A.3 IMS Emergency Registration / 5GS

34.229-53GPPInternet Protocol (IP) multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP)Part 5: Protocol conformance specification using 5G System (5GS)Release 16TSUser Equipment (UE) conformance specification

Test procedure:

1) SS waits for the UE to send an initial REGISTER request.

2) The SS responds to the initial REGISTER request with a valid 401 Unauthorized response.

3) The SS waits for the UE to set up a temporary set of security associations and to send another REGISTER request over those security associations.

4) The SS responds to the second REGISTER request with valid 200 OK response, sent over the same temporary set of security associations that the UE used for sending the REGISTER request.

Expected sequence:

Step	Direction		Message	Comment
	UE	SS
1	🡪		REGISTER	The UE sends initial IMS emergency registration
2	🡨		401 Unauthorized	The SS responds with a valid AKAv1-MD5 authentication challenge and security mechanisms supported by the network.
3	🡪		REGISTER	The UE completes the security negotiation procedures, sets up a temporary set of SAs and uses those for sending another REGISTER with AKAv1-MD5 credentials.
4	🡨		200 OK	The SS responds with 200 OK.

Specific Message Contents:

REGISTER (Step 1)

Use the default message “REGISTER” in Annex A.1.1 of TS 34.229-1 [2] with conditions A1 and A7.

401 Unauthorized (Step 2)

Use the default message “401 Unauthorized for REGISTER” in Annex A.1.2 of TS 34.229-1 [2] with condition A1.

REGISTER (Step 3)

Use the default message “REGISTER” in Annex A.1.1 of TS 34.229-1 [2] with conditions A2, A7, and A32.

200 OK for REGISTER (Step 4)

Use the default message “200 OK for REGISTER” in Annex A.1.3 of TS 34.229-1 [2] with condition A3.