WO1997004573A1

WO1997004573A1 - Procedure for modification of a protocol by means of an adaptive protocol

Info

Publication number: WO1997004573A1
Application number: PCT/SE1996/000929
Authority: WO
Inventors: Thomas Persson
Original assignee: Telia Ab
Priority date: 1995-07-20
Filing date: 1996-07-09
Publication date: 1997-02-06
Also published as: SE9502685L; SE9502685D0; SE514977C2

Abstract

The invention relates to a procedure for modification of a protocol by means of an adaptive protocol. The invention implies that a modified protocol object is published by a party who wants modification to concerned other parties. The protocol object is defined by identifier, layer and description. Receiving parties return a confirmation which accepts or rejects the modification. If the modification relates to a removal from the protocol, receiving party need not accept it. The protocol object can relate to an operation, an argument or a data type. The invention allows automatic updating of protocol without intervention by people.

Description

APPLICANT: TELIA AB

TITLE OF THE INVENTION: _D . , . ,-• . . _<,

Procedure for modification of a protocol by means of an adaptive protocol

TECHNICAL FIELD

The present invention relates to a procedure for modification of a protocol which is included in a telecommunication system. The invention allows that new functionality can be added to the protocol, without that the in the protocol included layers need to be reconstructed, by utilizing an adaptive protocol.

By making a protocol adaptive one can easily increase the functionality of the protocol without the need to make any construction changes in the included layers in the protocol. In addition it is possible to, during operation, change the protocol without first having to stop the system or the subsystem. An adaptive protocol is also usable when a protocol standard is upgraded or when new or already existing products are extended with new functionality. The technical problem the invention intends to solve, consequently is to provide a protocol which allows adaptivity so that one, without needing to reconstruct the protocol, can extend the functionality in the system.

PRIOR ART

Within the field there are a number of documents known. U.S. 5 224 098 describes a method which allows that an application program utilizes a transport protocol which differs from the original protocol. For instance by that a program which originates from a certain network with a certain protocol is run in another network with another protocol. The method implies that all transport functions which are required by the program are converted to a standardized protocol. When another user which utilizes another protocol wants to utilize the application, the node is informed when the program is run about how the protocol shall be compensated.

U.S. 4 905 282 relates to a protocol which allows that opposite parties (modems) can negotiate about which functions that shall be included in the protocol. One of the modems can after a normal handshaking procedure transmit a list over wanted functions, at which this other modem can accept the functions or return a list over functions that they support. U.S. 4 956 852 describes a method to make it possible to configure a modem in a communication system. The method allows that a first modem can read which functions that another modem supports. The first modem also can modify the functions of the other modem by setting it in test position. U.S. 4 928 306 shows a telephone which can be configured dynamically. The telephone implements a protocol which allows that it can be configured by receiving commands and parameters from a central point, for instance a PABX (Private Automatic Branch Exchange).

WO 94/6251 relates to a network structure and a signal protocol in a telecommunication network. The signal protocol allows that new services are added which are implemented only by the two opposite parties. A general signal protocol supports additions of new services by being divided into one basic protocol and into one or more service specific protocols. This allows that services are added or removed without the basic protocol being changed.

EP-A-555 997 shows an apparatus and a method to implement protocols. The communication can be made over just any protocol by in a general protocol transmitting a description of the protocol that is wanted. Prior art does not satisfactorily solves the problem to automatically update a protocol. The present invention provides a mechanism which allows simple addition and removal of functionalities so that the protocol is automatically modified, and at right party and at right layer, without reconstruction of the layers.

SUMMARY OF THE INVENTION

The solution implies briefly that the adaptivity is effected by a publication mechanism which informs opposite parties which make use of a given protocol that additions have been made to the protocol. The mechanism is in itself a protocol which offers and handles a lot of operations, arguments and data types. The essential feature in the mechanism is that one either tries to publish an object and gets a confirmation back from the opposite party, or that one removes an object. By publishing is meant that the offer of the new object can be transmitted to a number of parties, where each of the parties can accept or reject the object. Different revisions of the basic protocol therefore can exist. The invention consequently allows that the process to update a protocol can be automatized.

Consequently the present invention provide a procedure for modification of a protocol at parties in a telecommunication system by means of an adaptive protocol. According to the invention a modified protocol object is published by a party which wants a modification to concerned other parties which receive the publication. The protocol object is defined by an identifier, a layer and a description. The invention is described more in details in the enclosed patent claims.

SHORT DESCRIPTION OF THE DRAWINGS

The invention will in the following be described in details with references to enclosed drawings, where:

Figure 1 is a block diagram over communication between two parties,

Figure 2 is a corresponding block diagram over change of a protocol P on layer N-2 by means of the present invention, and

Figure 3 is a flow chart over an example of change of a protocol.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The present invention accordingly provides a procedure which allows a change of protocol in telecommunication systems. The procedure is in itself a protocol which is adaptive.

By a protocol being adaptive, one can in a simple way add new functionality to the protocol without needing to reconstruct the in the protocol included layers. Moreover it is possible to, during operation, change the protocol without stopping the system. This is useful when one has a protocol standard, and when new or existing products are upgraded, which certainly follows the standard but have some more functions which they offer. By means of the adaptivity the products then can adjust the protocol so that the new functionality directly can be offered.

The adaptivity in a protocol implies according to the invention that one by a publication mechanism informs opposite parties who use a given protocol that additions have been made to the protocol.

In Figure 1 is shown an example of communication between two parties. Suppose that there is a protocol P and parties A and B which communicate via the protocol on a certain layer N. If A or B wants to extend its own functionality this usually results in an extension of the common protocol P on layer N. Suppose that A has got an extended functionality and wants to extend the protocol P. A then uses the adaptivity mechanism in the protocol stack to publish the extension in protocol P. B then can communicate this to other layers in the protocol stack and self make use of this information.

The mechanism is in itself a protocol which offers a discrete number of operations.

The mechanism can handle operations, arguments and data types. Depending on how one indicates the relation to other operations, arguments and data types, the extent of an operation, an argument or a data type is decided. Operations, arguments or data types are examples of protocol objects.

The essential feature in the mechanism is that one either tries to publish an object and gets back a confirmation from the opposite party, or that one removes an object. If one removes an object no confirmation is needed, since one all the time shall have possibility to fall back on the basic protocol without problems arising. It can for instance be that one party gets a fault which makes that a certain operation can not be used for a longer period, and then the party shall have possibility to withdraw the offered operation whithout other parties having to acknowledge this.

By publishing is meant that the offer of the new object can be transmitted to a number of parties, where each can accept or reject the offer. Publishing party keeps count of who has accepted the new object. Different revisions of the basic protocol therefore can exist,

Built into the mechanism are textual descriptions in plain language of the published object in order that above lying applications, for instance help-applications, shall get information about what happens with the protocol. There also is a formal description which for instance can be written with the notation ASN.l.

Addressing of opposite party, error management and notation are made according to current protocol.

To make the adaptivity mechanism work, it must be implemented up to at least layer N to be able to adapt the protocol stack up to layer N. In addition the protocol must on any of the layers up to layer N have possibilty to handle the protocol object of the adaptivity mechanism. With today's protocols this often means that the own objects of the mechanism exist on application or session layer in the OSI-stack, which results in that the adaptivity mechanism is implemented from at least the session layer and downwards. Layers with mechanisms which cannot directly communicate with each other, call the mechanism of above lying layer.

Figure 2 shows how the protocol P on layer N-2 is extended by the mechanism on layer N-2 calling the mechanism on layer N-l, which in its turn calls the mechanism on layer N, which can communicate with opposite party via the own protocol object of the mechanism. The publication is then transmitted downwards to layer N-2, after which a confirmation is made from layer N-2 and upwards and back.

The mechanism of the adaptive protocol is described below with regard to the different operations and definitions. For the sake of understanding and for that the mechanism in itself is independent of way of notation, it is described in pseudo-form. However, one can of course chose a way of notation, for instance ASN.l if one would like. At additions to the protocol, the modifying party publishes to the opposite party the new operation with its parameters. The operation expects a confirmation from the opposite party. The following arguments exist in the operation: Identifier, layer and description. The identifier indicates the identification of the new operation. The layer indicates which layer in the protocol stack that shall be modified. The description contains a textual description of the new operation which gives possibility to update manual pages etc. and a description according to current notation which describes the new operation with for instance ASN.l, or another notation.

At removal from the protocol, the modifying party publishes to the opposite party that a certain operation no longer is current in the protocol. Arguments in the operation are following. Identifier indicates the identification of the operation. Layer indicates which layer in the protocol stack that shall be modified. Reason is a textual and a formal description of the reason for the withdrawal of the operation. Party which has received a publication via the operation "Publish addition" returns to the publishing party a confirmation which either accepts or rejects the published operation for use in the protocol. The following arguments exist. Identifier indicates the identification of the published operation. Layer indicates which layer in the protocol stack that shall be modified. Confirmation indicates acceptans or rejection.

At addition of new argument the modifying party publishes for the opposite party the new argument that shall be added to an already known operation. The following arguments are used. Operation identifier indicates the identity of the known operation. If the argument is not indicated, the argument is supposed to be current for all operations. Layer indicates which layer in the protocol stack that shall be modified. Argument identifier indicates the identity of the new argument. Textual description is a description of the argument in plain language. Description according to current notation is the new argument described in formal way.

At removal of argument the modifying party publishes to oppposite party that an argument is no longer current in the protocol. Arguments in the operation are the following. Operation identifier is the identification of the operation. If the argument is not indicated, this is current for all operations. Argument identifier indicates the identity of the argument. Layer indicates which layer in the protocol stack that shall be modified. Reason is a textual and a formal description of the reason for withdrawal of the argument. Party which has received a publication via the operation "Publish new argument" returns to the publishing party a confirmation which either accepts or rejects the published argument for use in the protocol. The following arguments exist. Operation identifier indicates the identification of the operation. If the argument was given in the preceding operation it is also indicated here. Argument identifier indicates the identification of the published argument. Layer indicates which layer in the protocol stack that shall be modified. Confirmation indicates acceptans or rejection. At addition of a new type of data the modifying party publishes for the opposite party the new data type that shall be added to an already known operation or argument. Depending on which identifiers that are given, the size of the field of application for the data type is decided. If, for instance, no operation identifier is indicated, the data type is global in the protocol. The following arguments are used. Operation identifier indicates the identity of the known operation. If the argument is not indicated, the publication is current for all operations. Argument identifier indicates the identity of the known argument. If the argument is not indicated, the data type is current for all arguments in an operation, or for all arguments in the protocol. This depends on whether an operation identifier is indicated. The union between the operation identifier and the argument identifier indicates the extent of the publication. Data type identifiers indicate the identity of the new argument. Layer indicates which layer in the protocol stack that shall be modified. Textual description is a description of the data type in plain language. Description according to current notation describes the new data type in formal way. At removal of a data type the modifying party publishes to opposite party that a data type is no longer current in the protocol. Arguments in the operation are according to the following. Operation identifier indicates the identity of the known operation. If the argument is not indicated, the removal is current for all operations. Argument identifier indicates the identity of the known argument. If the argument is not indicated, this is current for all arguments in an operation, or for all arguments in the protocol, depending on whether an operation identifier has been indicated. The union between the operation identifier and the argument identifier indicates the extent of the removal. Data type identifier indicates the identity of the data type. Layer indicates which layer in the protocol stack that shall be modified. Reason is a textual and formal description of the reason for the withdrawal of the data type.

Party which has received a publication via the operation "Publish new data type" returns to the publishing party a confirmation which either accepts or rejects the published data type for use in the protocol. The following arguments are used. Operation identifier indicates the identity of the known operation. If the argument was indicated in the preceding operation, it is also indicated here. Argument identifier indicates the current argument. If the identifier was indicated in the preceding operation, it is also indicated here. Data type identifier indicates the identification of the published data type. Layer indicates which layer in the protocol stack that shall be modified. Confirmation indicates acceptance or rejection.

EXAMPLE

Figure 3 shows an example which illustrates the invention. Suppose that we have a Service Control Point (SCP) and a Service Switching Point (SSP) which has the standard protocol INAP (intelligent Network Access Protocol) between them. In the INAP protocol is an operation which can be transmitted from SCP to SSP and which is called "Route to". The operation asks for a connection to a telephone number. Now suppose that another manufacturer of SSP has an extra function which can create three-party conference. He/she then wants to have possibility to offer this by adding an operation called "Three-party conference". By the publishing mechanism he/she then can publish this operation by transmitting the operation "Publish addition" via TCAP (the layer below INAP) with suitable choice of argument.

For instance:

• Publish addition of operation - Identifier:"Three-party conference"

- Layer: INAP

- Textual description:

"The operation offers three-party conference with local charge" - Description according to current notation ASN.l Ver.1.0:

The SSP then waits for a confirmation from the SCP: • Confirm addition of operation

- Identifier:"Three-party conference" - Layer: INAP

- Confirmation: Yes

After confirmation it is up to the applications on both sides to internally inform and make use of the new operation. For the network this probably will result in that the programmer of services sees the new operation in his/her tool box, with description and everything.

Consequently the invention provides an automatic procedure to update protocols. The invention eliminates moments with manual intervention by people. Previously one was forced to manually reprogram systems to add new parts of protocol. The invention also makes possible automatic change of protocol during operation. A preferred embodiment and an example has been described above. Many variations of the form of the invention can easily be realised by an expert in the field. The invention is only restricted by the following patent claims.

Claims

PATENT CLAIMS

1. Procedure for modification of a protocol at parties in a telecommunication system by means of an adaptive protocol, c h a r a c t e r i z e d in that a modified protocol object is published by a party who wants a modification to concerned other parties which receive the publication, which protocol object is defined by an identifier, a layer and a description,

2. Procedure according to patent claim 1, c h a r a c t e r i z e d in that the modification implies an addition to the protocol, at which receiving party returns a confirmation which accepts or rejects the addition.

3. Procedure according to patent claim 1, c h a r a c t e r i z e d in that the modification implies a removal in the protocol, at which receiving party returns a confirmation which accepts or rejects the removal.

4. Procedure according to patent claim 2 or 3, c h a r a c t e r i z e d in that the publishing party registers which receiving parties that have accepted the modification.

5. Procedure according to any of the patent claims 1-4, c h a r a c t e r i z e d in that the protocol object is an operation.

6. Procedure according to any of the patent claims 1-4, c h a r a c t e r i z e d in that the protocol object is an argument which moreover can be defined for which operation it relates to.

7. Procedure according to any of the patent claims 1-4, c h a r a c t e r i z e d in that the protocol object is a data type which moreover can be defined for which operation and which argument it relates to.

8. Procedure according to any of the previous patent claims, c h a r a c t e r i z e d in that the layer indicates which layer in the protocol stack that shall be modified.

9. Procedure according to any of the previous patent claims, c h a r a c t e r i z e d in that the description includes a textual description in plain language and a description with formal notation.

10. Procedure according to patent claim 9, c h a r a c t e r i z e d in that the formal notation is written with ASN.l.