The present document addresses the requirements of network and service providers of Asynchronous Transfer Mode
(ATM) cross connected networks for managing the fault alarms associated with the Virtual Path (VP) connections and
Virtual Channel (VC) connections (generally denoted as VP/VC connections in the present document), which span
several administrative ATM domains. These requirements are satisfied by the use of a standardized interface (the "Xinterface")
between Operation Systems (OSs) belonging to different Network Operators (PNOs).
Readers of the present document should be made aware that the abbreviation PNO is taken to mean Providing Network
Operator. In the previous version of the present document (and related documents), PNO was defined as Public
Network Operator. The change in definition has been provided to reflect the change in market conditions for provision
of interconnected telecommunications services. However, it is considered necessary to retain the abbreviation PNO
because it is found in many of the managed object definitions used to specify the X-interface. It would be
disadvantageous to introduce major changes in these managed object definitions, which serve purely technical purposes
for management of interconnections only.
The present document should be used in conjunction with EN 300 820-1 [1] and EN 300 820-3 [14]. The present
document describes the X-interface VP / VC alarm management area covering the following aspects:
the Management Services (MS) and functions needed that provide the necessary alarm messages for faults
detected and related recovery procedures within ATM VP or VC Connections which span several
administrative domains;
the management information crossing the X-interface. This management information specification uses the
Guidelines for the Definition of Managed Objects (GDMO) formalism, described in
ITU-T Recommendation X.722 [2].