8.41 Communication Forwarding on No Reply: MO Voice Call initiation with preconditions

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

8.41.1 Test Purpose (TP)

(1)

with { UE being registered to IMS and configured to use preconditions and being made to initiate a voice call }

ensure that {

when { Voice call initiation progressed until 180 Ringing (including PRACK/200 OK) and UE receives 181 Call is being forwarded followed by 183 Session Progress }

then { UE completes call initiation with forwarded to UE by restarting from PRACK for 183 Session Progress }

}

8.41.2 Conformance Requirements

The conformance requirements covered in the present test case are, unless otherwise stated, Rel-15 requirements.

[TS 24.604, clause 4.2.1.4]:

The CFNR service enables a served user to have the network redirect to another user communications which are addressed to the served user’s address, and for which the connection is not established within a defined period of time. The CFNR service may operate on all communications, or just those associated with specified services. The served user’s ability to originate communications is unaffected by the CFNR supplementary service.

The CFNR service can only be invoked by the network after the communication has been offered to the served user and an indication that the called user is being informed of the communication has been received.

[TS 24.604, clause 4.5.2.1]:

When communication diversion has occurred on the served user side and the network option "Originating" user receives notification that his communication has been diverted (forwarded or deflected)" is set to true, the originating UA may receive a 181 (Call is being forwarded) response according to the procedures described in 3GPP TS 24.229.

The Information given by the History header could be displayed by the UA if it is a UE.

[TS 24.229, clause 9.2.3]:

Since the UE does not know that forking has occurred until a second provisional response arrives, the UE will request the radio/bearer resources as required by the first provisional response. For each subsequent provisional response that may be received, different alternative actions may be performed depending on the requirements in the SDP answer:

– the UE has sufficient radio/bearer resources to handle the media specified in the SDP of the subsequent provisional response, or

– the UE must request additional radio/bearer resources to accommodate the media specified in the SDP of the subsequent provisional response.

NOTE 1: When several forked responses are received, the resources requested by the UE is the "logical OR" of the resources indicated in the multiple responses to avoid allocation of unnecessary resources. The UE does not request more resources than proposed in the original INVITE request.

NOTE 2: When service-based local policy is applied, the UE receives the same authorization token for all forked requests/responses related to the same SIP session.

When an 199 (Early Dialog Terminated) response for the INVITE request is received for an early dialogue, the UE shall release reserved radio/bearer resources associated with that early dialogue.

When the first final 200 (OK) response for the INVITE request is received for one of the early dialogues, the UE proceeds to set up the SIP session using the radio/bearer resources required for this session. Upon the reception of the first final 200 (OK) response for the INVITE request, the UE shall release all unneeded radio/bearer resources.

GIBA:

NOTE 1: GIBA does not allow SIP requests to be protected using an IPsec security association because it does not perform a key agreement procedure.

8.41.3 Test description

8.41.3.1 Pre-test conditions

System Simulator:

– 1 NR Cell connected to 5GC, default parameters.

UE:

– The UE contains either ISIM and USIM applications or only USIM application on UICC.

– The UE is configured to register for IMS after switch on.

– The UE is configured to use preconditions.

Preamble:

– UE is in state 1N-A (TS 38.508-1 [21]) and registered to IMS

8.41.3.2 Test procedure sequence

Table 8.41.3.2-1: Main Behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

UE is made to attempt an IMS voice call.

–

–

–

–

2-7

Steps 2-7 of generic procedure specified in Table 4.9.15.2.2-1 of TS 38.508-1 [21] are performed.

–

–

–

–

–

EXCEPTION: In parallel with Step 8-12, parallel behaviour defined in table 8.41.3.2-2 takes place

–

–

–

–

8-12

Steps 1-5 as defined in Annex A.4.1a are executed.

–

–

–

–

12A

Step 10 of generic procedure specified in Table 4.9.15.2.2-1 of TS 38.508-1 [21] is performed.

–

–

–

–

–

EXCEPTION: In parallel to steps 12B and 12C below, step 13 occurs.

–

–

–

–

12B-12C

Steps 11-12 of generic procedure specified in Table 4.9.15.2.2-1 of TS 38.508-1 [21] are performed.

–

–

–

–

13-17

Steps 6-10 of Annex A.4.1a happen.

–

–

–

–

18

SS sends 181 response to indicate that call forwarding has been started as the user did not answer to the phone

<–

181 Call is being forwarded

–

–

19

SS (simulating the phone to which the call was forwarded) responds with 183 Session Progress containing an SDP answer indicating support for AMR-WB codec and state of the local preconditions.

<–

183 Session Progress

–

–

20

Check: Does the UE send PRACK for 183 Session Progress containing an SDP offer for negotiation with the UE which the call was forwarded to?

–>

PRACK

1

P

21

SS responds to PRACK containing an SDP answer.

<–

200 OK

22

The SS sends 180 Ringing response to the UE

<–

180 Ringing

–

–

23

UE acknowledges the receipt of 180 response by sending PRACK.

–>

PRACK

–

–

24

The SS responds PRACK with 200 OK.

<–

200 OK

–

–

25

The SS responds INVITE with 200 OK to indicate that the virtual remote UE had answered the call

<–

200 OK

–

–

26

The UE acknowledges the receipt of 200 OK for INVITE

–>

ACK

–

–

27

UE is made to release the call

–

–

–

–

28-29

Steps 1-2 in Annex A.7 are performed.

–

–

–

–

Table 8.41.3.2-2: Parallel behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

The UE transmits an RRCReconfigurationComplete message.

–>

NR RRC: RRCReconfigurationComplete

–

–

8.41.3.3 Specific message content

Table 8.41.3.3-1: 181 Call is being forwarded for INVITE (Step 18, table 8.41.3.2-1)

Derivation Path: TS 34.229-1 [2], Annex A.2.14.

Table 8.41.3.3-2: 183 Session Progress for INVITE (Step 19, table 8.41.3.2-1)

Derivation Path: TS 34.229-1 [2], Annex A.2.3, condition A1

Header/param

Cond

Value/remark

Rel

Reference

To

tag

different tag must be used than the one used in steps 8-17 as this response is now from another UE and belongs to another dialog instance. Note that this new tag must be used within the rest of the steps (18-29) in this test case instead of the tag used within steps 8-17

Contact

addr-spec

different URI must be used than the one used in step 9 as this is supposed now to represent another UE to which the call is being forwarded. Note that this new Contact must be used within the rest of the steps (20-21) in this test case.

Require

option-tag

precondition

Message-body

Same contents as specified in step 3 annex A.4.1a except for o-line:

o=- 1111111112 1111111111 IN (addrtype) (unicast-address for new remote UE).

RFC 4566 [38]

Table 8.41.3.3-3: PRACK (Step 20, table 8.41.3.2-1)

Derivation Path: Annex A.4.1a, step 6 UPDATE with o-line not being checked

Table 8.41.3.3-4: 200 OK for PRACK (Step 21 and 24, table 8.41.3.2-1)

Derivation Path: TS 34.229-1 [2], Annex A.3.1, conditions A10 and A22

Header/param

Cond

Value/remark

Rel

Reference

Require

option-tag

precondition

Content-Type

media-type

application/sdp

Content-Length

value

length of message-body

Message-body

SDP body of the 200 response copied from the received PRACK and modified as follows:

– IP address on "c=" lines and transport port on "m=" lines changed to indicate to which IP address and port the UE should start sending the media;

– "o=" line identical to previous SDP sent by SS except that sess-version is incremented;

– Attributes for preconditions: a=curr:qos remote sendrecv

Table 8.41.3.3-5: 180 Ringing for INVITE (Step 22, table 8.41.3.2-1)

Derivation Path: TS 34.229-1 [2], Annex A.2.4 with conditions A1 and A7

Header/param

Cond

Value/remark

Rel

Reference

Contact

addr-spec

Same value as in the 183 response of step 19

History-Info

hi-targeted-to-uri

Same value as in the 181 response of step 18

hi-index

Same value as in the 181 response of step 18

Table 8.41.3.3-5a: PRACK (Step 23, table 8.41.3.2-1)

Derivation Path: Annex A.4.1a, step 9.

Table 8.41.3.3-6: 200 OK for INVITE (Step 25, table 8.41.3.2-1)

Derivation Path: TS 34.229-1 [2], Annex A.3.1, conditions A1, A10, and A19

Header/param

Cond

Value/remark

Rel

Reference

Contact

addr-spec

Same value as in the 183 response of step 19

History-Info

hi-targeted-to-uri

Same value as in the 181 response of step 18

hi-index

Same value as in the 181 response of step 18

Table 8.41.3.3-7: ACK (Step 26, table 8.41.3.2-1)

Derivation Path: TS 34.229-1 [2], Annex A.2.7, conditions A1