PDN) Defined in the Telecommunications Act 2001 as "a data network used, or intended for use, in whole or in part, by the public". The Act defines a Fixed PDN as (a) means a PDN, or that part of a PDN, that connects an end-user's building (or, in the case of commercial buildings, the building distribution frames) to a data switch or equivalent facility; and (b) includes the data switch or equivalent facility and that part of the overall telecommunications link within the building that connects to the end-user's equipment.

Network operated by common carriers or telecommunications administrations for the provision of packet switched circuits to the public.