This part specifies the technical requirements for space switches, including functional indicators, communication protocols, communication interfaces, environmental requirements, etc. In this section, Ethernet switches refer to LAN switches with Ethernet interfaces. All unspecified switches in this article refer specifically to Ethernet switches. This section applies to Ethernet switches with network management functions that work on the second data link layer in ISO's OSI 7-layer reference model. This section does not apply to Ethernet switches working at layer 3 or higher without network management functions.