A.11 Mobile Initiated De-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

IMS de-registration is initiated on the UE. The SS waits for the UE to send a REGISTER request, in accordance with 3GPP TS 24.229 [7], clause 5.1.1.6.

Expected sequence:

Step

Direction

Message

Comment

UE

SS

0A

🡪

SUBSCRIBE

Optional: The UE unsubscribes from one of its subscribed to event packages.

0B

🡨

200 OK

If the UE sent SUBSCRIBE, the SS responds to SUBSCRIBE with 200 OK.

0C

🡨

NOTIFY

If the UE sent SUBSCRIBE, the SS sends a final NOTIFY

0D

🡪

200 OK

If the UE sent SUBSCRIBE, the UE responds to NOTIFY with 200 OK.

1

🡪

REGISTER

The UE sends a de-registration request for IMS services.

2

🡨

200 OK

The SS responds to REGISTER with 200 OK.

Note 1: Steps 0A-0D may be repeated for any or all event packages subscribed to by the UE. It is the UE’s decision which unsubscriptions to perform.

Note 2: The UE can send the 200 OK for NOTIFY (step 0D) after the REGISTER request (step 1) or even not send it at all.

Specific message contents

SUBSCRIBE (step 0A)

Use the default message “SUBSCRIBE for reg-event package” in Annex A.1.4 of TS 34.229-1 [2] or “SUBSCRIBE for conference event package” in Annex A.5.1 of TS 34.229-1 [2] or “SUBSCRIBE for message-summary event package” in Annex A.6.1 of TS 34.229-1 [2], and with the following exceptions:

Header/param

Cond

Value/remark

Rel

Reference

From

addr-spec

Same as in original SUBSCRIBE that set up the corresponding subscription

tag

Same as in original SUBSCRIBE that set up the corresponding subscription

To

addr-spec

As specified in TS 34.229-1 [2] Annex A.1.4/A.5.1/A.6.1

tag

Same as in 200 OK for original SUBSCRIBE that set up the corresponding subscription

CSeq

value

value of the previous SUBSCRIBE sent by the UE for this dialog incremented by one

method

SUBSCRIBE

Expires

delta-seconds

0

200 OK for SUBSCRIBE (step 0B)

Use the default message “200 OK for SUBSCRIBE” in Annex A.1.5, A.5.2 or A.6.3 of TS 34.229-1 [2], whatever appropriate, with the following exceptions:

Header/param

Cond

Value/remark

Rel

Reference

To

RFC 3261 [6]

addr-spec

As specified in TS 34.229-1 [2] Annex A.1.4/A.5.1/A.6.1

tag

Same as in step 0A

Expires

RFC 3261 [6]

delta-seconds

0

NOTIFY (step 0C)

Header/param

Cond

Value/remark

Rel

Reference

Request-Line

RFC 3261 [6]

Method

NOTIFY

Request-URI

UE’s contact address in SIP URI form, as provided in the Contact header within the SUBSCRIBE creating the dialog

SIP-Version

SIP/2.0

Via

order of the parameters in this header must be like in this table

RFC 3261 [6]

via-param1:

sent-protocol

SIP/2.0/UDP when using UDP or
SIP/2.0/TCP when using TCP

sent-by

IP address and protected server port of SS

via-branch

value starting with ‘z9hG4bK’ (NOTE 1)

via-param2:

sent-protocol

SIP/2.0/UDP when using UDP or
SIP/2.0/TCP when using TCP

sent-by

scscf.3gpp.org

via-branch

value starting with ‘z9hG4bK’ (NOTE 1)

From

RFC 3261 [6]

addr-spec

same URI as received in the To header of the corresponding SUBSCRIBE message

tag

same as to-tag in step 0A

To

RFC 3261 [6]

addr-spec

same URI as received in the From header of the corresponding SUBSCRIBE message

tag

same as from-tag in step 0A

Call-ID

RFC 3261 [6]

callid

same as value received in SUBSCRIBE message

CSeq

RFC 3261 [6]

value

1

method

NOTIFY

Contact

RFC 3261 [6]

addr-spec

A1

<sip:scscf.3gpp.org>

addr-spec

A2

sip:final@conf-factory. appended with px_IMS_HomeDomainName

addr-spec

A3

<scscf.3gpp.org>

Event

RFC 6665 [28]
RFC 3680 [18]

event-type

A1

reg

event-type

A2

conference

event-type

A3

message-summary

Max-Forwards

RFC 3261 [6]

value

69

Subscription-State

RFC 6665 [28]

substate-value

terminated

Content-Length

value

0

Condition

Explanation

A1

Final NOTIFY sent for reg-event

A2

Final NOTIFY sent for conf-event

A3

Final NOTIFY sent for message-summary

NOTE 1: Branch parameter values sent by SS are different within a test case execution.

200 OK (step 0D)

Use the default message "200 OK for other requests than REGISTER or SUBSCRIBE" in Annex A.3.1 of TS 34.229-1 [2].

REGISTER (step 1)

Use the default message “REGISTER” in Annex A.1.1 of TS 34.229-1 [1] with conditions A2 and A17 "UE initiated IMS re-registration or de-registration" with the following exceptions:

Header/param

Cond

Value/remark

Rel

Reference

Contact

RFC 3261 [6]

addr-spec

SIP URI with IP address or FQDN and protected server port of the UE, AND,
if the UE supports GRUU, the following parameter:

+sip.instance="<urn:gsma:imei: (gsma-specifier-defined-substring)>”, OR
*

expires

0 (if present)

Expires

(must be present if addr-spec is *)

RFC 3261 [6]

delta-seconds

0 (if present)

Supported

header may be missing or it may contain any value

Authorization

value not checked

NOTE: In contrast to Annex A.1.1 of TS 34.229-1 [2], the Contact header does not have any further mandatory feature parameters.

200 OK (step 2)

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

Header/param

Cond

Value/remark

Rel

Reference

Contact

RFC 3261 [6]

addr-spec

same value as in REGISTER request if "*" is not included in the Contact header field of the REGISTER request in step 1
same value as in the Contact header field of the "200 OK" response to the initial registration if "*" is included in the Contact header field of the REGISTER request in step 1 (NOTE)

expires

0

NOTE: According to 3GPP TS 24.229 [7] clause 5.4.1.4.1 when the S-CSCF gets a wild-carded contact address for de-registration it shall include all de-registered contact addresses in the contact header of the 200 OK response ⇒ there is no “*” in DL