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.
An NMDS implementation may contain one ISDN-BA port and/or a limited number of PSTN ports up to a maximum
of 10. Typically one or two PSTN ports would be supported.
The objective of the present document is to provide conformance test purposes giving a high probability of
inter-operability of a Network Termination Node (NTN) and a Local Exchange (LE) on the DLL from different
manufacturers over the NMDS interface. The present document covers only the procedures described in
EN 301 141-1 [1].
ISO/IEC 9646-1 [11] is used as the basis for the methodology of conformance testing.
EN 301 141-1 [1] defines the NMDS layer 2 functions:
For the ISDN-BA layer 2 functions, point-to-point (i.e. TEI 0) or point-to-multipoint procedures may be
supported using the full ISDN TEI assignment procedures as currently defined. These include TEI assignment
and removal procedures. However, there is an NMDS-specific constrain (...abbreviated)