Switches and bridges are similar, but switches have higher aggregate bandwidth and lower latency. Networks based on switches offer dramatic performance improvements. Shared and dedicated LAN switches segment LANs as do routers and bridges, thus increasing shared bandwidth. A LAN switched network with dedicated connections to end users' workstations provides high bandwidth and can support time-sensitive, multimedia applications. LAN switching is inexpensive and presents few migration obstacles.
Switched networks can form logical LANs overlaying physical LANs.
These virtual LANs dramatically change the role of routers in the campus. Today most traffic passes through routers, resulting in congestion and latency. No mechanism ensures that traffic has priority in the network, thus limiting the deployment of new multimedia applications. Bridging between workgroup switches and the backbone induces latency. Data loss can occur due to the lack of large buffers and standard flow-control mechanisms if switches are used in the backbone.