M (Normative)  Enhancements to the access security for IP based services to enable NAT traversal for signaling messages |R7|  Word‑p. 53

M.0  General |R12|

M.1  Scope

M.2  References

M.3  Definitions, symbols and abbreviations

M.4  Overview of the security architecture

M.5  Security features  Word‑p. 54

M.6  Security mechanisms

M.6.1  Authentication and key agreement

M.6.2  Confidentiality mechanisms

M.6.3  Integrity mechanisms

M.6.4  Hiding mechanisms  Word‑p. 55

M.6.5  CSCF interoperating with proxy located in a non-IMS network

M.7  Security association set-up procedure

M.7.0  General |R12|

M.7.1  Security association parameters

M.7.2  Set-up of security associations (successful case)  Word‑p. 59

M.7.3  Error cases in the set-up of security associations  Word‑p. 64

M.7.3.1  Error cases related to IMS AKA

M.7.3.2  Error cases related to the Security-Set-up

M.7.3.2.1  Proposal unacceptable to P CSCF

M.7.3.2.2  Proposal unacceptable to UE

M.7.3.2.3  Failed consistency check of Security-Set-up lines at the P CSCF

M.7.3.2.4  Missing NAT traversal capabilities in the presence of a NAT

M.7.4  Authenticated re-registration

M.7.4.0  General |R12|

M.7.4.1  Void

M.7.4.1a  Management of security associations in the UE  Word‑p. 65

M.7.4.2  Void

M.7.4.2a  Management of security associations in the P CSCF

M.7.5  Rules for security association handling when the UE changes IP address  Word‑p. 66

M.8  ISIM  Word‑p. 67

M.9  IMC |R8|

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