Amtelco infinity series, Техническое руководство

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Using “D” Messages for Layer 3 • 8-10 •
The H.110 Basic Rate ISDN Board
Terminal equipment designed for NI-1 will send its SPID or SPIDs upon
assignment of TEI’s during power up or a resetting of the interface. A
separate data link and TEI will be associated with each SPID. The TE will
expect to receive an Endpoint Identifier for each SPID from the network
switch in reply, and will not function until it receives an INFOrmation
message with that element. The Endpoint Identifier consists of two
number, the User Service Identifier or USID and the Terminal Identifier or
TID. These are not to be confused with the SPID or TEI. The network
switch may or may not use the Endpoint Identifier in call processing
messages.
For ports that are set as TEs, the SPID is sent to the network switch by
using a message of the form
DIxxS where xx is one of two data link
arguments that are of the same form as the B-channels associated with the
port. If no number follows the “S”, the board will use the default SPID
programmed into the board using the “SD” command (see section 4.3). If
no default is programmed, the SPID digits must follow the “S”. The
Endpoint Identifier reply will be in a response message of the form
DIxxEuutt where xx is the data link argument, uu is the USID, and tt is the
TID. Both of these numbers are in hexadecimal. Note that the SPID for
the even data link argument is used for speech and audio calls and the
SPID for the odd data link argument is used for data calls. If only one
SPID is defined, it is used for both and should be assigned to the even data
link.
For terminal equipment connected to ports defined as NT, the programmed
SPID can be any number with at least 12 digits. Only the last digit is used.
The SPID for speech or audio calls for the first terminal should have a “1”
as the twelfth digit. If the terminal uses a separate SPID for data calls, this
should have a “2” as the twelfth digit. A second terminal should have a “3”
as the twelfth digit. The board will automatically respond with an Endpoint
Identifier messages. Endpoint identifiers are assigned on a fixed basis based
on the SPID.