Storage of network data

A method for use in an IP Multimedia Subsystem (IMS), comprising the steps of:

• at a Serving Call/Session Control Function (S-CSCF), receiving a Session Initiation Protocol (SIP) message containing information relating to a private user identity/public user identity (IMPI/IMPU) pair;
• at the S-CSCF, identifying the type of information contained in the SIP message;
• at the S-CSCF, creating a new data package, containing the information, to be sent to and stored by a Home Subscriber Server (HSS);
• sending from the S-CSCF to the HSS a first Server-Assignment-Request (SAR) command containing an Attribute Value Pair (AVP) including an instruction to the HSS and the new data package;
• at the HSS, identifying whether or not a previous data package relating to the IMPI/IMPU pair is currently stored;
• if a previous data package relating to the IMPI/IMPU pair is not currently stored at the HSS, storing the new data package at the HSS;
• if a previous data package associated with the IMPI/IMPU pair is currently stored at the HSS, returning an error message from the HSS to the S-CSCF, the error message including the previously stored data package;
• at the S-CSCF, in response to the error message, creating a further data package which combines the information relating to the IMPI/IMPU pair received in the SIP message with the information contained in the previous data package;
• sending from the S-CSCF to the HSS a second SAR command containing an AVP including the instruction “STORE” and the further data package;
• and,
• storing the further data package at the HSS.

A method for use by a Serving Call/Session Control Function (S-CSCF) of an IP Multimedia Subsystem (IMS), comprising:

• receiving a Session Initiation Protocol (SIP) message containing information relating to a private user identity/public user identity (IMPI/IMPU) pair;
• identifying the type of information contained in the SIP message;
• creating a data package to be sent to and stored by a Home Subscriber Server (HSS), the data package including the information contained in the SIP message and a data label indicating the type of data so as to provide information to the HSS to enable it to store S-CSCF information in labelled, separately addressable, data packages tied to the IMPI/IMPU pair;
• and,
• sending to the HSS a Server-Assignment-Request (SAR) command containing an Attribute Value Pair (AVP) including an instruction to the HSS and the data package.

A Serving Call/Session Control Function (S-CSCF) assignable for serving a subscriber registered in an IP Multimedia Subsystem (IMS), the S-CSCF comprising:

• a receiver for receiving a Session Initiation Protocol (SIP) message containing information relating to a private user identity/public user identity (IMPI/IMPU) pair;
• a processor for identifying the type of information contained in the SIP message and creating a new data package, containing the information, to be sent to and stored by the HSS;
• and,
• a sender for sending to a Home Subscriber Server (HSS) a Server-Assignment-Request (SAR) command containing an Attribute Value Pair (AVP) including an instruction to the HSS and the new data package;
• wherein, if a previous data package for the IMPI/IMPU pair has been sent to the HSS for storage, then the processor is configured to combine the information relating to the IMPI/IMPU pair received in the SIP message with the information contained in the previous data package.

A Home Subscriber Server (HSS) holding subscriber data for subscribers of an IP Multimedia Subsystem (IMS), the HSS comprising:

• a receiver for receiving from a Serving Call/Session Control Function (S-CSCF) a Server-Assignment-Request (SAR) command containing an Attribute Value Pair (AVP) including an instruction to the HSS and a data package containing information taken from a SIP request relating to an IMPI/IMPU pair;
• storage means for storing the data package;
• a processor for identifying whether a previous data package relating to the IMPI/IMPU pair is currently stored in the storage means;
• and
• a sender configured to send an error message, including the previous data package relating to the IMPI/IMPU pair, to the S-CSCF if the previous data package is currently stored in the storage means, the storage means being configured to retain the previous data package;
• wherein, if the error message is sent, the receiver is configured to receive from the S-CSCF a second SAR command containing an AVP including the instruction “STORE” and a further data package, the further data package combining the information taken from the SIP request relating to the IMPI/IMPU pair with the information contained in the previous data package;
• and,
• wherein the storage means is configured to store the further data package.