Fault tolerant service-providing apparatus for use in a telecommunications network

Service providing apparatus for providing telephonic voice and data call processing services to a switching center of a telecommunications network, said switching center being operative to establish temporary telephonic voice and/or data call connections between separate end users, said services being provided for telephonic voice and/or data call segments which the switching center sets up, maintains, and clears, said service-providing apparatus comprising:

• first service logic apparatus for normally providing said services to the switching center, at least in respect of set up of call segments, in response to requests for such services, at least some of said services involving multiple service-provision actions by the first service logic apparatus;
• second service logic apparatus for providing said services to the switching center in case of failure of the first service logic apparatus;
• recovery apparatus responsive to failure of the first service logic apparatus to bring into operation said second service logic apparatus;
• and
• a backup store;
• the first service logic apparatus, when providing a service involving multiple service-provision actions for a particular call segment, being operative only after at least some of service-provision actions, if any, that are required during set-up of said particular call segment have been completed, to save to said backup store state data held by the first service logic apparatus on service provision to said particular call segment, and said second service logic apparatus, on being brought into operation, retrieving from said backup store, at least when needed, said state data stored therein by the first service logic apparatus, said state data being needed by said second service logic apparatus to complete the provision to said particular call segment of the service which the first service logic apparatus was providing when the first service logic apparatus failed.

A telecommunications network operative to establish temporary telephonic voice and/or data call connections between separate end users, said telecommunications network comprising:

• a switching system for effecting basic telephonic voice and data call processing to set up, maintain and clear telephonic voice and/or data calls, the switching system treating each telephonic voice and/or data call as including at least one call portion and the switching system being operative to set-up, maintain and clear each such call portion;
• telephonic voice and data service providing apparatus communicating with the switching system for providing telephonic voice and data services additional to said basic call processing;
• interface apparatus for interfacing the switching system with the service providing apparatus whereby to enable the switching system to
• (a) request service provision for a particular call portion from the service providing apparatus, to
• (b) report, to the service providing apparatus, progress through a process of set-up, maintenance and clearance of said particular call portion, and to
• (c) enable the service providing apparatus to influence said process according to the service being provided by the service providing apparatus;
• wherein:
• said interface apparatus is operative to report to the service providing apparatus when set-up of said particular call portion is at least partially complete;
• and
• the service providing apparatus includes
• first service logic apparatus for normally providing said services to the switching system,
• second service logic apparatus for providing said services to the switching system in case of failure of the first service logic apparatus,
• recovery apparatus responsive to failure of the first service logic apparatus to bring into operation said second service logic apparatus, and a backup store;
• the first service logic apparatus, when providing a service involving multiple service-provision actions for said particular call segment, being operative to save to said backup store call-portion related data held by the first service logic apparatus concerning each call portion for which it is currently providing services, the saving of data about said particular call portion being effected only after said interface apparatus has reported that set-up of said particular call portion has been at least partially completed, and said second service logic apparatus, on being brought into operation, being provided from said backup store with the call-portion related data which is necessary to enable said second service logic apparatus to complete the provision of which the first service logic apparatus was providing when the first service logic apparatus failed.

A method for providing telephonic voice and/or data call processing services to a switching center of a telecommunications network, said switching center being operative to establish temporary telephonic voice and/or data call connections between separate end users, said services being provided for telephonic voice and/or data call segments which the switching center sets up, maintains, and clears, said method comprising:

• normally providing said services to the switching center by first service logic apparatus, at least in respect of set up of call segments, in response to requests for such services, at least some of said services involving multiple service-provision actions by the service logic apparatus;
• saving to a backup store by the first service logic apparatus, when providing a service involving multiple service-provision actions for a particular call segment, state data held by the first service logic apparatus concerning service provision to said particular call segment, the saving of state data being effected for said particular call segment only after the first service logic apparatus has determined that it has substantially completed at least some of said service-provision actions, if any, that are required during set up of said particular call segment;
• and
• upon failure of said first service logic apparatus, bringing into operation by recovery apparatus responsive to said failure a second service logic apparatus for rendering said services to the switching center, said second service logic apparatus, on being brought into operation, retrieving from said backup store state data which is necessary to enable said second service logic apparatus to complete the provision to said particular call segment of services which the first service logic apparatus was providing when the first service logic apparatus failed.

A method for providing telephonic voice and/or data call processing services to a switching center of a telecommunications network, said switching center being operative to establish temporary telephonic voice and/or data call connections between separate end users, said services being provided for telephonic voice and/or data call segments which the switching center sets up, maintains, and clears, said method comprising:

• normally providing said services to the switching center by first service logic apparatus, at least in respect of set up of call segments, in response to requests for such services, at least some of said services involving multiple service-provision actions by the first service logic apparatus;
• saving to a backup store by the first service logic apparatus, when providing a service involving multiple service-provision actions for a particular call segment, state data held by the first service logic apparatus concerning service provision to said particular call segment, the saving of state data being effected for said particular call segment only after at least some of set-up process for the segment have been completed;
• and
• upon failure of said first service logic apparatus, bringing into operation by recovery apparatus responsive to said failure a second service logic apparatus for rendering said services to the switching center, said second service logic apparatus, on being brought into operation, retrieving from said backup store, state data which is necessary to enable said second service logic apparatus to complete the provision to said particular call segment of services which the first service logic apparatus was providing when the first service logic apparatus failed.

A method of operating a telecommunications network operative to establish temporary telephonic voice and/or data call connections between separate end users, said telecommunications network including

• a switching system for effecting basic telephonic voice and/or data call processing to set up, maintain and clear calls, the switching system treating each call as including at least one call portion and the switching system being operative to set-up, maintain and clear each such call portion;
• telephonic voice and/or data service providing apparatus communicating with the switching system for providing telephonic voice and/or data services additional to said basic call processing;
• interface apparatus for interfacing the switching system with the service providing apparatus to enable the switching system to
• (a) request service provision from the service providing apparatus for a particular call portion, to
• (b) report, to the service providing apparatus, progress through a process of set-up, maintenance and clearance of said particular call portion, and to
• (c) enable the service providing apparatus to influence said process according to the service being provided by the service providing apparatus, the method comprising:
• operating said interface apparatus to report to the service providing apparatus when set-up of said particular call portion is at least substantially complete;
• providing first service logic apparatus for normally providing said services to the switching system, at least in respect of set-up of call segments, in response to requests for such services, at least some of said services involving multiple service-provision actions by the service logic apparatus, said first service logic apparatus being operative, only after said interface apparatus has reported that set-up of said particular call portion has been at least partially completed, to save to a backup store call-portion related data held by the first service logic apparatus concerning said particular call portion;
• and
• providing recovery apparatus, responsive to failure of said first service logic apparatus, to bring into operation a second service logic apparatus for providing said services to the switching system in case of failure of said first service logic apparatus, said second service logic apparatus, on being brought into operation, being provided from said backup store with said call-portion related data which is necessary to enable said second service logic apparatus to complete the provision of services on said particular call portion which the first service logic apparatus was providing when the first service logic apparatus failed.