CA1246726A - Arrangement for communication between equipment belonging to different network architectures - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A communications network (K) provides the integration of at least two networks with different network architectures (SNA, DCNA, DECNET).
The communications network as such exhibits its own specific network architecture (ICNA) independent of the aforementioned architectures.
To the selector system (V) of the network are connected pieces of conversion equipment (CEI, CDI, CSI, CIE, CIS, CID). Pieces of equipment for different network architectures are capable of being linked via the aforementioned pieces of conversion equipment.
Connections between equipment belonging to the specific network architecture (ICNA) and a second network architecture are routed via a piece of conversion equipment and connections between equipment belonging to two other network architectures are routed via two pieces of conversion equipment wired in series.

Description

~Z4ti7Z6 ..

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 ~ O `~ ,~\~
~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 . ~.

lZ4~726

-2- 71504-7 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 fi ', '}b.

1;~4~7Z~
-2a- 71504-7 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 :

lZ4~26 . ., -2b- 71504-7 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.

lZ4~726 . .
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 ~Z4~726 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 :~Z4~726 .. s 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 `~ 124~726 , 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.

~7-124~726 -6a- 71504-7 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.

~24~726 .

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 lZ4f~72~

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.

Claims (5)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An arrangement for enabling communication between any two pieces of equipment, such as terminals and processors, in a communications network comprising one specific network architec-ture, said pieces of equipment having a network architecture of either said specific network architecture or another network architecture within a group of at least two different network 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 establish-ing a connection between pieces of equipment having the same network architecture via the selector means without any conver-sion equipment, second means for establishing a connection between pieces of equipment, a first one of which having the specific network architecture and a second having a second network archi-tecture, 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.

2. A method of enabling communication between any two pieces of equipment, such as terminals and processors, in a com-munications network comprising one specific network architecture, said pieces of equipment having a network architecture of either said specific network architecture or another network architec-ture within a group of at least two different network architec-tures, 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 connec-ted to the selector means, said method comprising: a) identifying said two pieces of equipment to be connected and their associated network architectures, and thereafter: b1) establishing a connec-tion between pieces of equipment having the same network archi-tecture via the selector means without any conversion equipment, b2) establishing a connection via the selector means and a single piece of conversion equipment between pieces of equipment, a first one of which having the specific network architecture and a second having a second network architecture, and b3) estab-lishing a connection successively via the selector means, a first piece of conversion equipment, the selector means again and a second piece of conversion equipment between pieces of equip-ment having two different network architectures, other than the specific network architecture.

3. A method as recited in claim 1 which comprises, prior to performing said step a) the steps of: i) connecting pieces of processor equipment with architectures other than said specific architecture to said selector means via a connection network, said connection network having a node directly connected to the piece of processor equipment and two parallel branches coupled to said selector means, one of said branches including essen-tially only a conductor and the other branch including a piece of conversion equipment for converting signals associated with said specific architecture to the architecture associated with said piece of processor equipment, and ii) connecting a plurality of pieces of different conversion equipment to said selector means, each said piece of conversion equipment with an input from said selector means and an output to said selector means.

4. A method of enabling communication between two pieces of equipment, such as terminals and processors, in a communications network comprising one specific network architecture, said pieces of equipment having different network architectures selected from a group of network architectures all of which are different from said specific network architecture, said communications network including selector means for establishing connections between various pieces of equipment, conversion equipment and path selec-tion equipment, both said conversion equipment and path selection equipment being connected to the selector means, said method comprising: a) identifying said two pieces of equipment to be connected and their associated network architectures, and b) es-tablishing a connection between said two pieces of equipment successively via the selector means, a first piece of conversion equipment, the selector means again and a second piece of con-version equipment.

5. A method as recited in claim 4 which comprises, prior to performing said step a) the steps of: i) connecting pieces of processor equipment with architectures other than said specific architecture to said selector means via a connection network, said connection network having a node directly connected to the piece of processor equipment and two parallel branches coupled to said selector means, one of said branches including essentially only a conductor and the other branch including a piece of conversion equipment for converting signals associated with said specific architecture to the architecture associated with said piece of processor equipment, and ii) connecting a plurality of pieces of different conversion equipment to said selector means, each said piece of conversion equipment with an input from said selector means and an output to said selector means.