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The mac80211 stack
The mac80211 subsystem (formerly known as the Devicescape stack) provides comprehensive support for wireless network adapters under Linux. A number of adapters are supported in current kernels, but support for many - especially those requiring software MAC support - is spotty. Integration of mac80211 will rationalize Linux wireless support and clear the way for the merging of a number of new drivers.
Forecast: this code has been merged for 2.6.22 and the first mac80211 driver was merged in 2.6.23. Additional drivers have been merged since, including the crucial ath5k (Atheros) driver for 2.6.25. Work has continued since then, with important features (such as the regulatory framework) being added over time.
For more information:
- The 2006 wireless networking summit (April, 2006)
- Regulating wireless devices (August, 2008)
Channels
The "channels" concept was first presented by Van Jacobson at linux.conf.au 2006. In short, channels promise greatly improved networking performance, especially on large servers, through a combination of cache-friendly data structures and pushing all processing as close to the end points as possible - perhaps even into user space.
Forecast: Channels are an idea which works very well in isolated laboratory setups, but which proves difficult to implement in a real-world environment where other functionality, such as firewalls and policy routing, must also be provided. So, while there has been occasional work on channel-oriented patches, nothing is close to ready for the mainline. There is unlikely to be a production-ready channels patch the near future.
For more information:
- Van Jacobson's network channels (January, 2006)
- Implementing network channels (May, 2006)
- Reconsidering network channels (July, 2006)
- The grand unified flow cache (August, 2006)
- The return of network channels (December, 2007)
Controller area networks
The Controller Area Network (CAN) specification describes networks operated in small, possibly hostile environments - in cars, for example. While there have been a number of CAN implementations for Linux, none have gone into the mainline, and most do not actually make use of the Linux networking infrastructure. The PF_CAN code, created by developers at Volkswagen, is an attempt to get proper CAN support into the mainline.
Forecast: the PF_CAN developers have had a few difficulties working with the kernel development process, but most of those problems appear to have been resolved. As a result, PF_CAN was merged for 2.6.25.
For more information:
- PF_CAN (October, 2007)
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