Understand what NCSI functions are in one article

What are the popular NCSI features in the server space?

The era of artificial intelligence and big data has arrived. In the face of increasing data processing tasks, server CPU pressure is increasing day by day. If the server board management controller (BMC) can manage the network card out of band and process data through NCSI, it can greatly reduce the pressure on the CPU, and is popular with server manufacturers. So, what exactly is the NCSI here?

NCSI (Network Controller Sideband Interface) is an industry standard defined by the International Standardization Organization DMTF (Distributed Management Task Force) for supporting side band interface network controllers for server out of band management. In simple terms, NCSI is the protocol defined for communication between the management controller (BMC) of the master controller and the network card.

Initially, BMC had a dedicated Ethernet port for remote management of Ethernet connections. Later, Ethernet manufacturers began using proprietary sideband interfaces, a mechanism that allows BMCs to share Ethernet ports with the operating system. This interface is typically based on the I2C/SMBus interface, but has a dedicated protocol. Subsequently, DMTF created an industry standard sideband interface, the NCSI interface, which is faster in transmission speed than SMBus.

However, the implementation of the NCSI function depends on the firmware of the network card itself. If the network card itself supports the NCSI function, it can remotely access the BMC through the IP address of the NCSI network interface. In the process of device operation, the implementation of traditional NCSI functions requires the BMC chip to connect to the network card chip on the server motherboard through the NCSI signal bus, and then transmit or receive the monitoring information of the server through the network interface sharing the server network card chip, thereby releasing CPU resources. However, this method not only requires the standard PCI-E network card to support NCSI functions, but also requires additional cables to connect to the NCSI function interface of the network card on the motherboard, making wiring cumbersome and increasing costs.