An Integrated Access Device (IAD) is an access device that can simultaneously deliver traditional PSTN voice services, packet voice services, and data services (via LAN ports) over a single WAN link. It aggregates multiple channels of information including voice and data across a single shared access link to a carrier or service provider PoP (Point of Presence). The access link may be a T1 line, a DSL connection, a cable (CATV) network, a broadband wireless link, or a metro-Ethernet connection.

An IAD is typically installed at the customer premises. Sometimes, an IAD is installed by the service provider if a customer wish to do so. This allows the service provider to control the features of the access link and manage its operation during use.

The definition of the IAD has been evolving from a simple device that provides access at line rates of T1 and E1, to high port count, feature dense, higher-layer devices such as ATM edge concentrators and universal multiplexers. As the demand for immediate access to information has increased, so has the demand for increased bandwidth and varied flexible services. The concept of the IAD has grown with those demands, and today meets the requirements of both the end customer and the service provider for integrated WAN access.

There are basically three types of IAD devices:

• The traditional time-division multiplexer plus routing capabilities in the box: In addition offering V.35 interfaces to routers, it may have Ethernet ports and PBX links.
• A frame relay access device (FRAD) with voice capability.
• ATM-based IADs: it concentrate voice, video and data, in some cases eliminating the PBX and router.

IAD: Integrated Access Device

Related Terms: ATM, Frame Relay, Multiplexer, PSTN, Access network, edge network