[1] Examples include routers,[2] routing switches, integrated access devices (IADs), multiplexers, and a variety of metropolitan area network (MAN) and wide area network (WAN) access devices.
[3] In general, edge devices are normally routers that provide authenticated access (most commonly PPPoA and PPPoE) to faster, more efficient backbone and core networks.
Consequently, core networks are often designed with switches that use routing protocols such as Open Shortest Path First (OSPF) or Multiprotocol Label Switching (MPLS) for reliability and scalability, allowing edge routers to have redundant links to the core network.
Links between core networks are different—for example, Border Gateway Protocol (BGP) routers are often used for peering exchanges.
An edge switch for a WAN may be a multiservice unit, meaning that it supports a wide variety of communication technologies, including Integrated Services Digital Network (ISDN), T1 circuits, Frame Relay, and ATM.