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⟦733c38c96⟧ Wang Wps File
Length: 4391 (0x1127)
Types: Wang Wps File
Notes: Hannovermesse h>ndbog
Names: »1967A «
Derivation
└─⟦9d741eb69⟧ Bits:30006099 8" Wang WCS floppy, CR 0152A
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WangText
DEFENSE DATA
COMMUNICATIONS
1982-03-31
CHRISTIAN ROVSING
A/S
Page
#
III DEFENSE DATA COMMUNICATION
ENGAGEMENT AT CHRISTIAN ROVSING A/S
G. MESSAGE SWITCHING - CRISP
C̲R̲I̲S̲P̲
1. O̲B̲J̲E̲C̲T̲I̲V̲E̲S̲
The CRISP (C̲omprehensive R̲oyal Navy Supply and Transport
Service I̲nventory S̲ystem ̲Product) objective is to rationalize
handling of naval stores. Seven existing systems -
each handling different inventory aspects - will be
replaced by one system - CRISP. The locations serviced
by CRISP are shown in figure 1.
2. B̲E̲N̲E̲F̲I̲T̲
The following benefits are made available by CRISP:
o All information can be accessed from one terminal;
this gives fast response.
o All input/output in standard formats; this results
in rationalized staff training and better service
to the users.
o Availability is maximized; The network can continue
to operate even if several nodes out of service;
adaption to failures is automatic.
o Expansibility is accomodated; the network can be
expanded by virtually unlimited addition of existing
modules.
o Ease of maintenance; the ISO seven layer model
facilitates updates.
o Ease of operation; the status of all network components
is monitored on one FEPS console.
Figure 1
CRISP TP NETWORK
Serving locations throughout GB
3. S̲Y̲S̲T̲E̲M̲ ̲F̲U̲N̲C̲T̲I̲O̲N̲S̲ ̲
The CR80 software, depicted in fig. 2, consists of
a number of programs run in parallel. The data transfer
modules shown at the left are structured to conform
with the ISO - Open Systems Interconnection - Basic
Reference Model.
o The P̲H̲Y̲S̲I̲C̲A̲L̲ level consists of 9600 baud X25 links.
o The L̲I̲N̲K̲ level provides HDLC framing of data and
error control so that data corrupted by transmission
errors on the X25 links can be resent.
o The N̲E̲T̲W̲O̲R̲K̲ level routes the data to the destination.
It also guarantees that messages from one front
end to another are delivered in sequence, irrespective
of the routes the messages have taken.
Fig. 2
CRISP ARCHITECTURE
implemeting CR80 FEPS/RPS software
o The T̲R̲A̲N̲S̲P̲O̲R̲T̲ Station uses segmenting or blocking
of data to optimise the use of the network for
minimum cost. Flow and end-to-end control are
also provided by the Transport Station.
o The S̲E̲S̲S̲I̲O̲N̲ Control is used for establishing connections
between front ends and to provide synchronization,
thus avoiding duplication of data if a connection
breaks down and then is reestablished.
o The P̲R̲E̲S̲E̲N̲T̲A̲T̲I̲O̲N̲ layer - here divided into several
sublayers - provides the transformation between
the applications' data format and the internal
CR80 representation. This layer also guarantees
that data is exchanged between the applications
in an orderly way.
o The CRISP A̲P̲P̲L̲I̲C̲A̲T̲I̲O̲N̲ layer consists of mainframes,
terminals and printers communicating with each
other.
4. E̲Q̲U̲I̲P̲M̲E̲N̲T̲
ICL and CR hardware are used.
Three ICL 2976 mainframes are each connected to a CR80
Front End Packet Switch, i.e. 3 CR80's in all. The
FEPS's are linked together to form an inner ring.
The five Remote Packet Switches are each linked to
two FEPS's to form a reliable packet switched network.
ICL 7500 series cluster controllers are then connected
to the FEPS's and RPS's. Each cluster handles up to
eight Video Terminals and four Hard Copy Printers.
Printers may also be connected directly to the CR80.
Figure 3 shows a photograph of site installed CRISP
front end computers.
Figure 3
CRISP SITE
Showing the front-end computers
5. E̲X̲P̲A̲N̲D̲A̲B̲I̲L̲I̲T̲Y̲
Expandability is accomodated by addition of existing
modules; future expansion will neither demand new modules
nor render existing modules obsolete.
