Management of sequence numbers the example sequence

Info icon This preview shows pages 52–54. Sign up to view the full content.

View Full Document Right Arrow Icon
Management of sequence numbers The example sequence number management schemes in TS 33.102 [1] Informative Annex C can be used to ensure that the authentication failure rate due to synchronization failures to kept sufficiently low when the same sequence number mechanism and data is used for authentication in the PS/CS domains and in the IMS. This can be done by enhancing the method for the allocation of index values in the AuC/HSS so that authentication vectors distributed to different service domains shall always have different index values (i.e. separate ranges of index values are reserved for PS, CS and IMS operation). The AuC/HSS is required to obtain information about which type of service node has requested the authentication vectors. Reallocation of array elements to the IMS domain can be done in the AuC/HSS with no changes required to already deployed USIMs. As the possibility for out of order use of authentication vectors within the IMS service domain may be quite low, the number of PS or CS array elements that need to be reallocated to the IMS domain could be quite small. This means that the ability to support out of order authentication vectors within the PS and CS domains would not be significantly affected. Sequence number management is operator specific and for some proprietary schemes over the air updating of the UICC may be needed. 3GPP 3GPP TS 33.203 V12.67.0 (2014-0609) 52 Release 12
Image of page 52

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Annex H (normative): The use of "Security Mechanism Agreement for SIP Sessions" [21] for security mode set-up The BNF syntax of RFC 3329 [21] , with the addition of the "aes-cbc" value for the "ealg" parameter and the "UDP- enc-tun" value for the "mode" parameter, is defined for negotiating security associations for semi-manually keyed IPsec or TLS in the following way: security-client = "Security-Client" HCOLON sec-mechanism *(COMMA sec-mechanism) security-server = "Security-Server" HCOLON sec-mechanism *(COMMA sec-mechanism) security-verify = "Security-Verify" HCOLON sec-mechanism *(COMMA sec-mechanism) sec-mechanism = mechanism-name *(SEMI mech-parameters) mechanism-name = "ipsec-3gpp" / "tls" mech-parameters = ( preference / algorithm / protocol / mode / encrypt-algorithm / spi-c / spi-s / port-c / port-s ) preference = "q" EQUAL qvalue qvalue = ( "0" [ "." 0*3DIGIT ] ) / ( "1" [ "." 0*3("0") ] ) algorithm = "alg" EQUAL ( "hmac-md5-96" / "hmac-sha-1-96" ) protocol = "prot" EQUAL ( "ah" / "esp" ) mode = "mod" EQUAL ( "trans" / "tun" / "UDP-enc-tun" ) encrypt-algorithm = "ealg" EQUAL ( "des-ede3-cbc" / "aes-cbc" / "null" ) spi-c = "spi-c" EQUAL spivalue spi-s = "spi-s" EQUAL spivalue spivalue = 10DIGIT; 0 to 4294967295 port-c = "port-c" EQUAL port port-s = "port-s" EQUAL port port = 1*DIGIT The use of security association parameters is specified in clauses 7.1, 7.2, M.7.1 and M.7.2 of the present document. The parameters described by the BNF above have the following semantics: Mechanism-name: For manually keyed IPsec, this field includes the value "ipsec-3gpp". "ipsec-3gpp" mechanism extends the general negotiation procedure of RFC 3329 [21] in the following way: 1 The server shall store the Security-Client header received in the request before sending the response with the Security-Server header.
Image of page 53
Image of page 54
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern