An access media gateway (AMG) serves as the bridge between a circuit-based voice switch and a packet-based IP or ATM access network. An AMG takes care of the PSTN-to-packet-network transition at the local-loop level and is connected to the local exchange or an access node. It has Class 5 switch interfaces and supports VoIP and/or VoATM.

Included in the AMG segment are inverse AMGs, which make the transition from the packet-access domain — DSL, cable hybrid fiber-coax, power line and local multipoint distribution service — to a PSTN Class 5 local exchange via Generic Requirement (GR)-303, V5.x interface and Primary Rate Interface (PRI) (Q.931) V5.2 access node (AN), and GR-303 remote digital terminal (RDT).