Definitions for "Collapsed Backbone"
A network topology that uses a multiport device, such as a switch or router, to carry traffic between network segments or subnets is a collapsed backbone. This is in contrast to a standard backbone which, in the case of Ethernet, consists of a single common bus cable to which nodes and subnets are connected.
Nondistributed backbone in which all network segments are interconnected by way of an internetworking device. A collapsed backbone might be a virtual network segment existing in a device such as a hub, a router, or a switch.