Digital Data System (DDS) - T1 Data Multiplexer (T1DM) Requirements
Document Number TA-TSY-000278
Issue Number 01
Issue Date Nov 1985
ABSTRACT: The Digital Data System (DDS) employs T1 carrier facilities for transmission within and between digital serving areas. To obtain
efficient utilization of these 1.544 Mb/s facilities, the data from many customers' loops are multiplexed into a T1 facility in three
stages. The first stage multiplexes the customer's loop signal into a 64-kb/s DS0A signal. The second stage multiplexes DS0A signals
to the DS0B format. The third stage, which multiplexes 23 DS0 signals to the 1.544-Mb/s DS1 line rate, is by convention termed a T1
Data Multiplexer (T1DM).
This Technical Advisory (TA) provides the preliminary view of Telcordia on generic requirements for this multiplexing process along
with specific requirements for T1DM interfaces and maintenance. The objective of the document is to identify generic requirements so
that a useful product is available for use within the Digital Data System (DDS) network as well as for new applications outside of
existing DDS facilities. The description of the T1DM is given in terms of requirements and features. Requirements are those
characteristics that the basic T1DM must have. Features are those additional characteristics that may be provided as part of the basic
T1DM or on an optional basis.