O (Normative)  Enhancements to the access security to enable TLS |R8|  Word‑p. 76

O.1  TLS

O.1.1  TLS Access Security

O.1.2  Confidentiality protection

O.1.3  Integrity protection

O.1.4  TLS integrity protection indicator  Word‑p. 77

O.2  TLS Session set-up procedure

O.2.1  TLS Profile for TLS based access security

O.2.2  TLS session set-up during registration  Word‑p. 78

O.2.3  TLS session set-up prior to Initial registration |R12|  Word‑p. 79

O.3  Error cases in the set-up of TLS sessions

O.3.1  Error cases related to TLS

O.3.1.0  General |R12|

O.3.1.1  User authentication failure

O.3.1.2  Network authentication failure  Word‑p. 80

O.3.1.3  Synchronisation failure

O.3.1.4  Incomplete authentication

O.3.2  Error cases related to the Security-Set-Up

O.4  Management of TLS sessions

O.4.1  Management of TLS sessions at the UE

O.4.2  Management of TLS sessions at the P-CSCF

O.4.3  Authenticated re-registration

O.5  TLS Certificate Profile and Validation  Word‑p. 81

O.5.1  TLS Certificate

O.5.2  Certificate validation

O.5.3  Certificate Revocation  Word‑p. 82

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