scope:

The present document defines requirements to support the Narrowband Multi-service Delivery System (NMDS) which provides interfaces connected via a Network Termination Node (NTN) to a Local Exchange (LE), in order to support existing PSTN and ISDN-BA services over an existing ISDN-Basic Access digital subscriber line (DSL). The present document contains the Test Suite Structure (TSS) and Test Purposes (TPs) for the data link layer (NTN side only) of an NMDS interface. The LE layer 2 state machine is as per ETS 300 402-2 [5]. The present document also contains requirements relating to the functionality of a (new) Network Termination Node (NTN) for supporting both Public Switched Telephone Network (PSTN) access and Integrated Services Digital Network - Basic Access (ISDN-BA) S/T reference point interfaces over a single (digital section) transmission system as used for an existing ISDN-BA. The NTN encompasses NT2-like (noted NT2*) functionality, physical PSTN user port(s), and PSTN protocol functionality.