The VSP 8400 Ethernet Switch provides four front-panel slots that support the flexible deployment of high-density VSP 8400 Series Ethernet Switch Modules. By default, the VSP 8400 is a "zero port" system, with a chassis that integrates the switching fabric and all associated control and management electronics. Ethernet interfaces are delivered by the addition of one or more field-replaceable and hot-swappable Ethernet Switch Modules (ESMs). The 8424GS is a 24-port Gigabit Ethernet SFP ESM.