The present document defines the stage one of the MessageWaiting Indication (MWI) supplementary service for the
pan-European Integrated Services Digital Network (ISDN) as provided by European public network operators. Stage
one is an overall service description from the users point of view (see ITU-T Recommendation I.130 [4] and ITU-T
Recommendation I.221 [6]), but does not deal with the details of the human interface itself.
The present document defines the interworking requirements of private ISDNs with the public ISDN.
Interactions with supplementary services not listed in clause 7 are outside the scope of the present document.
The MWI supplementary service is provided independently of a call and is therefore applicable to a number of
telecommunication services.
Charging principles are outside the scope of the present document.
The MWI supplementary service enables the network, upon the request of a controlling user to indicate to the receiving
user, that there is at least one message waiting.
NOTE: The MWI supplementary service is typically used between a mailbox service provider (controlling user)
and a user (receiving user) of the mailbox service provided.
The present document is applicable to the stage two and stage three standards for the ISDN MWI supplementary
service. The terms "stage two" and "stage three" are also defined in ITU-T Recommendation I.130 [4] and ITU-T
Recommendation I.221 [6]. Where the text indicates the status of a requirement (i.e., as strict command or prohibition,
as authorization leaving freedom, or as a capability or possibility), this shall be reflected in the text of the relevant stage
two and stage three standards.
Furthermore, conformance to the present document is met by conforming to the stage three standard with the field of
application appropriate to the equipment being implemented. Therefore, no method of testing is provided for the present
document.