A stackable hub is a hub designed to be connected and stacked or positioned on top of another hub, forming an expanding stack. Since a hub is basically a concentrator of device connections, a set of stackable hubs is just a bigger concentrator. The stackable approach allows equipment to be easily and economically expanded as a grows in size. The stacking feature also reduces clutter.
Typically, devices with network interface cards (NIC) are connected to each hub with shielded twisted pair (STP) or unshielded twisted pair (UTP) cable. The set of stackable hubs is interconnected with a very short "cascading" cable in the rear of the stack. A special port, such as an Ethernet Attachment Unit Interface (AUI) port, may be provided to connect the set of stackable hubs to a backbone cable that connects to other sets of stackable hubs or other network devices.
Typical stackable hub options include:
- The ability to mix hubs, router, and other devices in the same stack
- Fault tolerance so that if one hub fails, the other hubs in the stack can continue to operate
- port redundancy so that if one port fails, a backup port can be automatically substituted
- Hardware and software to let you manage the stackable hubs using the Simple Network Management Protocol (SNMP)