Methods, systems, and computer program products for offloading call control services from a first network of a first type to a second network of a second type

A method for providing call control offload information to a requestor, the method comprising:

• at a call control offload function implemented at a network routing node:
• receiving, from switching office and in response to the switching office detecting a call originating from a calling party a first network of a first protocol type, a query requesting call control offload routing information that includes a calling party identifier;
• in response to receiving the query:
• performing a lookup in a call control offload database using the calling party identifier to obtain call control offload routing information used for offloading call control services for the call to a second network of a second protocol type different from the first protocol type and wherein the call offload routing information is usable to identify at least one IP multimedia subsystem (IMS) call session control function (CSCF) that facilitates providing of the call control services using nodes in the second network;
• and
• returning the call control offload routing information to the switching office so that the switching office can use the routing information to offload the call control services.

A system for offloading call control services from a first network of a first protocol type to a second network of a second protocol type, the system comprising:

• a network routing node including:
• a communications module configured to receive a query message from a switching office in response to the switching office detecting a call originating from a calling party in a first network of a first protocol type;
• and
• a call control offload function configured to determine routing information for a node in a second network of a second protocol type different from the first protocol type based on information identifying the calling party and configured to offload call control services to the second network using the node, wherein the node in the second network comprises an IP multimedia subsystem (IMS) call session control function (CSCF) that facilitates providing of the call control services using nodes in the second network and wherein the call control offload function provides the routing information to the switching office so that the switching office can use the routing information to offload the call control services.

A system for providing call control offload information to a requester, the system comprising:

• a network routing node including a call control offload function and a call control offload database;
• the call control offload function being associated with a first network of a first protocol type and configured to:
• receive from a switching office a query requesting call control offload routing information that includes a calling party identifier, the query being generated in response to the switching office detecting a call originating from a calling party corresponding to the calling party identifier and from the first network;
• in response to receiving the query, perform a lookup in a call control offload database using the calling party identifier to obtain call control offload routing information used for offloading call control services for a call involving the calling party identifier from the first network to a second network of a second protocol type different from the first protocol type and wherein the call offload routing information is usable to identify at least one IP multimedia subsystem (IMS) call session control function (CSCF) that facilitates providing of the call control services using nodes in the second network;
• and
• return the call control offload routing information to the switching office so that the switching office can use the routing information to offload call control services for the call to the second network.

A computer readable medium having stored thereon executable instructions that when executed by the processor of a computer control the computer to perform steps comprising:

• at a call control offload function implemented at a network routing node:
• receiving a query message in response to a switching office detecting a call originating from a calling party in a first network of a first protocol type;
• in response to receiving the query message:
• determining routing information for a node in a second network of a second protocol type different from the first protocol type based on information identifying the calling party;
• and
• offloading call control services to the second network using the node, wherein the node in the second network comprises an IP multimedia subsystem (IMS) call session control function (CSCF) that facilitates providing of the call control services using nodes in the second network, wherein offloading the call control services includes providing the routing information to the switching office and so that the switching office can use the routing information to offload the call control services.

A computer readable medium having stored thereon executable instructions that when executed by the processor of a computer controls the computer to perform steps comprising:

• at a call control offload function implemented at a network routing node:
• receiving from a switching office and in response to the switching office detecting a call originating from a calling party in a first network of a first protocol type, a query requesting call control offload routing information that includes a calling party identifier;
• in response to receiving the query:
• performing a lookup in a call control offload database using the calling party identifier to obtain call control offload routing information used for offloading call control services for the call to a second network of a second protocol type different from the first protocol type and wherein the call offload routing information is usable to identify at least one IP multimedia subsystem (IMS) call session control function (CSCF) that facilitates providing of the call control services using nodes in the second network;
• and
• returning the call control offload routing information to the switching office so that the switching office can use the routing information to offload the call control services.