U – S

Message

0

UE is made to put the first call on hold.

–

–

–

–

1-4

Steps 1-4 of A.17 are used to put the first call on hold.

–

Messages in Annex A.17

1

P

5

UE is made to initiate a second MTSI voice call.

–

–

–

–

6-10

Steps 1-5 of A.4.1 are performed.

–

Messages in in Annex A.4.1

2

P

–

EXCEPTION: Step 11-12 describes behaviour that takes place if the UE doesn’t include QOS confirmation in the PRACK message in step 9.

–

–

–

–

11

UE sends a second SDP offer in an UPDATE request.

(Step 6 of Annex A.4.1)

–>

UPDATE

2

P

12

SS responds to UPDATE, including an SDP answer.

(Step 7 of Annex A.4.1)

<–

200 OK

2

P

13-17

Steps 8-12 of A.4.1 are performed.

–

Messages in Annex A.4.1

2

P

18

UE is made to start a Multiparty Call

–

–

–

–

19-22

Steps 1-4 of A.17 are used to put the second call on hold.

–

–

3

P

23-35

Steps 1-13 of A.19 are used to create a conference.

–

–

4

P

36

UE sends REFER to invite user A to the conference.

(Step 1 of A.20)

–>

REFER

5

P

37-38

SS responds with a 202 final response and NOTIFY for the subscription created by the REFER.

(Steps 2-3 of A.20)

–

–

–

–

39

The UE responds the NOTIFY request with 200 OK.

(Step 4 of A.20)

–>

200 OK

6

P

40

SS responds with a NOTIFY to confirm the user the invited user was able to join the conference.

(Steps 5 of A.20)

–

NOTIFY

–

–

41

UE responds the NOTIFY request with 200 OK

(Steps 6 of A.20)

–>

200 OK

6

P

42-43

Conditional: If the UE has subscribed to the conference event package, then the SS sends a NOTIFY for conference event package and UE responds with 200 OK.

(Steps 7-8 of A.20)

–

–

–

–

44

UE sends REFER to invite user B to the conference.

(Step 1 of A.20)

–>

REFER

7

P

45-46

SS responds with a 202 final response and NOTIFY for the subscription created by the REFER.

(Steps 2-3 of A.20)

–

–

–

–

47

The UE responds the NOTIFY request with 200 OK.

(Step 4 of A.20)

–>

200 OK

8

P

48

SS responds with a NOTIFY to confirm the user the invited user was able to join the conference.

(Steps 5 of A.20)

–

NOTIFY

–

–

49

UE responds the NOTIFY request with 200 OK

(Steps 6 of A.20)

–>

200 OK

8

P

50-51

Conditional: If the UE has subscribed to the conference event package, then the SS sends a NOTIFY for conference event package and UE responds with 200 OK.

(Steps 7-8 of A.20)

–

–

–

–

52-53

Steps 1-2 of A.7 are used to release the first call.

–

–

–

–

54-55

Steps 1-2 of A.7 are used to release the second call.

–

–

–

–

56-57

Steps 1-2 of A.8 are used to release the active session.

–

–

–

–

58

Conditional: If the UE has subscribed the conference event package, then the SS notifies the UE that its subscription to conference event package is terminated

<–

NOTIFY

–

–

59

Conditional: If the SS sent NOTIFY, then the UE sends 200 OK for NOTIFY.

(Steps 8 of A.20)

–>

200 OK

–

–

Header/param

Cond

Value/remark

Rel

Reference

Request-Line

Request-URI

px_IMS_CalleeUri2

px_IMS_CalleeUri2 is used to invite another user to the session.

px_IMS_CalleeUri2 may be either SIP or Tel URI. It may contain a dialstring and phone-context parameter, when calling to dialstring. When calling to dialstring SIP URI must also contain user=phone or user=dialstring parameter.

The dialstring, if used, may be global, home local number or geo-local number. For home local numbers the value of phone-context parameter must equal the home domain name i.e. px_IMS_HomeDomainName. For geo-local numbers the home domain name must be prefixed by string “geo-local.” or access technology specific prefix, if the UE supports that option.

Note: The way how the UE determines whether numbers in a non-international format are geo-local, home-local or relating to another network, is UE implementation specific. For instance the UE might have a UI setting.

To

addr-spec

px_IMS_CalleeUri2

Header/param

Cond

Value/remark

Rel

Reference

Contact

addr-spec

px_IMS_CalleeContactUri2

Message-body

o=- 1111111112 1111111111 IN (addrtype) (unicast-address for SS)

RFC 4566 [38]

Header/param

Cond

Value/remark

Rel

Reference

Contact

addr-spec

px_IMS_CalleeContactUri2

Header/param

Cond

Value/remark

Rel

Reference

Contact

addr-spec

px_IMS_CalleeContactUri2

Header/param

Cond

Value/remark

Rel

Reference

Message-body

o=- 1111111113 1111111111 IN (addrtype) (unicast-address for SS)

RFC 4566 [38]

Header/param

Cond

Value/remark

Rel

Reference

Contact

addr-spec

px_IMS_CalleeContactUri2

Header/param

Cond

Value/remark

Rel

Reference

Require

(present, if Message-Body is present)

option-tag

precondition

Message-body

(if present)

Contents is copied from step 6 of annex A.4.1 with the following exceptions:

Attributes for preconditions:

a=curr:qos local sendrecv

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos optional remote sendrecv or a=des:qos mandatory remote sendrecv

TS 24.229 [7]

Header/param

Cond

Value/remark

Rel

Reference

To

tag

Same value as used in step 9

Require

(present, if Message-Body is present)

option-tag

precondition

Content-Type

(present, if content type was present in PRACK at step 9)

media-type

application/sdp

Content-Length

value

length of message-body

Message-body

(present, if message-body was present in PRACK at step 9)

SDP body of the 200 OK 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.

TS 24.229 [7]