An edge device primarily enables a local user to connect and transfer data to a network, which is external or is non-propriety to the organization/user. An edge device serves as the entry point into a service provider, carrier or an enterprise primary network. They also provide network translation between networks that use different protocols. For example, an edge device will translate and transfer packets and cells in between an Ethernet and ATM network.

Network devices that have immediate or direct connection to the Internet or an external non-propriety network are edge devices. Edge switches, routers, multiplexers and other WAN devices are common types of edge devices.