-.. BSD LICENSE
- Copyright(c) 2017 Intel Corporation. All rights reserved.
- All rights reserved.
-
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions
- are met:
-
- * Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
- * Redistributions in binary form must reproduce the above copyright
- notice, this list of conditions and the following disclaimer in
- the documentation and/or other materials provided with the
- distribution.
- * Neither the name of Intel Corporation nor the names of its
- contributors may be used to endorse or promote products derived
- from this software without specific prior written permission.
-
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
+.. SPDX-License-Identifier: BSD-3-Clause
+ Copyright(c) 2017 Intel Corporation.
Traffic Management API
======================
shared (by multiple nodes) shapers
* Congestion management for hierarchy leaf nodes: algorithms of tail drop, head
drop, WRED, private (per node) and shared (by multiple nodes) WRED contexts
+ and PIE.
* Packet marking: IEEE 802.1q (VLAN DEI), IETF RFC 3168 (IPv4/IPv6 ECN for TCP
and SCTP), IETF RFC 2597 (IPv4 / IPv6 DSCP)
At the TM level, users can get high level idea with the help of various
parameters such as maximum number of nodes, maximum number of hierarchical
levels, maximum number of shapers, maximum number of private shapers, type of
-scheduling algorithm (Strict Priority, Weighted Fair Queueing , etc.), etc.,
+scheduling algorithm (Strict Priority, Weighted Fair Queuing , etc.), etc.,
supported by the implementation.
Likewise, users can query the capability of the TM at the hierarchical level to
Congestion management is used to control the admission of packets into a packet
queue or group of packet queues on congestion. The congestion management
algorithms that are supported are: Tail Drop, Head Drop and Weighted Random
-Early Detection (WRED). They are made available for every leaf node in the
-hierarchy, subject to the specific implementation supporting them.
+Early Detection (WRED), Proportional Integral Controller Enhanced (PIE).
+They are made available for every leaf node in the hierarchy, subject to
+the specific implementation supporting them.
On request of writing a new packet into the current queue while the queue is
full, the Tail Drop algorithm drops the new packet while leaving the queue
unmodified, as opposed to the Head Drop* algorithm, which drops the packet
definition of WRED profiles. Any WRED profile can be used by one or several
WRED contexts (either private or shared).
+The Proportional Integral Controller Enhanced (PIE) algorithm works by proactively
+dropping packets randomly. Calculated drop probability is updated periodically,
+based on latency measured and desired and whether the queuing latency is currently
+trending up or down. Queuing latency can be obtained using direct measurement or
+on estimations calculated from the queue length and dequeue rate. The random drop
+is triggered by a packet's arrival before enqueuing into a queue.
+
Packet Marking
--------------
git.droids-corp.org / dpdk.git / blobdiff