Abtin Keshavarzian
2ce3d3bf02
This commit implements delay-aware queue management. When enabled the device will monitor time-in-queue of messages in the direct tx queue and if it is lager than specified thresholds it updates ECN flag (if message indicates it is ECN-capable) and/or drop the message. This mechanism is applied to IPv6 messages on the first device that sends the message into Thread mesh and also on intermediate routers that are forwarding the message (e.g., as a "mesh lowpan fragment" frame). On an intermediate router when forwarding the fragments of a message, if any fragment is dropped by the queue management policy, all subsequent fragments will also be dropped. In particular, this commit contains the following: - Adds `DecompressEcn()` and `MarkCompressedEcn()` in `Lowpan` class to decompress or update the ECN field in a compressed IPHC header (unit test `test_lowpan` is also updated to test the new methods). - Adds `UpdateEcnOrDrop()` which implements the main queue management logic. This method is used when preparing next direct tx message. It decides whether to keep the message as is, update ECN on it or drop it. - Updates `EvictMessage()` to first apply the queue management rule to see if any message can be dropped before using the eviction logic based on message priority. - Updates and reuses the `FragmentPriorityList` to track whether queue management dropped any of the fragments of same message so to also drop any subsequent ones. - Updates `LogMessage()` to log when a message is dropped by queue-management or when ECN is marked on a message.
What is OpenThread?
OpenThread released by Google is... 
...an open-source implementation of the Thread networking protocol. Google Nest has released OpenThread to make the technology used in Nest products more broadly available to developers to accelerate the development of products for the connected home.
...OS and platform agnostic, with a narrow platform abstraction layer and a small memory footprint, making it highly portable. It supports both system-on-chip (SoC) and network co-processor (NCP) designs.
...a Thread Certified Component, implementing all features defined in the Thread 1.2 specification, including all Thread networking layers (IPv6, 6LoWPAN, IEEE 802.15.4 with MAC security, Mesh Link Establishment, Mesh Routing) and device roles, as well as Border Router support.
More information about Thread can be found at threadgroup.org. Thread is a registered trademark of the Thread Group, Inc.
Who supports OpenThread?
Getting started
All end-user documentation and guides are located at openthread.io. If you're looking to do things like...
- Learn more about OpenThread features and enhancements
- Use OpenThread in your products
- Learn how to build and configure a Thread network
- Port OpenThread to a new platform
- Build an application on top of OpenThread
- Certify a product using OpenThread
...then openthread.io is the place for you.
Note: For users in China, end-user documentation is available at openthread.google.cn.
If you're interested in contributing to OpenThread, read on.
Contributing
We would love for you to contribute to OpenThread and help make it even better than it is today! See our Contributing Guidelines for more information.
Contributors are required to abide by our Code of Conduct and Coding Conventions and Style Guide.
Versioning
OpenThread follows the Semantic Versioning guidelines for release cycle transparency and to maintain backwards compatibility. OpenThread's versioning is independent of the Thread protocol specification version but will clearly indicate which version of the specification it currently supports.
License
OpenThread is released under the BSD 3-Clause license. See the LICENSE file for more information.
Please only use the OpenThread name and marks when accurately referencing this software distribution. Do not use the marks in a way that suggests you are endorsed by or otherwise affiliated with Nest, Google, or The Thread Group.
Need help?
OpenThread support is available on GitHub:
- Bugs and feature requests — submit to the Issue Tracker
- Community Discussion - ask questions, share ideas, and engage with other community members