Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION
Arrangement for commun;cat;on between equ;pment belong;ng to
d;fferent network architectures.
The present invent;on relates to an arrangement perm;tt;ng
commun;cat;on between p;eces of equ;pment in a commun;cat;ons
network, for example an integrated network for data, telephony,
text and/or ;mages. The aforement;oned commun;cat;ons network is
also of the k;nd which, in pr;nciple, prov;des the ;ntegrat;on of
at least two networks w;th d;fferent network architectures. The
aforement;oned commun;cat;ons network is constructed w;th its own
spec;f;c network architecture ;ndependent of the architectures of
the aforement;oned two networks. There are connected to ~e selector
system of the commun;cat;ons network pieces of convers;on equipment
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~Li~ which connect;ons between pieces of equ;pment for d;fferent
network arch;tectures are capable of be;ng l;nked.
DESCRIPTION OF THE PRIOR ART
The d;fferent compan;es wh;ch market d;fferent p;eces of equipment
on the open market, for example computers and term;nals, etc., and
their assoc;ated communications systems, stipulate the use of
designs specific to that part;cular company, wh;ch means that the
system of one company w;ll not, as a general rule, be compatible
. ~.
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with the system of another company. The following may be men-
tioned as examples of previously disclosed systems: SNA (System
Network Architecture), DCNA (Distributed Communication Network
Architecture), and DECNET (Digital Equipment Computer Network).
DESCRIPTION OF THE PRESEN~ INVENTION
TECHNICAL PROBLEM
There isa general wish for the expansion of data communi-
cations networks of the type in question, to which connection is
possible and in which communication can be provided between the
pieces of equipment which are specific to the different companies.
This presupposes, amongst other things, the use of conversion
equipment, and it is desirable in this respect that the designs of
the components concerned should be simple, and that the range of
components should be kept to a minimum.
SOLUTION
One of the objects of the present invention is to solve
the problem outlined above, and what may be regarded in this
respect as being essentially characteristic of the novel arrange-
ment is that connections between pieces of equipment belonging
to the specific architecture, that is to say to the architecture
of the communications network, and a second network architecture
are routed via a piece of conversion equipment, and that connec-
tions between pieces of equipment belonging to two other network
archltectures are routed via two pieces of conversion equipment
wired in series.
In further developments of the idea of invention it is
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proposed that the first pieces of conversion equipment should be
so arranged as to be utilized for the conversion of link proto-
col between equipment in the specific network architecture
(i.e. that of the communications network) and equipment in each
of the aforementioned other network architectures, and that the
other pieces of conversion equipment should be so arranged as to
be wired in series with the aforementioned first pieces of con-
version equipment for the purpose of the conversion of link proto-
col between equipment belonging to two of the aforementioned
other network architectures.
The invention may be summarized, according to a first
broad aspect, as an arrangement for enabling communication between
any two pieces of equipment, such as terminals and processors,
in a communications network comprising one specific network
architecture, said pieces of equipment having a network architec-
ture of either said specific network architecture or another net-
work architecture within a group of at least two different net-
work architectures, said communications network including:
selector means for establishing connections between various pieces
of equipment, conversion equipment and path selection equipment,
both said conversion equipment and path selection equipment being
connected to the selector means, first means for establishing a
connection between pieces of equipment having the same network
architecture via the selector means without any conversion
equipment, second means for establishing a connection between
pieces of equipment, a first one of which having the specific
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network architecture and a second having a second network
architecture, said second means establishing said connection via
the selector means and a single piece of conversion equipment,
and third means for establishing a connection between pieces of
equipment having two different network architectures, other than
the specific network architecture, said third means establishing
said connection successively via the selector means, a first
piece of conversion equipment, the selector means again and a
second piece of conversion equipment.
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ADVANTAGES
The solution proposed above will permit t~e number of pieces of
conversion equipment to be kept to a minimum, at the same time as
a comparatively simple design can be retained for each of the
pieces of conversion equipment.
DESCRIPTION OF THE DRAWINGS
A preferred embodiment of an arrangement wh;ch exhibits the
s;gnificant characterist;c features of the invention is described
below with reference to the accompanying drawing.
10Figure 1 shows in the form of a bLock diagram the basic
design of a communications network having, amongst
other things, terminals, processors and path
selection equipment; and
Figure 2 shows in tne form of a block diagram the basic
15design of the central monitoring organs in the
networK in accordance with Figure 1.
DESCRIPTION OF THE PREFERRED EM~ODIMENT
A communications network, for instance an integrated network for
data, telephony, tcxt and/or images, is ind;cated by K in Figure
1. The des;gn of the network may be of a previously disclosed type
and will accordingly not be described here in detail, but is shown
only in principle by means of a selector symbol V and inputs and
outputs in the network.
A number of terminals T ~ T2, T3, T4 are connected to the network
via storage devices RT-J;~, RT-S, RT-~ and RT-E for the purpose of
determining the path selection in the network. To the network are
also connected host computers or processors P1, PZ, Pt and P4 ,
these designations being able to represent not only the processors
but also mail boxes, text conference equipment, and connection
equipment to other networks, etc. The aforementioned pieces of
;equipment can also include mu~tiplexers and concentrators. Each of
the terminals T1-T4 shall be capable of being linked to the
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aforement;oned pieces of equ;pment P1-P4 for the purpose of-
performing different operat;ng tas~s. In th;s respect the host
computers are able to perform d;fferent operat;ng tasks. Two or
more computers can, of course, perform the same operating task,
should the need for the operat;ng task ;n question to be performed
exist w;th;n the network. Each of the terminaLs is thus capable of
be;ng connected to one or more computers v;a the network.
In accordance with the invention, the design ;llustrated ;ncludes
pieces of specific path selection equipment RI, RS, RD and RE ,
to which the terminals are automatically connected via the network
when they are activated. The pieces of path selection equ;pment are
connected to outlets in the selection network ;n accordance with
Figure 1, but may, as an alternative or in addition, be arranged
inside or adjacent to one or more of the pieces of equipment P1-P4 .
The latter case will be of ;nterest, for example, when a term;nal
;s used almost exclus;vely w;th a s;ngle processor, which ;s
provided in this way with a piece of path selection equ;pment of
this kind.
In the embodiment shown, use is made of a network which prov;des
the ;ntegration of networks with a number, being in the case
illustrated three, of different network arch;tectures. Term;nals,
processors and path selection equipment are provided in th;s case
for each of the network arch;tectures, and also for the ;ntegrated
network as such.
The terminal T1 , the storage dev;ce RT-Cl for path selection
information, the path selection equipment RI and the Processor `
P4 are matched to the overall integrated network architecture,
referred to here as ICNA, which is the preferred designat;on for
the Integrated Communications Network Architecture used by the
Swedish Telecommun;cat;ons Administrat;on. T2, RT-S, RS and ~4f
are matched to a network architecture in accordance with SNA (System
Network Architecture), which constitutes a first network architecture
developed for a company. T3, RT-~, RD and T2 are contained ;n the
DCNA (Distributed Communication Network Architecture) network
architecture, which const;tutes a second network arch;tecture
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developed for a tompany. T4, RT-E, RE and Pl are contained in the
DECNET (D;g;tal Equ;pment Computer Network) network arch;tecture,
wh;ch const;tutes a th;rd network arch;tecture develoDed for a
company.
s In order to perm;t commun;cat;on between term;nals and processors
of d;fferent arch;tectures, the network des;gn ;ncludes CIS
convers;on equ;pment, wh;ch ;s convers;on equipment between ICNA
and SNA. S;m;larly, CIE ;s convers;on equ;pment between ICNA and
DECNET, CID between ICNA and DCNA, CSI between SNA and ICNA (wh;ch
can be the same as CIS), CEI between DECNET and ICNA (which can be
the same as C~E), and CDI between DCNA and ICNA (wh;ch can be the
same as CID).
The aforement;oned arch;tectures SNA, DCNA and DECNET represent
at the present t;me the most common network arch;tectures and
trace rout;nes. ICNA overlaps all three of the aforement;oned
arch;tectures and presupposes the use of OSI, on cond;t;on that
OSI has been def;ned.
When one term;nal of the aforement;oned term;nals Tt-T4 ;s
occup;ed or ;s act;vated, ;t w;ll be connected automat;cally to the
20 path select;on equ;pment RI, RS, RD or RE, of the group or
arch;tecture to wh;ch it belongs. The operator ;n;tiates h;s work
at the terminal by indicating the designation of the task which he
wishes to perform. The path selection equipment translates the name
; of the task ;nto path select;on ;nformat;on wh;ch ;s transm;tted
25 back to the storage dev;ce of the term;nal, that ;s to say to one
of the p;eces of path select;on equ;pment RT-CI, RT-S, RT-~ or
RT-E. The storage equ;pment for the term;nal concerned controls the
establ;shment of the connect;on to that processor wh;ch ;s able to
perform the task.
Each p;ece of path select;on equ;pment may conven;ently also be so
arranged as to prov;de automat;c sw;tch;ng over from one computer
wh;ch ;s already l;nked to another computer. Th;s may be of interest
;f the operating task at the term;nal changes, and if it is ~i5hed
to have performed another type of work wh;ch the computer concerned
;s unable to execute. Another reason for the aforement;oned switching
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over is that the computer concerned may be required to perform a
task of higher priority than that with which it is involved at
the time.
In a preferred embodiment one or more terminals are designed in
such a way that each terminal for each computer and/or each
piece of path selection equipment is able to transmit a code
which describes the characteristics and design of the terminal,
for example the key arrangement, graphics, capabilities, colour,
and print-out capabilities, etc. The path selection equipment
is able in a preferred embodiment to take into account the
aforementioned terminal characteristics when selecting the
computer. The path selection equipment notifies the terminal of
any restrictions on the use of the terminal for the desired task.
The path selection equipment can also notify the terminals of the
type of terminal which should be used if complete processing of
the task is desixed. The aforementioned information can also
be provided by the computer if information relating to the type
of terminal is transmitted further to the computer.
Different instances of link protocol conversion may occur in
accordance with above. If the terminal and the processor are
matched to the same architecture and trace routine, no conversion
equipment will be required. One piece of conversion equipment
will be required if either, (but not both) the processor or the
terminal is matched to ICNA. If neither the terminal nor the
processor is matched to ICNA, then two pieces of conversion
equipment will require to be linked in series via the network.
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The connection between the ICNA terminal Tl and the SNA processor
P3 is routed via the selector network V and the conversion
equipment CIS. Similarly, Tl is connected to Pl and P2 via CID
and CIE respectively. The connection between, for example, SNA
terminal T2 and the DCNA processor Pl is routed via the selector
network V, the conversion equipment CSI, the fixed connection 1,
once more through the selector network, and the conversion equip-
ment CID. T2 communicates with P2 via V, CDI, the connection 2,
V and CIE,and so o~.
The table below shows the occasions when the different pieces of
conversion equipment are required.
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Processor: INCA SNA DCNA DECNET
Terminal
ICNA None CIS CID CIE
SNA CSI None CSI-CID CSI-CIE
S DCNA CDI CDI-CIS None CDI-~IE
DECNET CEI CEI-CIS CEI-CID None
The concept for the equ;pment ;llustrated conta;ns funct~ons for
the control, monitor;ng and adm;n;strat;on of the network, wh;ch ;s
shown clearly ;n Figure 2. The p;eces of path selection equ;pment
connected to the network K ;n F;gure 1 are ;nd;cated in F;gure 2
by the des;gnat;on R . The p;eces of conversion equipment and
the processors in accordance with Figure 1 are included in a
similar fashion in Figure 2 and are ;nd;cated respect;vely by the
des;gnat;ons C and P. The centraL mon;tor;ng organs ;n the network
are symbolized by CDP (Central Monitoring Processors). Control
paths 1-~ are ;nd;cated by arrows. The arrow 1 ;nd;cates the
possibil;ty for chang;ng the path select;on ;nformat;on, the
blocking of certa;n traff;c and/or the allocation of pr;or;ty to
certa;n traffic v;a the pieces of equ;pment R . The arrow 2
;ndicates ava;labil;ty ;nformat;on andtor traff;c stat;st;cs from
the path selection equ;pment. The arrow 3 ;nd;cates availabil;ty
;nformat;on and/or traff;c stat;st;cs from the convers;on equ;pment,
whereas the arrow 4 ;nd;cates corresponding information or stat;st;cs
from the processors P. The processors can also be controlled so as
to allocate pr;or;ty to certa;n traff;c, as ;nd;cated by the arrow
5. The ;nterrupt;on of certain connect;ons, for example those w;th
low pr;or;ty, can also be controlled; see tne arrow 6.
The central mon;tor;ng processors may be of a prev;ously d;sclosed
type and may ;nclude connect;ons for a pr;nter S, a screen 8 and
a keyboard TA, etc.
Changes to traffic path ;nformation shall be capable of be;ng made
from appropr;ate central po;nts in the network, cf. CDP, wh;ch w;ll
arrive at the pieces of path selection equipment R via separate
selectors. The terminals and the operators must identify themselves
to the path selection equ;pment R so that the latter can select a
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path or, if necessary, block traffic on the basis of its orig~n.
Processors and pieces of conversion equipment shall meter their
traffic continuously and shall notify blocking situations to the
central monitoring points of the network, which in turn control
the operation of the path selection equipment. The path select;on
equipment shall be able to communicate with the central mon;toring
points of the network and shall notify any communication
requirements which cannot be executed. The possibility shall
be afforded of interrupting connections of low priority via the
processors from a central point in the network, should the
;nformat;on from the path selection equipment so require.
The ;nvent;on ;s not restricted to the embodiment described
above by way of example, but may undergo mod;fications within
the context of the following Patent Claims and the idea of
;nvent;on.
