Fixed switches are often deployed at the aggregation layer and access layer. Unlike modular switches, fixed switches have a fixed number of ports and cannot add LPUs to expand the number of ports. When the network expands continuously, the number of ports provided by a single fixed switch may be insufficient to meet network requirements. Stack technology uses physical member ports and stack cables to combine multiple stacking-capable switches into one logical switch. You can set up a stack to improve network scalability and device reliability.