Telecommunications and exchange between information technology systems — Requirements for local and metropolitan area networks — Part 3: Standard for Ethernet — Amendment 2: Physical layer and management parameters for power over Ethernet over 4 pairs
信息技术系统之间的电信和交换.局域网和城域网的要求.第3部分:以太网标准.修改件2:4对以上以太网电源的物理层和管理参数