Definition: edge device

(1) Any server or other networking device that is located closer to the client machines rather than being in the backbone of the network. For example, a cache server is an edge device that sits inside the firewall and holds frequently requested pages. See cache server and edge router.

(2) A network device used to convert LAN frames (Ethernet, etc.) to ATM cells and vice versa. It is typically a switching device with one ATM port and multiple LAN ports. To legacy stations, ports on an edge device look like a router port.

Under MPOA (Multiprotocol Over ATM), the edge device queries a route server for address resolution when the destination station is outside of its attached LANs. It sets up a switched virtual circuit (SVC) in the ATM network, maps LAN frames into ATM frames and forwards the traffic to the ATM backbone. Thus, the edge device performs functions usually associated with a router and becomes a major component in a LAN environment with an ATM backbone.

Edge Device

This diagram shows how an edge device interfaces into an ATM network. It converts ATM cells into LAN frames and vice versa. This example depicts an Ethernet edge device, but edge devices exist for Token Ring and FDDI LANs as well.