8.8 Communication Forwarding Unconditional / Signalling / 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

8.8.1 Test Purpose (TP)

(1)

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

ensure that {

when { UE sends INVITE and receives a 181 Call Is Being Forwarded response }

then { UE continues and completes the voice call initiation }

}

8.8.2 Conformance Requirements

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

[TS 24.604, clause 4.2.1.2]:

The CFU service enables a served user to have the network redirect to another user communications which are addressed to the served user’s address. The CFU service may operate on all communication, or just those associated with specified services. The served user’s ability to originate communications is unaffected by the CFU supplementary service. After the CFU service has been activated, communications are forwarded independent of the status of the served user.

As a service provider option, a subscription option can be provided to enable the served user to receive an indication that the CFU service has been activated. This indication shall be provided when the served user originates a communication if the CFU service has been activated for the served user’s address and for the service requested for the communication.

The maximum number of diversions permitted for each communication is a service provider option. The service provider shall define the upper limit of diversions. When counting the number of diversions, all types of diversion are included.

[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.

8.8.3 Test description

8.8.3.1 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

8.8.3.2 Test procedure sequence

Table 8.8.3.2-1: 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 Steps 8-9, parallel behaviour defined in table 8.8.3.2-2 takes place

–

–

–

–

8-9

Steps 1-2 as defined in Annex A.4.1a are executed.

–

–

–

–

10

SS sends 181 response to indicate that call forwarding has been started as the user is configured to Communication Forwarding Unconditional.

<–

181 Call is being forwarded

–

–

11

SS (simulating the phone to which the call was forwarded) responds with 183 Session Progress containing an SDP answer.
(Step 3 of A.4.1a)

<–

183 Session Progress

–

–

12

Check: Does the UE send PRACK for 183 Session Progress
(Step 4 of A.4.1a)

–>

PRACK

1

P

13

SS responds to PRACK.

(Step 5 of A.4.1a)

<–

200 OK

–

–

13A

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 13B and 13C below, step 14 occurs.

–

–

–

–

13B-13C

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

–

–

–

–

14

Check: Does the UE send a second SDP offer in an UPDATE request?
(Step 6 of A.4.1a)

–>

UPDATE

1

P

15

SS responds to UPDATE.
(Step 7 of A.4.1a)

<–

200 OK

–

–

16

The SS sends 180 Ringing response to the UE
(Step 8 of A.4.1a)

<–

180 Ringing

–

–

17

UE acknowledges the receipt of 180 response by sending PRACK.
(Step 9 of A.4.1a)

–>

PRACK

–

–

18

The SS responds PRACK with 200 OK.
(Step 10 of A.4.1a)

<–

200 OK

–

–

19

The SS responds INVITE with 200 OK to indicate that the virtual remote UE had answered the call
(Step 11 of A.4.1a)

<–

200 OK

–

–

20

The UE acknowledges the receipt of 200 OK for INVITE
(Step12 of A.4.1a)

–>

ACK

–

–

21

Make the UE release the call.

–

–

–

–

22

UE releases the voice call.

(Steps 1-2 of Annex A.7.)

–

–

–

–

Table 8.8.3.2-2: Parallel behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

The UE transmits an RRCReconfigurationComplete message.

–>

NR RRC: RRCReconfigurationComplete

–

–

8.8.3.3 Specific message content

Table 8.8.3.3-1: 181 Call is being forwarded for INVITE (Step 10, table 8.8.3.2-1)

Derivation Path: TS 34.229-1 [2], Table in subclause A.2.14.

Table 8.8.3.3-2: 180 Ringing for INVITE (Step 16, table 8.8.3.2-1)

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

Header/param

Cond

Value/remark

Rel

Reference

History-Info

hi-targeted-to-uri

Same value as in the 181 response of step 10

hi-index

Same value as in the 181 response of step 10

Table 8.8.3.3-3: 200 OK for INVITE (Step 19, table 8.8.3.2-1)

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

Header/param

Cond

Value/remark

Rel

Reference

History-Info

hi-targeted-to-uri

Same value as in the 181 response of step 10

hi-index

Same value as in the 181 response of step 10