ITU-T Q 84 2-1995 Stage 2 Description for Multiparty Supplementary Services Clause 2 - Three-Party Service - General Recommendations on Telephone Switching and Signalling FunctionsDN (.pdf

1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 1 TELECOMMUNICATION (10/95)STANDARDIZATION SECTOROF ITU%.%2!,G0G02%#/-%.$!4)/.3G0G0/.G0G04%,%0(/.%37)4#().G0G0!.$G0G03).!,).telecommunications service: See definition 201 of 2.2/I.112 3.2.3.3 three-way conversation: Communication between all three users a

2、gents, i.e. the served users agent and thetwo remote users agents.2.4 Symbols and abbreviationsFor the purposes of this Recommendation, the following abbreviations apply:3PTY Three-Party ServiceCC Call ControlCCA Call Control AgentFE Functional EntityFEA Functional Entity ActionISDN Integrated Servi

3、ces Digital NetworkLE Local ExchangePTNX Private Telecommunication Network ExchangeSDL Specification and Description LanguageTE Terminal Equipment2.5 DescriptionNot applicable.2.6 Derivation of the functional model2.6.1 Functional model descriptionThe functional model for the 3PTY supplementary serv

4、ice is shown in Figure 2-1.T1124630-90/d01FIGURE 2-1/Q.84Functional modelFE1 FE2 FE3aFE3brbrarbFIGURE 2-1/Q.84.D01 = 3 CM (118%)2.6.2 Description of functional entitiesThe Functional Entities (FEs) required for the 3PTY supplementary service above those of the basic call are: FE1: Served users agent

5、; FE2: 3PTY control entity; FE3: Remote users agent.Recommendation Q.84 (10/95) 32.6.3 Relationship with a basic serviceThe relationship of the 3PTY supplementary service with the basic service is shown in Figure 2-2.T1124640-90/d02FIGURE 2-2/Q.84Relationship with a basic serviceFE1CCACCAFE2CCACCACC

6、CCCCCCFE3aCCAFE3bCCAr1r3rbr3r2r2r2rbrar1r2FIGURE 2-2/Q.84.D02 = 3 CM (118%)2.7 Information flows2.7.1 Information flow diagramsThe information flows for the 3PTY supplementary service are shown in Figures 2-3 to 2-7 for the followingprocedures: Figure 2-3: Begin three-way conversation; Figure 2-4: E

7、nd the three-way conversation; Figure 2-5: Disconnect call by remote user whilst in three-way conversation mode; Figure 2-6: Disconnect call by served user whilst in three-way conversation mode; Figure 2-7: Disconnect entire call by served user whilst in three-way conversation mode.NOTE The informat

8、ion flow diagrams for the clearing of connections are provided in Recommendation Q.71 5.2.7.2 Definition of individual information flows2.7.2.1 Relationship raThe contents of the information flows (see Figures 2-3 and 2-4) via relationship raand specific to the 3PTYsupplementary service are given in

9、 the subclauses below.2.7.2.1.1 Contents of 3-WAY STARTThis confirmed information flow initiates the bridging of the two calls into a three-way conversation mode, the requestshall be sent in the context of the held call.There are no contents of the 3-WAY START information flow.4 Recommendation Q.84

10、(10/95)T1167230-94/d03920921922926928929929931931910910912rarbrbFE3aFE1 FE2 FE3breq.3-WAY STARTreq.ind3-WAY STARTresp.confINFORM1req.indINFORM1ind.ind.INFORM1conf.INFORM1req.ind3-WAYSTART3-WAYSTARTFIGURE 2-3/Q.84Begin three-way conversationFIGURE 2-3/Q.84.D03 = 3 CM (118%)Recommendation Q.84 (10/95)

11、 5T1167240-94/d04FE1 FE2 FE3a FE3b911911914911927923929929924929929933932932934req.3-WAYENDconf.3-WAY ENDreq.ind3-WAY ENDresp.confINFORM3req.indINFORM2req.indINFORM3ind.INFORM2req.indINFORM3req.indINFORM2ind.INFORM2ind.INFORM3ind.3-WAY ENDNOTE This figure shows the scenario where FE3a is considered

12、as the user agent with the held connection, FE3b is considered as the user agent with the active connection. FE3a is (in this figure) explicitly chosen to have a private communication with the served users agent FE1.FIGURE 2-4a/Q.84Create private communication (case a)rbrbraFIGURE 2-4a/Q.84.D04 = 3

13、CM (118%)6 Recommendation Q.84 (10/95)T1167250-94/d05FE1 FE2 FE3a FE3bconf.req.911 3-WAY ENDreq.ind3-WAY ENDresp.conf927923929929INFORM4req.ind934 INFORM4ind. 932INFORM2req.indINFORM2ind. 9113-WAY ENDNOTE This figure shows the scenario where FE3a is considered as the user agent with the held connect

14、ion FE3b is considered as the user agent with the active connection. FE3b is (in this figure) explicitly chosen to have a private communication with the served users agent FE1.FIGURE 2-4b/Q.84Create private communication (case b)rbrb3-WAYENDraFIGURE 2-4b/Q.84.D05 = 3 CM (118%)Recommendation Q.84 (10

15、/95) 7T1167260-94/d06FE1 FE2 FE3a FE3bDISCONNECT913915927923929925929421 RELEASEreq.indreq.indINFORM3INFORM2req.indreq.indINFORM3ind.(Note)INFORM2ind.932933rbrbraNOTE INFORM3 req.ind is only sent in the case where a held connection between the served user and the remote user still exists.FIGURE 2-5/

16、Q.84Disconnect call by remote user whilst in three-way conversation modeFIGURE 2-5/Q.84.D06 = 3 CM (118%)8 Recommendation Q.84 (10/95)T1167270-94/d07FE1 FE2 FE3a FE3brarbrbDISCONNECT 321req.ind927923929925929915INFORM3req.indINFORM2req.ind933932INFORM3ind.INFORM2ind.(Note)NOTE INFORM3 req.ind is onl

17、y sent in the case where a held connection between the served user and the remote user still exists.FIGURE 2-6/Q.84Disconnect (call FE1-FE3a) call by served user whilst in three-way conversation modeFIGURE 2-6/Q.84.D07 = 3 CM (118%)Recommendation Q.84 (10/95) 9T1167280-94/d08FE1 FE2 FE3a FE3bDISCONN

18、ECT 321req.indDISCONNECT 321req.ind927923929929INFORM3req.ind 933req.indINFORM3ind.INFORM2932(Note 2)INFORM2ind.(Note 1)rarbrbNOTES1 INFORM2 req.ind is sent to the user agent with the active connection in case the held connection has been cleared first.2 INFORM3 req.ind is sent to the user agent wit

19、h the held connection in case the active connection has been cleared first. FIGURE 2-7/Q.84Disconnect entire call by served user whilst in three-way conversation modeFIGURE 2-7/Q.84.D08 = 3 CM (118%)2.7.2.1.2 Contents of 3-WAY START REJECTTable 2-1 shows the contents of the 3-WAY START REJECT inform

20、ation flow.TABLE 2-1/Q.84Contents of 3-WAY START REJECT information flow2.7.2.1.3 Contents of 3-WAY ENDThe confirmed information flow initiates the termination of the three-way conversation mode.There are no contents of the 3-WAY END information flow.Parameter req.indReject reason Mandatory10 Recomm

21、endation Q.84 (10/95)2.7.2.2 Relationship rbINFORM1 shall be used to inform the two remote parties that a three-way conversation has been established.INFORM2 shall be used to inform the remote party that the three-way conversation has been released and a single callexists between served user and the

22、 one remote party.INFORM3 shall be used to inform the remote party that a single held connection exists between the served user and theone remote party.INFORM4 shall be used to inform the remote party that the conference has been disconnected and that a held call existsbetween the served user and th

23、e one remote user.There are no contents of the INFORM1, INFORM2, INFORM3 and INFORM4 information flows.2.8 SDL diagrams for functional entitiesThe Specification and Description Language (SDL) diagrams are provided according to Recommendation Z.100 5.2.8.1 FE1The SDL diagrams for FE1 are shown in Fig

24、ure 2-8.Recommendation Q.84 (10/95) 11T1167290-94/d09FIGURE 2-8/Q.84 (sheet 1 of 5)SDL diagrams for FE1FEA 910IdleProcess 3PTY_FE13-WAY STARTreq.ind3-WAY STARTreq.s2_f8.1(5)FEA 910user3-Way StartPendingraFIGURE 2-8/Q.84 (sheet 1 of 5) .D09 = 3 CM (118%)12 Recommendation Q.84 (10/95)T1167300-94/d10FI

25、GURE 2-8/Q.84 (sheet 2 of 5)SDL diagrams for FE1FEA 9103-WayConversation ActiveIdleFEA 910FEA 913Process 3PTY_FE1s2_f8.2(5)3-Way StartPending3-WAY STARTresp.conf3-WAY STARTREJECTreq.indFEA 910user3-WAY STARTREJECTind.3-WAY STARTconf.FEA 910userBasic callreleaseraraFIGURE 2-8/Q.84 (sheet 2 of 5) .D10

26、 = 3 CM (118%)Recommendation Q.84 (10/95) 13T1167310-94/d11FIGURE 2-8/Q.84 (sheet 3 of 5)SDL diagrams for FE1FEA 913IdleFEA 915Process 3PTY_FE1 s2_f8.3(5)3-WAY ENDreq.ind3-WayConversationActiveFEA 911userBasic callrelease“place remainingcall in the correctheld state”3-WAY ENDreq.3-Way EndPendingraFI

27、GURE 2-8/Q.84 (sheet 3 of 5) .D11 = 3 CM (118%)14 Recommendation Q.84 (10/95)T1167320-94/d12FIGURE 2-8/Q.84 (sheet 4 of 5)SDL diagrams for FE1IdleFEA 914IdleFEA 913Process 3PTY_FE13-WAY ENDconf.FEA 911users2_f8.4(5)3-Way EndPending3-WAY ENDresp.conf“place both callsin the correctheld states”Basic ca

28、llreleaseraFIGURE 2-8/Q.84 (sheet 4 of 5) .D12 = 3 CM (118%)Recommendation Q.84 (10/95) 15T1167330-94/d13FIGURE 2-8/Q.84 (sheet 5 of 5)SDL diagrams for FE1NOTE This breaks the basic call CCA functionality at the following points: for 3PTY1 and 3PTY2, in Figure 2-13/Q.71 4 (sheet 2 of 5), in state “A

29、WAIT RELEASE CONF (0)” following the input “RELEASE resp.conf ” (see FEA413); for 3PTY3 and 3PTY4, in Figure 2-13/Q.71 4 (sheet 3 of 5), in state “AWAIT RELEASE (0)” following the input “RELEASE req.ind” (see FEA312); for 3PTY5 and 3PTY6, in Figure 2-13/Q.71 4 (sheet 3 of 5), in state “AWAIT USER DI

30、SCONNECT (0)” following the input “DISCONNECT req”; for 3PTY7 and 3PTY8, in Figure 2-17/Q.71 4 (sheet 2 of 4), in state “AWAIT RELEASE (T)” following the input “RELEASE req.ind” (see FEA452); for 3PTY9 and 3PTY10, in Figure 2-17/Q.71 4 (sheet 3 of 4), in state “AWAIT USER DISCON (T)” following the i

31、nput “DISCONNECT req”; for 3PTY11 and 3PTY12, in Figure 2-17/Q.71 4 (sheet 4 of 4), in state “AWAIT RELEASE CONF (T)” following the input “RELEASE resp.conf”(see FEA353).1Note2Note56NoteNote910NoteNote34781112NoteNoteNoteNoteNoteNoteProcess 3PTY_FE1 s2_f8.5(5)Basic callreleaseBasic callreleaseBasic

32、callreleaseBasic callreleaseBasic callreleaseBasic callreleaseFIGURE 2-8/Q.84 (sheet 5 of 5) .D13 = 3 CM (118%)16 Recommendation Q.84 (10/95)2.8.2 FE2The SDL diagrams for FE2 are shown in Figure 2-9.T1167340-94/14FIGURE 2-9/Q.84 (sheet 1 of 3)SDL diagrams for FE2Process 3PTY_FE2IdleNoYesNoYesNoYessu

33、bscribed?FEA 920FEA 920FEA 921FEA 922FEA 920FEA 921FEA 920NoYesFEA 922FEA 926-FEA 928s2_f9.1(3)3-way STARTresp.conf3-WAY STARTreq.ind“Interactioncheck?”“3-waybridgeavailable”“connect calls to3_way bridge”INFORM1req.ind3-wayConversationActivereason =“not subscribed”reason = “wrong states”reason =“int

34、eraction error ”reason =“no resources”3-WAY STARTREJECT req.to FE3aand FE3brarara“is 3PTYinvocationpermitted?”r ,bFIGURE 2-9/Q.84 (sheet 1 of 3) .D14 = 3 CM (118%)Recommendation Q.84 (10/95) 17T1167350-94/15FIGURE 2-9/Q.84 (sheet 2 of 3)SDL diagrams for FE2FEA 928FEA 927FEA 923FEA 927FEA 923NoYesNoY

35、esFEA 925FEA 924IdleProcess 3PTY_FE2 s2_f9.2(3)3-WayConversationActive“remove callsfrom 3-way bridge”3-WAY ENDreq.ind“remove calls from3-way bridge”“release 3-wayconversationresources”3-WAY ENDresp.confBasic callrelease“heldconnectionchosen?”“remainingFE3 held”INFORM3req.indINFORM3req.ind“place rema

36、iningcall in the correctheld state”INFORM2req.ind“place both calls inthe correct heldstates”INFORM4req.indINFORM2req.indINFORM3req.indINFORM2req.indINFORM2req.indrara“release 3-wayconversationresources”r , to held FE3bFEA 929r , to held FE3br , to active FE3bFEA 929r , to held FE3bFEA 929r , to acti

37、ve FE3bFEA 929r , to now held FE3b to remaining FE3FEA 929r , to now active FE3bFIGURE 2-9/Q.84 (sheet 2 of 3) .D15 = 3 CM (118%)18 Recommendation Q.84 (10/95)T1167360-94/d16FIGURE 2-9/Q.84 (sheet 3 of 3)SDL diagrams for FE231NOTE This breaks the basic call CC functionality at the following points:

38、for 3PTY13 and 3PTY14, in Figure 2-14/Q.71 4 (sheet 5 of 7), in state “r -REL (F)” following the input “RELEASEresp.conf.” from r (see FEA322); for 3PTY15 and 3PTY16, in Figure 2-14/Q.71 4 (sheet 5 of 7 ), in state “r - REL (B)” following the input “RELEASEresp.conf ” (see FFA322); for 3PTY17 and 3P

39、TY18, in Figure 2-14/Q.71 4 (sheet 5 of 7), in state “r -DISCON (B)”preceding the output “RELEASE resp.conf” to r in the transition commenced by input “RELEASE req.ind” (see FEA422); for 3PTY19 and 3PTY20, in Figure 2-16/Q.71 4 (sheet 4 of 5), in state “r -REL (B)” following the input “RELEASE esp.c

40、onf ” from r (see FFA442); for 3PTY21 and 3PTY22, in Figure 2-16/Q.71 4 (sheet 5 of 5), in state “r -REL (F)” following the input “RELEASE esp.conf ” (see FEA442); for 3PTY23 and 3PTY24, in Figure 2-16/Q.71 4 (sheet 5 of 5 ), in state “r -DISCON (F)” preceding the output “RELEASE resp.conf” to r in

41、the transition commenced by input “RELEASE req.ind” (see FFA342).21123111131417182122NoteNoteNoteNoteNoteNote151619202324NoteNoteNote NoteNoteNoteProcess 3PTY_FE2Basic callreleaseBasic callreleaseBasic callreleaseBasic callreleaseBasic callreleaseBasic callreleaseFIGURE 2-9/Q.84 (sheet 3 of 3) .D16

42、= 3 CM (118%)Recommendation Q.84 (10/95) 192.8.3 FE3a and FE3bThe SDL diagrams for FE3a and FE3b are shown in Figure 2-10.T1167370-94/d17FIGURE 2-10/Q.84SDL diagram for FE3a and FE3bIdleFEA 931user-Process 3PTY_FE3INFORM1req.indINFORM2req.indINFORM4ind.FEA 934userINFORM3req.indINFORM4req.indINFORM3i

43、nd.FEA 9333userINFORM1ind.FEA 932userINFORM2ind.FEA 931rbFEA 934rbFEA 933rbFEA 932rbFIGURE 2-10/Q.84 .D17 = 3 CM (118%)20 Recommendation Q.84 (10/95)2.9 Functional entity actions (FEAs)2.9.1 FEAs of FE1910: The functional entity shall: recognize a user request for 3-WAY START req.; generate and tran

44、sfer a 3-WAY START req.ind to FE2 or reject the user request if not valid; recognize a 3-WAY START resp.conf from FE2; transfer a service confirmation towards the user.911: The functional entity shall: recognize a user for 3-WAY END req.; generate and transfer a 3-WAY END req.ind to FE2; recognize a

45、 3-WAY END resp.conf from FE2; transfer a service confirmation towards the user.912: The functional entity shall check the states of the two calls involved.913: The functional entity shall recognize a remote or local clearing request of either one of the calls or theentire 3-way conversation call.91

46、4: The functional entity shall place both connections in the correct held states.915: The functional entity shall place the remaining connection in the correct held state.2.9.2 FEAs of FE2920: The functional entity shall: recognize a 3-WAY START req.ind from FE1; check for a valid start condition.92

47、1: The functional entity shall: check for unauthorized interaction with other supplementary services (e.g. interaction with CONFsupplementary service); check for authorized interaction with other supplementary services (e.g. matching of CUG-information).922: The functional entity shall seize resourc

48、es (e.g. three-way bridge).923: The functional entity shall release resources (e.g. three-way bridge).924: The functional entity shall place both connections in the correct held states.925: The functional entity shall place the remaining connection in the correct held state.926: The functional entit

49、y shall connect the two calls to the bridge.927: The functional entity shall remove the two calls from the bridge.928: The functional entity shall control interaction with other supplementary services whilst in the 3-Wayconversation Active state.929: The functional entity shall notify the remote users of either the establishment or clearing of a three-wayconversation, and/or the occurrence of one single h