著名的SIP协议栈，为GNU开源项目。通过其提供的API接口，可以轻易开发出基于SIP协议栈的VOIP应用程序。-famous SIP protocol stack for the GNU open source projects. Through its interface with the API, can easily develop SIP-based VoIP protocol stack applications.

NRF51822的蓝牙协议栈,直接烧录。s110_nrf51822_6.0.0_softdevice.hex-NRF51822 Bluetooth protocol stack, burn directly. s110 nrf51822 _6.0.0_softdevice.hex