Huawei S5720-28P-SI-AC delivers high performance of switching capacity and powerful layer 3 routing capabilities, such as OSFP/OSPFv3, BGP/BGP4+, ISIS/ISISv6, and provides voice, video and data services, helping enterprises build an integrated full service network with high availability and low latency. The S5720-28P-SI complies with IEEE 802.3af and 802.3at (PoE+), each port provides a maximum 30W of power, complying with IEEE 802.3at. The PoE+ function increases the maximum power of each port and implements intelligent power management for high-power consumption applications. The S5720-28P-SI-AC supports intelligent stacking (iStack). Multiple S5720-SI can be connected with stack cables to set up a stack, which functions as a virtual switch. A stack consists of a master switch, a backup switch, and several slave switches. The backup switch takes over services when the master switch fails, reducing service interruption time. Stacks support intelligent upgrade so that users do not need to change the software version of a switch when adding it to a stack. The iStack function allows users to connect multiple switches with stack cables to expand system capacity.