| # OpenThread on Windows # |
| |
| These components are the building blocks to get OpenThread integrated into the Windows |
| networking stack and provide an interface for applications to control it. |
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| ## Architecture ## |
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| [ndis]: https://msdn.microsoft.com/en-us/windows/hardware/drivers/network/ndis-drivers |
| [lwf]: https://msdn.microsoft.com/en-us/windows/hardware/drivers/network/ndis-filter-drivers |
| [miniport]: https://msdn.microsoft.com/en-us/windows/hardware/drivers/network/ndis-miniport-drivers2 |
| [ioctl]: https://msdn.microsoft.com/en-us/library/windows/desktop/aa363219(v=vs.85).aspx |
| [oid]: https://msdn.microsoft.com/en-us/library/windows/hardware/ff566707(v=vs.85).aspx |
| [nbl]: https://msdn.microsoft.com/en-us/windows/hardware/drivers/network/net-buffer-architecture |
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| This design allows for support of both simple radio devices and devices running the complete |
| OpenThread stack. |
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| ### otApi.dll ### |
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| This is the dynamic libray for applications to control the OpenThread stack from user mode. It |
| exposes all the control path APIs from `openthread.h`. It interfaces with the driver by the use |
| of [IOCTL][ioctl]s. The IOCTLs allow otApi.dll to serialize and send commands, and poll for notifications, |
| which can then be returned back to the client. |
| |
| ### otLwf.sys ### |
| |
| This is where most of the real logic lives. `otLwf.sys` is an [NDIS][ndis] Light Weight Filter ([LWF][lwf]) driver. |
| It plugs into the networking stack, binding to a protocol driver (TCPIP) at the top, and an NDIS [Miniport][miniport] |
| at the bottom. It's job is to take IPv6 packets from TCPIP and pass the necessary data down to the Miniport |
| in order to send the packets out over the network. |
| |
| `otLwf.sys` supports operating in two modes: Full Stack and Tunnel. Full Stack mode is where OpenThread is |
| running on the host (in Windows) and a simple radio device is connected externally. Tunnel mode is where |
| OpenThread is running on the external device and Windows is merely a pass through for commands and packets. |
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| In both cases, `otLwf.sys` uses the Spinel command interface for interacting with the connected device. When operating |
| in Full Stack mode, `otLwf.sys` uses only the low level PHY/MAC commands. In Tunnel mode, it uses the higher layer |
| Spinel commands and lets the device manage the actual Thread stack. |
| |
| ### ottmp.sys ### |
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| This is the component responsible passing the Spinel commands from `otLwf.sys` down to the device. It is responsible |
| for abstracting the actual mechanism (USB, Serial, SPI) used for communicating with the device. It handles the device |
| arrival/removal and the encoding/decoding of data when communicating with it. The current implementation only handles |
| Serial devices. |
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| ### Device ### |
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| Windows supports OpenThread devices that implement the Spinel protocol. It supports devices that support either the raw |
| link-layer PHY/MAC commands and devices that support the Thread commands (and devices that support both). By default, |
| Windows will operate in Full Stack mode, only sending raw link-layer commands. |
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