Tech-invite 3GPPspace IETFspace

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Content for TR 29.826 Word version: 13.1.0

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2 References p. 5

3 Abbreviations p. 6

3.1 Abbreviations p. 6

4 Existing P-CSCF restoration procedures with WLAN p. 6

4.1 Existing P-CSCF restoration procedures in 3GPP p. 6

4.2 GSMA specifications related to P-CSCF restoration p. 7

4.3 Limitations and drawbacks p. 7

5 Objectives p. 8

6 Solution alternatives p. 9

6.1 Introduction p. 9

6.2 Basic mechanism solution p. 9

6.2.1 Basic mechanism for HSS based solution p. 9

6.2.1.1 Overview and principles p. 9

6.2.1.2 Description p. 9

6.2.1.3 Evaluation p. 12

6.3 Extended mechanism solutions p. 12

6.3.1 Solutions with a trusted WLAN p. 12

6.3.1.1 Solution T1 - PCO Based solution p. 12

6.3.1.1.1 Overview and principles p. 12

6.3.1.1.2 Description p. 13

6.3.1.1.3 Method to indicate the UE support for PCO based P-CSCF Restoration for TWAN to P-GW p. 14

6.3.1.1.4 Discussion about single and multi connection modes p. 14

6.3.1.1.5 Roaming cases p. 15

6.3.2 Solutions with an untrusted WLAN p. 15

6.3.2.1 Solution U1 - P-CSCF restoration extension for untrusted WLAN p. 15

6.3.2.1.1 Overview and principles p. 15

6.3.2.1.2 Description p. 15

6.3.2.1.3 Method to indicate the UE support of the P-CSCF restoration to P-GW p. 17

6.3.2.1.4 Coding between the ePDG and the UE p. 17

6.3.2.1.5 Roaming cases p. 18

6.4 Supported features and capabilities p. 18

6.4.1 Introduction p. 18

6.4.2 Feature support in the HSS and S-CSCF p. 18

6.4.3 Feature support in the 3GPP AAA Server p. 18

6.4.4 Feature support in the PGW p. 19

6.4.5 Feature support in the TWAN p. 19

6.4.6 Feature support in the ePDG p. 19

6.4.7 Capability support in the UE p. 19

7 Conclusions and recommendations p. 19

$ Change History p. 20