Fujitsu IRMC S2/S3 manual Channel concept under Ipmi, BMC and SOL

IPMI - technical background

Figure 5: BMC and SOL

The SOL character data is then exchanged between the BMC of the managed system and the remote workstation as SOL messages. The SOL messages are encapsulated in RMCP+ data packets and transferred in UDP datagrams over an Ethernet LAN connection using IPv4 (Internet Protocol Version 4). The RMCP+ protocol is based on the RMCP protocol, but includes extensions for encryption, authentication, etc.

Serial over LAN permits “headless” management by console redirection by both the BIOS and the operating system of the managed server. High-cost concentrator solutions are not required.

Channel concept under IPMI

‘Channels’ provide the mechanisms with which IPMI messages are routed to the BMC via various connection carriers. Up to nine channels can be supported. The system interface and the primary IPMB are fixed. The other seven channels are available for the implementation.

Channels can be either ‘session based’ or ‘sessionless’. The ‘session’ concept has two meanings: It is either a concept for user authentication (see the section "User identifications" on page 29) or a concept for routing multiple IPMI message streams via a single channel.

Examples of ‘session based’ channels are LAN channels or serial / modem channels. Examples of ‘sessionless’ channels are the system interface and the IPMB.

28 iRMC S2/S3