ISIM and ISIM Parameters


< Parameters for Registration >


: Based on 24.229 Parameters contained in the ISIM

  • the private user identity : specified in IMPI
  • one or more public user identities : specified in IMPU (This field can have multiple items in it)
  • the home network domain name used to address the SIP REGISTER request


< Parameters for Emergency Registration >


: Based on 24.229 Parameters contained in the ISIM

  • The first item in IMPU


< ISIM Parameters : Specified in 31.103 >


EF_DOMAIN : This field contains Home Operators Network Domain. Data format (Encoding) of this field is as follows.


The Home Network Domain Name, i.e. FQDN shall be encoded to an octet string according to UTF-8 encoding rules as specified in IETF RFC 3629. The tag value of the Home Network Domain Name TLV(Tag Length Value) data object shall be '80'


EF_IMPU : This field contains IMS public user identity. This field can have one or more records. According to 3GPP 31.103, The first (or only) record in the EF shall be used when performing emergency registration; oras the default SIP Identity in case that no record is explicitly selected either in the current session or as a carryover from a prior session.


EF_IMPI : This field contains IMS priviate user identity. (See 31.103 4.2.2)


EF_P-CSCF : This field contains one or more Proxy Call Session Control Function addresses. The first record in the EF shall be considered to be of the highest priority. The last record in the EF shall be considered to be the lowest priority

Note : If service n1 and/or service n5 is "available", this file shall be present.


EF_GBABP : GBABP stands for GBA Bootstrapping parameters. This field contains the AKA Random challenge (RAND) and Bootstrapping Transaction Identifier (B-TID) associated with a GBA bootstrapping procedure (See 31.103 4.2.9)

Note : If service n2 is "available", this file shall be present.


EF_IST : This field contains ISIM Service Table. (See 31.103 4.2.7)


      Service n1: P-CSCF address

      Service n2 Generic Bootstrapping Architecture (GBA)

      Service n3 HTTP Digest

      Service n4 GBA-based Local Key Establishment Mechanism

      Service n5 Support of P-CSCF discovery for IMS Local Break Out

      Service n6 Short Message Storage (SMS)

      Service n7 Short Message Status Reports (SMSR)

      Service n8 Support for SM-over-IP including data download via SMS-PP as defined in TS 31.111

      Service n9 Communication Control for IMS by ISIM

      Service n10 Support of UICC access to IMS