
CHOKe (CHOose and Keep for responsive flows, CHOose and Kill for unresponsive
flows) is a classless qdisc designed to both identify and penalize flows that
monopolize the queue. CHOKe is a variation of RED, and the configuration is
similar to RED.
Once the queue hits a certain average length, a random packet is drawn from the
queue. If both the to-be-queued and the drawn packet belong to the same flow,
both packets are dropped. Otherwise, if the queue length is still below the
maximum length, the new packet has a configurable chance of being marked
(which may mean dropped). If the queue length exceeds max, the new
packet will always be marked (or dropped). If the queue length exceeds
limit, the new packet is always dropped.
The marking probability computation is the same as used by the RED
The parameters are the same as for RED, except that RED uses bytes whereas choke
counts packets. See tc-red(8) for a description.
sched_choke was contributed by Stephen Hemminger.
- R. Pan, B. Prabhakar, and K. Psounis, "CHOKe, A Stateless Active
Queue Management Scheme for Approximating Fair Bandwidth Allocation",
IEEE INFOCOM, 2000.
- A. Tang, J. Wang, S. Low, "Understanding CHOKe: Throughput and
Spatial Characteristics", IEEE/ACM Transactions on Networking, 2004