Note: Descriptions are shown in the official language in which they were submitted.
S393~3
TITLE OF THE INVENTION
Arrangement for Path select;on ;n a commun;cat;ons_network
The present ;nvent;on relates to an arrangement ;n a communications
network, for example an ;ntegrated network for data, telephony, text
and/or ;mages. The arrangement compr;ses term;nals and computers
connected and/or capable of be;ng connected to the network, sa;d
computers be;ng able to Perform a var;ety of operat;ng tasks. Each
term;nal ;s capable of being l;nked to a des;red or random computer
wh;ch w;ll perform the operating task not;f;ed from the terminal
on act;vat;on.
DESCRIPTION OF THE PRIOR ART
The underly;ng concept for the use of the aforementioned terminals
and computers, that ;s to say host computers or host processors,
;n connection with the aforementioned network is that each terminal
shall be capable of being act;vated for the purpose of l;nking it
to the one computer or to any of the computers which is able to
execute the operating task which it ;s w;shed to have carried out
from the term;nal, on act;vat;on, and that the computers in the
netwQrk wh;ch perform the operat;ng tasks shall be ut;l;zed ir~ the
most effect;ve manner poss;ble and w;thout unnecessar;ly lengthy
wa;t;ng t;mes for each term;nal.
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One poss;bLe means by which the above problem may be solved is to
des;gn the term;nals ;n such a way that each term;nal ;s capable
largely of ;ts own accord of determining and controlling the
path via which a link with an unoccupied host computer can be
established.
DESCRIPTION OF THE PRESENT INVENTION
TECHNICAL PROBLEM
The solut;on env;saged does, however, ;nvolve the use of technically
compl;cated terminals which, for that reason, must be designed as
complete co~puters hav;ng, for example, their own software for the
internal processing of information received from and transmitted
to the network.
The wish ex~sts to be able to use term;nals of s;mple des;gn
for commun;cat;on with the network and the host computers, for
example term;nals of the teletype k;nd w;th a recorder and a
screen/pr;nt-out facility, etc. The Possibility of also connecting
complicated terminals to the network, if so desired, shall also
be provided.
SOLUTION
The pr;nc;pal object of the present ;nvention is to propose an
arrangement which will solve, amongst other things, the problem
outlined above. What may primarily be regarded as being
characteristic of the novel arrangement is that each terminal is
so arranged, when activated, as to cause linking with a piece of
path select;on equipment and transmission to it of a definition of
the type of work ;t ;s wished to have performed from the terniral.
Depend;ng on the nature of the aforement;oned def;n;t;on, the oath
select;on equ;pment w;ll transm;t back to the term;nal infor~at cr
relat;ng to the traff;c route to be allocated in the networ~ ~
the term;nal enabling it to be linked to a computer which is :tc~Cle
of perform;ng the task. Once the term;nal has received the
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aforementioned information in respect of the selected path, the
connection between the terminal and the path selection equipment
will be interrupted, allowing the terminal to utilize the infor-
mation transmitted from the path selection equipment in order
to effect a link of its own with the most suitable computer
available at that particular time, which must, of course, be
capable of performing the desired task. More specifically, the
invention is characterized in that the terminal, when activated,
is connected to a piece of path selection equipment and a trans-
mission to the path selection equipment of a definition of thetype of work to be performed is caused by input via the terminal,
and that each terminal transmits a code describing the design
and capacity of the terminal, in that the path selection equipment,
depending on the nature of the aforementioned definition and on
said code, sends back to the terminal information relating to
the traffic route to be allocated in the network to the terminal,
so that it can be connected to a computer which is capable of
performing the task, in that the path selection equipment or the
computer sends back informationto the terminal relating to the
required design and capacity of the terminal for performing the
type of work in question, and in that the connection between the
terminal and the path selection equipment is interrupted once
the terminal has received the aforementioned information.
In further developments of the idea of invention it
is proposed that the terminal shall be so arranged that, in the
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event of the aforementioned activation, it will cause automatic
linking to take place with the path selection equipment. Inter-
ruption of the connection to the path selection equipment once
the information in respect of the selected path has been trans-
mitted to the terminal should preferably be performed from the
terminal.
The network may incorporate one or more pieces of path
se]ection equipment which for this purpose can be positioned,
for example, at the outlets of an outgoing selector. It is also
possible to arrange a piece of path selection equipment in one
or more of the aforementioned host computers, for example in a
computer with which each terminal usually operates. Each piece
of path selection equipment is capable in one embodiment of being
called up from a host computer, for example when the terminal
is required to switch to another type of operating task, in
conjunction with the rearrangement of connections of high or low
priority, etc.
Each piece of path selection equipment should preferably
be capable of being controlled by means of one or more monitoring
organs arranged in the network and which control the path directing
function of each piece of path selection equipment. In the event
of it not being possible to establish communication paths from
the terminal, for example because of over-loading in the network,
the terminal will receive information to this effect from the
path selection equipment.
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The invention also incorporates further exchanges of
information between a terminal and the path selection equipment/
computers. Each terminal may, for example, receive notification
indicating whether
.. ~ .. . .. .
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.~Z~3B
;t ;s capable of act;ng as a rece;v;ng element ;n a g;ven operat;ng
task.
The object of the ;nvention will also function in networks wh;ch
represent the ;ntegrat;on of two or more networks with different
network arch;tectures. In this case the network will conta;n p;eces
of path select;on equ;pment wh;ch can serve each network architecture.
It will also be poss;ble ;n this ;nstance to make use of conversion
equipment enabl;ng term;nals for a f;rst network arch;tecture to be
utilized for communication with the computers of a second network
arch;tecture and of a th;rd network arch;tecure, and so on.
The direct;on of traffic paths within the network by the p;eces of
path select~on equ;pment should preferably be capable of be;ng
determ;ned on the bas;s of traffic measurements performed by the
computers and/or the conversion equipment of the network. The
lS computers and/or the pieces of conversion equ;pment ;nfluence the
pieces of path select;on equ;pment v;a central mon;tor;ng devices
;n the network.
ADVANTAGES
The invention permits the use of term;nals of s;mple des;gn at the
same time as the network function in its ent;rety can be used in an
optimal fash;on. The one or more Pieces of path select;on equ;pment
can continue to be suppl;ed w;th information ;n respect of the load
on the network and on the host computers and ;n respect of actual
needs, etc. The fac;lity for the allocation of pr;or;ty to
connections can be provided, and both s;mple and complicated terminals
can be connected to the network, etc. The ;nvention may be applied
with advantage to integrated networks which are able to serve
equipment designed for mutually different network arch;tectures,
in wh;ch case the use ;s also proposed of a component-saving
arrangement for the p;eces of convers;on equipment which are ~sed
for communicat;on between d;fferent types of equ;pment.
DESCRIPTION OF THE DRAWINGS
A preferred embod;ment of an arrangement wh;ch exh;b;ts the
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s;gn;f;cant character;st;c features of the invention is described
below with reference to the accompanying drawings, in which:
F;gure 1 shows in the form of a block diagram the bas;c
des;gn of a commun;cat;ons network having, amongst
other th;ngs, term;nals, processors and path
select;on equ;pment; and
F;gure Z shows in the form of a block d;agram the basic
des;gn of the central monitoring organs in the
network ;n accordance with Figure 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A commun;cat;ons network, for example an ;ntegrated network for data,
telephony, text and/or ;mages, is ;nd;cated by K ;n F;gure 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
princ;ple by means of a selector symbol V and inputs and outputs
in the network.
A number of term;nals T1, TZ, T3, T4 are connected to the network
via storage devices RT-~I, 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, P2, P3 and P4,
these des;gnations being able to represent not only the processors
but also mail boxes, text conference equ;pment, and connect;on
equ;pment to other networks, etc. The aforement;oned p;eces of
equipment can also ;nclude mult;plexers and concentrators. Each of
the term;nals T1-T4 shall be capable of being linked to the
aforementioned p;eces of equ;pment P1-P4 for the purpose of
perform;ng different operating tasks. The host computers are able
;n this respect to perform d;fferent operat;ng tasks. Two or more
computers can, of course, perform the same operating task, should
the need for the operating task in question to be Performed exist
with;n the network. Each of the terminals ;s thus capable of being
connected to one or more computers via the network.
In accordance with the invention, the des;gn ;llustrated includes
pieces of specific path selection equ;pment RI, RS, RD and RE, to
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which the term;nals are automatically linked v;a the network when
they are act;vated. The pieces of path select;on equipment are
connected to outlets ;n the selection network in accordance with
Figure 1, but may, as an alternat;ve 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 interest, for example, when a terminal
is used almost exclus;vely with a single processor, which is
provided in this way with a piece of path selection equipmen~ of
this kind.
]o In the embodiment shown, use is made of a network which provides
the integration of networks with a number, being in the case
illustrated three, of different network architectures. Terminals,
processors and Path selection equipment are provided in this case
for each of the network architectures, and also for the integrated
network as such.
The term;nal T1, the storage device RT-CI for path selection
;nformat;on, the path select;on equipment RI and the processor P4
are matched to the overall ;ntegrated network architecture,
referred to here as ICNA, which is the preferred designation for
the Integrated Communications Network Architecture used by the
Swed;sh Telecommun;cations Adm;nistration. T2, RT-S, RS and P4 are
matched to a network architecture ;n accordance with SNA (System
Network Architecture), which constitutes a first network
arch;tecture developed for a company. T3, RT-~ RD and T2 are
contained in the DCNA (D;str;buted Communication Network
Architecture) network architecure, which constitutes a second
network arch;tecture developed for a company. T4, RT-E, RE and P1
are conta;ned in the DECNET (Digital Equipment Computer Network)
network architecture, which constitutes a third network
architecture developed for a company.
In order to Permit communication between terminals and processors
of different architectures, the network design includes CIS
conversion equ;pment, which is conversion equipment between ICNA
and SNA. Similarly, CIE is convers;on equipment between ICNA and
DECNET, CID between ICNA and DCNA, CSI between SNA and ICNA (which
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can be the same as CIS), CEI between DECNET and ICNA (which can be
the same as CIE), and CDI between DCNA and ICNA (which can be the
same as CID).
The aforementioned architectures SNA, DCNA and DECNET represent at
the present time the most common network architectures and trace
routines. ICNA overlaps all three of the aforementioned architectures
and presupposes the use of OSI, on condition that OSI has been
defined.
When one terminal of the aforementioned term;nals T1-T4 ;s occupied
or ;s act;vated, it w;ll be connected automat;cally to the path
selection equipment RI, RS, RD or RE of the group or architecture
to which it belongs. The operator initiates his 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 into
path selection information which is transmitted back to the storage
device of the term;nal, that is to say to one of the p;eces of path
select;on equipment RT-~I, RT-S, RT-~ or RT-E. The storage equipment
for the terminal concerned controls the establ;shment of the
connect;on to that processor which is able to perform the task.
Each piece of path selection equipment may conveniently also be so
arranged as to provide automatic switching over from one computer
which is already linked, to another computer. This may be of
interest if the operating task at the terminal changes, and if it
is w;shed to have performed another type of work which the computer
concerned is unable to execute. Another reason for the aforementioned
switching 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 00re terminals are executed in
~ 30 such a way that each term;nal for each computer and/or each piece
;~ of path select;on equipment is able to transmit a code wh;ch
descr;bes the characterist;cs and execution of the term;nal, for
example the key arrangement, graph;cs, capab;l;t;es, colour, and
pr;nt-out capab;lities, etc. The path select;on equ;pment ;s able
;n a preferred embodiment to take ;nto account the aforementioned
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terminal character;st;cs when select;ng the computer. The path
selection equipment notifies the terminal of any restr1ctions on
the uses 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 desired.
The aforement;oned information can also be provided by the computer
;f information relating to the type of terminal is transmitted
further to the computer.
D;fferent instances of trace routine convers;on may occur ;n
accordance w;th the above. If the terminal and the processor are
matched to the same arch;tecture and trace routine, no convers;on
equipment will be linked in. Conversion equipment will be requ;red
;f either the processor or the terminal is matched to ICNA. If
neither the terminal nor the processor is matched to ICNA, then
-L5 two pieces of conversion equ;pment w;ll requ;re to be linked
together v;a ICNA. The Table below shows the occas;ons when the
d;fferent p;eces of conversion equ;pment are requ;red.
Processor: INCA SNA DCNA DECNET
Term;nal
ICNA None CIS CID CIE
SNA CSI None CSI - CID CSI-CIE
DCNA CDI CDI-CIS None CDI-CIE
DECNET CEI CEI - CIS CEI-CID None
The concept for the equipment illustrated contains functions for
25 the control, monitor;ng and adm;n;strat;on of the network, which ;s
shown clearly ;n F;gure 2. The p;eces of path select;on equ;pment
connected to the network K ;n F;gure 1 are ;nd;cated ;n Figure 2
by the des;gnat;on R. The pieces of convers;on equ;pment and the
processors ;n accordance w;th F;gure 1 are ;ncluded ;n a sim;lar
fash;on ;n F;gure 2 and are ;nd;cated respect;vely by the
des;gnat;ons C and P. The central mon;toring organs ;n the network
are symbolized by CDP (eentral Mon;tor;ng Processors). Control
paths 1-6 are ;ndicated by arrows. The arrow 1 ;nd;cates the
poss;bility for changing the path selection information, the
blocking of certain traffic and/or the allocation of priority to
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certa;n traff;c v;a the P;eces of equ;pment R. The arrow 2 ind;cates
ava;lab;lity ;nformat;on and/or traff;c statistics from the path
selection equipment. The arrow 3 indicates availability information
and/or traffic statistics from the conversion equipment, whereas
5 the arrow 4 ;ndicates corresponding information or statistics from
the processors P. The processors can also be controlled so as to
allocate pr;ority to certain traffic, as indicated by the arrow 5.
The interrupt;on of certain connections, for example those with low
priority, can also be controlled; see the arrow 6.
The central mon;tor;ng processors may be of a prev;osuly d;sclosed
type and may ;nclude connect;ons for a pr;nter S, a screen ~ and
a keyboard TA, etc.
Changes to traffic path ;nformation shall be capable of being made
from appropriate central po;nts ;n the network, cf. CDP, wh;ch w;ll
arr;ve at the p;eces of path selection equ;pment R v;a separate
selectors. The term;nals and the operators must ;dentify themselves
to the path select;on equ;pment R so that the latter can select a
path or, ;f necessary, block traff;c on the basis of its orig;n.
Processors and p;eces of convers;on equ;pment shall meter their
traffic continuously and shall notify blocking s;tuations to the
central mon;toring po;nts of the network, wh;ch ;n turn control the
operat;on of the pa~h select;on equ;pment. The path select;on
equ;pment shall be able to commun;cate w;th the central mon;tor;ng
points of the network and shall not;fy any commun;cat;on
requ;rements wh;ch cannot be executed. The poss;b;l;ty shall be
afforded of ;nterrupt;ng connect;ons of low pr;or;ty v;a the
processors from a central po;nt ;n the network, should the
;nformat;on from the path select;on equ;pment so requ;re.
The ;nvent;on ;s not restr;cted to the embod;ment descr;bed above
by way of example, but may undergo mod;fcat;ons w;th;n the context
of the follow;ng Patent Cla;ms and the idea of invention.
