ITU-T Q 85 3-1992 STAGE 2 DESCRIPTION FOR COMMUNITY OF INTEREST SUPPLEMENTARY SERVICES SECTION 3 - MULTI-LEVEL PRECEDENCE AND PREEMPTION (MLPP) (rev 1) (Study Group XI)《共同利益补充性业务的第.pdf

1、INTERNATIONAL TELECOMMUNICATION UNION#)44 1 THE INTERNATIONALTELEGRAPH AND TELEPHONECONSULTATIVE COMMITTEEr , FE4 towards another CUG domain.a ya yNote 2 This INFORM 2 req. ind. shall be sent simultaneously with the basic call SETUP req. ind.Notes relative to Figure 1-10/Q.85 (sheet 1 of 2):T1125790

2、-90CUG9923CUG10INFORM 2REJECTreq. ind.Insert reject reasoninto basic callclearing informationflowsYesNo924(Note 2)924FE4, r(Note 1)CUGsupplementaryservice explicitlyrequested by theuser?Note 1 Information processed simultaneously with the basic call clearing information flows.Note 2 FE1, r towards a

3、 user end equipment FE4, r towards another CUG domain. This information flow shall besent simultaneously with the basic call clearing information flow.FIGURE 1-10/Q.85 (sheet 2 of 2)CUG, FE2bayINFORM 1REJECTreq. ind.Note 3 CUG9 and CUG10 are hooks at the receipt of basic call clearing information fl

4、ows at outgoing calls prior tothe receipt of SETUP resp. conf., they break the basic call between connectors S2/35 and S2/36, S2/37 and S2/38 ofRecommendation Q.71 4. CUG9 and CUG10 additionally are hooks in CC FE2 call state r -r CALL SENT followingthe receipt of RELEASE req. ind. (see Recommendati

5、on Q.71 4, Figure A-2/Q.71). On a call received from an otherCUG domain of a private ISDN, CUG9 and CUG10 break accordingly (see Figures 2-18 CC FE6, sheet 2 of 7, sheet 3of 7, sheet 7 of 7 of Recommendation Q.71 4).1216 Recommendation Q.85T11255800-90r , FE2930OKr , FE2 r , FE2dddIDLEPerform outgoi

6、ngCUG controlENQUIRY 1req. ind.Results?ENQUIRY 1resp. conf.(REJECTREASON)ENQUIRY 1resp. conf.(“OK”)FIGURE 1-11/Q.85CUG, FE3IDLEIDLERejectRecommendation Q.85 17T1131450-90r , FE2940CUG12CUG11940 CUG13FE5, rFE5,r941r , FE2943CUG14 CUG13NoYesINFORM 2req. ind.ENQUIRY 2req. ind.WAITENQUIRYTIMERTCUG1ENQUI

7、RY 2resp. conf.(REJECTREASON)ENQUIRY 2conf. resp.(“OK”)Reset(Timer TCUG1)INFORM 2REJECTreq. ind.INFORM 1req. ind.(Note 2)SET REJECTREASON = SERVICENOT AVAILABLEbeycbeeFE5, r941There are threecases non IC CUG index, asa national option:CUG index + OAindication942r , FE2 towardsanother CUGdomainr , FE

8、6 towardsan end userequipmentDoesthe called userhave the CUGfacility?FIGURE 1-12/Q.85 (sheet 1 of 2)CUG, FE4Reset(Timer TCUG1)SET (NOW +WAITING TIME,TIMER TCUG1)(Note 1)18 Recommendation Q.85Note 3 CUG11, CUG12, CUG13 and CUG14 break the basic call on a call towards a user end equipment between conn

9、ector S4/31and S4/32 of Recommendation Q.71 4. On a call towards another CUG domain of a private ISDN, CUG11, CUG12, CUG13 andCUG14 break the basic call during CC state “IDLE” during FEA271 (see Figure 2-19/Q.71 4). “Terminating screening, processattempt” prior to sending SETUP req. ind. (FEA271).Th

10、e analysis of MSN and DDI shall be performed prior to invocation of CUG. The CUG specific checks shall be performed prior tothe determination of network determined user busy.CUG13 is the exit to proceed with the call CUG14 is the exit where the call shall be cleared: this is the same exit as the NO-

11、branchof the preceeding decision “successful” of Recommendation Q.71 4.Note 1 Timer TCUG1 shall be implemented in the case of the remote data base. TCUG1 shall be automatically reset by basic call atany event resulting in clearing the call relation.Note 2 This INFORM 1 req. ind. shall be sent simult

12、aneously with the basic call SETUP req. ind.Notes relative to Figure 1-12/Q.85 (sheet 1 of 2):T1125820-90CUG15CUG16FE2, r944FE2, rbyINFORM 1REJECTreq. ind.Note This information flow is processed simultaneously with the basic call clearing information flow. On a calltowards another CUG domain of a pr

13、ivate ISDN CUG15 and CUG16 break the basic call transition during any callstate after sending of SETUP req. ind. and prior to receipt of REPORT (ALERTING) or SETUP resp. conf. (if noalerting occurs). See Figure 2-19/Q.71 of Recommendation Q.71 4.FIGURE 1-12/Q.85 (sheet 2 of 2)CUG, FE4INFORM 2REJECTr

14、eq. ind.Recommendation Q.85 19T1125830-90FE4, r950FE4, rFE4, rOKeeeIDLERejectENQUIRY 2req. ind.Performincoming CUGcontrolENQUIRY 2(REJECTREASON)resp. conf.ENQUIRY 2resp. conf.“OK”Results?FIGURE 1-13/Q.85CUG, FE5IDLE IDLE1.9 Functional entity actions (FEAs)1.9.1 FEAs of FE1910: The functional entity

15、shall receive CUG request from the user and transfer the requestsimultaneously with the call setup request.911: The functional entity shall recognize CUG specific reject reasons and indicate the reason to its user.1.9.2 FEAs of FE2920: The functional entity shall: identify a CUG call; check the CUG

16、subscription of the calling user; access the outgoing CUG control entity (FE3).20 Recommendation Q.85921: The functional entity shall receive the results of the CUG specific checks from the outgoing CUGcontrol entity (FE3).922: The functional entity shall: store the CUG characteristics as received f

17、rom FE3; transfer the CUG request simultaneously with the basic call setup request as received from FE3.923: The functional entity shall insert the reject reason into basic call clearing information flow element“cause”.924: The functional entity shall transfer simultaneously with basic call control

18、clearing information flow INFORM 1 REJECT with CUG specific reasons.T1125840-90CUG17CUG18UserINFORM 1req. ind.(Note 1)INFORM 1 ind.(Notes 1and 2)960FE4, r(Notes1 and 2)Note 1 This is received/sent simultaneously with the basic call SETUP req. ind.Note 2 CUG17 and CUG18 break the basic call between c

19、onnector S5/1 and S5/2 (see Recommen-dation Q.71 4).FIGURE 1-14/Q.85CUG, FE6c1.9.3 FEAs of FE3930: The functional entity shall: perform validation checks of CUG information of a calling user according to Table 1-9/Q.85; convert the CUG index to an interlock code.Recommendation Q.85 21TABLE 1-9/Q.85C

20、UG interpretation table (outgoing side)a)In case of OCB (CUG), a call is rejected.The combination of PCUG and OCB with the PCUG is barred in the option data.b)In case of OCB (CUG), a call is interpreted as an ordinary call.c)Both “preferential CUG” and “implicit” outgoing access options imply that n

21、o subscriber procedures are needed toinvoke either of the options when placing a call. When a user subscribes to both options, the network does not knowwhich option the user is invoking, if no additional subscriber procedures are used when placing the call.Three ways of operating are recommended:1)

22、the user has to indicate if a call is intended to be an outgoing access call. If no information (CUG request or outgoing callrequest) is given, the preferential CUG is assumed;2) the combination is not allowed, i.e. a user cannot have both options allocated at the same time;3) the caller may make a

23、call and the network will route the call with the preferential CUG and an outgoing access request.The call will therefore be connected if the called number is a member of the preferential CUG or is a member of adifferent CUG and has incoming access, or is a non-CUG user.In the case of the first way

24、of operating, CUG interpretation is “PCUG”. In the case of OCB, Note a) is applicable.In the case of the second way of operating, the combination of the options is not allowed.In the case of the third way of operating, CUG interpretation is “PCUG with OA”. In the case of OCB, Note a) isapplicable.Th

25、e choice from the above cases is a national option.OA(E) Outgoing access explicitIf the “allowed per call (explicit OA)” outgoing access option is assigned then the CUG user can determine the OAstatus by means of the OA request on a call by call basis, but if the “allowed per call” outgoing access o

26、ption is notassigned then the OA request shall be ignored by the network and the OA status shall be determined according tothe OA subscription option.OA(I) Outgoing access implicitOA Outgoing access allowedOCB Outgoing access barred within the CUGPCUG Preferential CUGNote 1 When an illegal index cod

27、e is received, the outgoing call is rejected.Note 2 All the user classes are not necessarily supported by all the networks. User classes to be supported are networkdependent.SETUPpresentationCalling user classCUG withindexOA = OFFCUGwith indexOA = ONCUGwithout indexOA = OFFCUGwithoutindexOA = ONNon-

28、CUGinformationCUGCUG+OA(E)CUG+OA(I)PCUGYes SpecifiedCUG a)SpecifiedCUG a)Rejected Rejected RejectledYes SpecifiedCUG a)SpecifiedCUG b)Rejected OrdinarycallOrdinary callYes SpecifiedCUG b)SpecifiedCUG b)Ordinary call OrdinarycallOrdinary callYes Yes SpecifiedCUG a)SpecifiedCUG a)PCUG a)Rejected PCUG

29、a)FE3Yes Yes SpecifiedCUG a)SpecifiedCUG b)PCUG a)OrdinarycallPCUG a)Yes Yes SpecifiedCUG b)SpecifiedCUG b)c)Ma)Ordinarycall c)Ma)c)Ma)Calling user is NOT CUG REJECT Ordinary call FE222 Recommendation Q.851.9.4 FEAs of FE4940: The functional entity shall: identify a call for a user with CUG service;

30、 access the incoming CUG control entity (FE5).941: The functional entity shall receive the results of the CUG specific checks from the incoming CUGcontrol entity.942: The functional entity shall: store the CUG characteristics as received from FE5; transfer the CUG request as received from FE5 simult

31、aneously with the basic call setup request.943: The functional entity shall transfer simultaneously with basic call clearing information flowINFORM 2 REJECT with CUG specific reasons.944: The functional entity shall, in the case of a call towards a PN FE2, provide the capability to receivea CUG-spec

32、ific rejection of the call from the PN. In this case the requirement is to receive andtransfer simultaneously with basic call control information flow CUG specific INFORM 1 REJECTwith CUG specific reason.1.9.5 FEAs of FE5950: The functional entity shall, according to Table 1-10/Q.85: converse the in

33、terlock code to CUG index; perform validation checks of CUG information of a called user (including the compatibility with thecalled user class CUG IA in case of ordinary incoming call).1.9.6 FEAs of FE6960: The functional entity shall receive CUG indication simultaneously with the call SETUP req. i

34、nd.and indicating this to the user.Recommendation Q.85 23TABLE 1-10/Q.85CUG checking in incoming sidea)Covered by SDLsIA Incoming accessOA Outgoing accessNote 1 Since CUG OA user class is not concerned in the incoming case, it is not shown in the above list. Itshall be regarded that CUG OA user clas

35、s is the same as user class CUG, and CUG OA/IA is the same as userclass CUG IA in this table.Most of the table is performed in FE5.Note 2 (1)-(3) shows CUG parameter to be used in the SETUP to the called user.(1) CUG index;(2) CUG + OA (index + OA mark), this is a national option;(3) No CUG (ordinar

36、y call).Note 3 ICB means incoming calls barred within the CUG. The interpretation logic is changed in this case asshown in each column in the table. For example:This means that when the interlock codes are matched and no ICB is applied for the CUG, then (1) is used.However, when ICB is applied for t

37、he CUG, the incoming call is rejected even if interlock codes are matched.Note 4 M means that the interlock code is matched with the CUG of the called user.Note 5 NM means “not matched”.Note 6 REJ means that an incoming call is rejected.Note 7 Interpretation logic, e.g.:means that when matched with

38、CUG, no CUG selection facility field is set in the SETUP to the called user.Note 8 This may be supported as a national option.Called usersclassCalled user is CUGSEPUPCUG with orwithout PCUGCUG IA with orwithout PCUGCalled user is notCUGPresentationNo ICB ICB No ICB ICBCUGM (1) REJ M (1) REJREJNM REJ

39、 NM REJCUG and OA(Note 8)M (1) REJ M (2) 3(3)NM REJ NM (3)Ordinary REJ (3) (3) a)No ICB ICBM (1) REJM(3)24 Recommendation Q.851.10 Allocation of functional entities to physical locationsTABLE 1-11/Q.85DB Data base.IIC Incoming international centre.LE Local exchange.OIC Outgoing international centre.

40、TE Terminal equipment.Note The symbol “ however, it does define which functional entities may be allocated to a private ISDN.This Recommendation does not specify the additional requirements where the service is provided to the uservia a telecommunication network that is not an ISDN.This Recommendati

41、on is applicable to the stage 3 Recommendations for the ISDN MLPP supplementaryservice. The term “stage 3” is defined in Recommendation I.130 1.3.2 ReferencesThese following references are applicable:1 CCITT Rec. I.130 Method for the characterization of telecommunication services supported by an ISD

42、N andnetwork capabilities of an ISDN, 19882 CCITT Rec. Q.65 Stage 2 of the method for the characterization of services supported by an ISDN, 1988.3 CCITT Rec. Q.711)ISDN 64 kbit/s circuit mode switched bearer services, 1993.4 CCITT Rec. I.210 Principles of telecommunication services supported by an

43、ISDN and the means to describethem, 1988.5 CCITT Rec. I.255.3 Multi-Level Precedence and Preemption service (MLPP), 1990.3.3 DefinitionsFor the purpose of this Recommendation, the following definitions apply:MLPP callA call that has a precedence level established and is either being setup or is setu

44、p. Only MLPP subscriberscan generate MLPP calls, which are identified by a precedence level. Calls from non-MLPP subscribers will not carry aprecedence level and shall not be preempted.preemptable circuitA circuit that is active with or reserved for an MLPP call:1) within the same domain as the pree

45、mpting call; and2) with a lower precedence than the preempting call. A busy or reserved circuit for which a precedencelevel has not been specified is not a preemptable circuit._1)Recommendation Q.71 will be submitted for approval at the CCITT Plenary Assembly in March, 1993.26 Recommendation Q.85pre

46、cedence callA call with precedence level higher than the lowest level of precedence.users A and BParties of the MLPP call A-B for scenarios involving preemption in the network. User A is also a party of theMLPP call A-D for scenarios depicting preemption in the user access area.user CCalling party o

47、f the preempting higher precedence call.user DCalled party of the preempting higher precedence call from user C. User D is also a party of the MLPP call A-D for preemption in the user access area scenarios.LFB req. ind.An optional information flow used to find out whether network resources are avail

48、able to support the higherprecedence call. Available resources include ideal circuits and circuits used for lower precedence calls. Thisinformation flow will provide call path reservation.LFB resp. conf.The response information flow used to indicate the status of the called party and network resourc

49、es. Possibleresponses are: available and unavailable. Available means that network and called party resources are available tosupport the higher precedence call. The called party is available if it is either:1) not busy;2) busy with a call of lower precedence with preemptable access resources;3) busy with a call of equal or higher precedence with call; completion or call offering services(i.e. Call Waiting or Call Forwarding Busy) or an alternate party, or4) busy with access resource