Nortel Meridian 1 Administration And Maintenance page 193

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Chapter 5 — ISDN BRI line and packet data implementation
Types of ISDN BRI terminals
ISDN BRI terminals are divided into four categories based on layer 3 and
layer 2 initialization procedures:
— initializing terminal with dynamic end-point identification
— initializing terminal with static end-point identification
— non-initializing terminal with dynamic TEI assignment
— non-initializing terminal with static TEI assignment
Initializing terminal with dynamic end-point identification
Each initializing terminal has an identification number called a Service
Profile ID (SPID) that is entered into the terminal by the user when the
terminal is installed. This number is usually the directory number with one or
two alphanumeric characters appended to it, although it can be any numeric
or alphanumeric (depending on the type of terminal) number up to nine digits
long. The M5317TDX terminal is an example of a terminal with dynamic
endpoint identification. The SPID is used by the MISP to identify the terminal
and to assign to it specific service attributes during layer 3 initialization.
Before layer 3 terminal initialization can start, layer 2 must be fully
established, which includes TEI assignment. The TEI may be Dynamic (the
MISP assigns an unassigned TEI) or Static (the TEI in manually entered on
the terminal key pad). The terminal must then have its SPID number entered
at the terminal key pad.
Layer 3 initialization with dynamic endpoint identification starts when the
terminal transmits its SPID to the MISP using an information message. The
MISP acknowledges the message and sends an endpoint identifier message
that contains two identification parameters; the User Service Identifier
(USID) and the Terminal Identifier (TID).
Initializing terminal without dynamic endpoint identification
For an initializing terminal that does not support the dynamic end-point
identification the end-point identification parameters USID and TID are not
automatically assigned by the MISP.
Option 11C ISDN BRI Administration and Maintenance