Planning The Network; General; Network Information Tables (Nits) - Texas Instruments 990 User Manual

Planning the Network
Section 2
Planning the Network
2.1 GENERAL
This section provides background information on planning the
communications network prior to actually constructing it. Once
the network has been constructed at the primary station,
additional secondary stations and applications programs can be
added by repeating the network generation process. However, it
is possi ble to make provisions dur i ng the ini ti al desi gn for the
inclusion of future secondary stations and applications programs.
Therefore, careful consideration of future expansion needs, both
short term and long term, is needed during the planning phase.
By including anticipated additions in the initial design, they
can be brought online with a minimum of effort.
The network planning process involves developing plans for
constructing the primary station and each secondary station. In
each case, the principle concern is assigning numerical values to
identify each station and each applications program that will be
part of the network.
Examples of the requi red networ k parameters are gi ven in this
section, as well as sample forms that can be used to provi de the
users of the networ k wi th permanent documentation.
2.2 NETIDRK ADDRESSING
The DXIO HDLC Communications Package provides support for as many
as 32 secondary stations attached to each multipoint line. This
is an electrical limitation. Within the primary station, the
number of applications programs that can use the communications
package is limited only by the capacity of the computer.
The individual responsible for constructing the network assigns a
network identification number (network ID) to each station
address and each applications program (task) that will use the
comm un i ca t ions pac ka ge • Thi s ena bl es the comm un i ca t ions pac ka ge
to route information to the correct location. The network IDs
assigned to the stations and applications programs are stored in
network information tables (NITs).
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