Evaluating initial filter criteria
AssigneeTelefonaktiebolaget LM Ericsson (publ)
InventorsHubert Przybysz, Alf Heidermark, Timo Forsman
Life of this patent
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Abstract
A method of evaluating Initial Filter Criteria (IFC) at a terminating Serving Call Session Control Function (S-CSCF) in an IP Multimedia Subsystem network. Upon receiving a Session Initiation Protocol (SIP) message containing a destination Uniform Resource Identifier (URI), the S-CSCF applies an Initial Filter Criterion to the message, sends the message to an Application Server (AS), and suspends further IFC evaluation. When a return message is received from the AS, the S-CSCF determines whether the AS changed the URI. If so, the S-CSCF makes a determination of whether to resume IFC evaluation. If the AS did not change the URI, the S-CSCF resumes IFC evaluation.
Claims10
A method of evaluating Initial Filter Criteria at a terminating Call Session Control Function in an IP Multimedia Subsystem network, the method comprising:
- receiving a Session Initiation Protocol message, the Session Initiation Protocol message including an original Request-Uniform Resource Identifier;
- applying an Initial Filter Criterion to the message;
- as a result of applying the Initial Filter Criterion to the message, sending the message to an Application Server and suspending evaluation of further Initial Filter Criteria;
- receiving the message returned from the Application Server;
- determining whether the original Request-Uniform Resource Identifier has been changed by the Application Server to a changed Request-Uniform Resource Identifier;
- when the original Request-Uniform Resource Identifier has been changed by the Application Server:
- determining whether to resume evaluation of Initial Filter Criteria;
- upon determining not to resume evaluation of Initial Filter Criteria, passing the message directly to outgoing message handling in the Call Session Control Function;
- and
- upon determining to resume evaluation of Initial Filter Criteria, resuming evaluation of Initial Filter Criteria utilizing the changed Request-Uniform Resource Identifier;
- and
- when the original Request-Uniform Resource Identifier has not been changed by the Application Server, resuming evaluation of Initial Filter Criteria utilizing the original Request-Uniform Resource Identifier.
A terminating Call Session Control Function for use in an IP Multimedia Subsystem network, the Call Session Control Function comprising a processor coupled to a non-transitory memory that stores computer program instructions, wherein when the processor executes the computer program instructions, the Call Session Control Function is caused to:
- receive a Session Initiation Protocol message, the message including an original Request-Uniform Resource Identifier;
- evaluate Initial Filter Criteria to apply to the message;
- send the message to an Application Server;
- receive the message returned from the Application Server;
- determine whether the original Request-Uniform Resource Identifier has been changed by the Application Server;
- when the original Request-Uniform Resource Identifier has been changed by the Application Server:
- determine whether to continue evaluating Initial Filter Criteria;
- upon determining not to continue evaluating Initial Filter Criteria, pass the message directly to outgoing message handling in the Call Session Control Function;
- and
- upon determining to continue evaluating Initial Filter Criteria, resume evaluation of Initial Filter Criteria utilizing the changed Request-Uniform Resource Identifier;
- and
- resume evaluation of Initial Filter Criteria when the original Request-Uniform Resource Identifier has not been changed by the Application Server.
Dependencies are inferred from the claim text.