Detailed Analysis of Intelligent Network Application Part (INAP) Messages In Accordance with ITU-T INAP Message Definitions

Pre requisitesThe report is specific to INAP message analysis and does not elaborate on the overall CCS No. 7 Signaling. Therefore, prior knowledge of the CCS No. 7

Signaling protocol stack, its functions, basic structure of an Intelligent Network and its functional entity description is a pre requisite.

Brief IntroductionIntelligent Network: The Intelligent Network (IN) concentrates the intelligence for controlling telecommunications services in a small number of IN switches instead of spreading it throughout the network, making it possible to introduce new services faster and independently of the switch vendors. The Service Switching Point (SSP) allows the users access to the IN capabilities. The SSP contains a normal switch call control function (CCF) and a service switching function (SSF) that provides the interaction with the Service Control Point (SCP). The SCP contains the service logic programs via the service control function (SCF) that handle the IN service processing and data via the service data function (SDF) in the SDP. The intelligent peripheral (IP) provides the special resources needed for supporting the IN services via the specialized resource function (SRF). Intelligent Network Application Part (INAP): The Intelligent Network Application Part (INAP) is part of the Common Channel Signaling No. 7 protocol stack and is used to communicate between the functional entities SCF, SSF, SRF and SDF. INAP is a communication protocol in application layer, the same as HTTP or FTP. The ITU-T recommendations on INAP are included in Q.1218 and Q.1228, detailing on and defining the information flows between the functional entities mentioned above. Moreover, it defines the operation procedures after each functional entity (FE) has received the information. This report details the specific correlation between the theoretical (ITU-T recommended) INAP message pattern and the practical call flow implementation in the Huawei- FIN. INAP is a user of the TCAP layer and therefore the TCAP messages are analyzed on the SSP end as well. The following call flow message pattern is of a successful Prepaid Calling Card Service (PPS) call.

1- TC_Begin (SSP to SCP):TC_Begin (TCAP) message is to request or indicate to begin a dialogue. Dialogue is the association established between two TC users exchanging data. The message at SSP end is analyzed as follows:

TCAP Message from SSP to SCP Message length :1F 00 -- Length of current message transfer. Primitive type :TC_BEGIN_REQ -- In SS7 system, the information exchange between two adjacent layers is called primitive. TC_Begin being used to request a dialogue. User Part :INAP -- INAP being the user of the TCAP message Direction :[User->TCAP] -- Indicates the direction from SSP to SCP QOS present:01 -- Quality of Service presence indicated. Network indicator :02 -- National Network Indicated Original Signal Point code :E6 14 00 00 -- 0x14E6 SPC of SSP Dialog ID :66 0E 00 00 -- ID assigned for all subsequent message transfers of the dialog. All data transmission in Hexadecimal format. -- Original Address Indication Route flag :Route on SSN -- Routing indicated to use Sub System Number + DPC rather than GT GT indicator :no -- No global title included SSN indicator: address contains a subsystem number DPC indicator :address contains a signaling point code DPC :14 E6 SSN indicator :INAP(Intelligent Network Application) -- Destination Address Indication GT indicator :no global title included SSN indicator :address contains a subsystem number DPC indicator :address contains a signaling point code DPC :34 13 -- 0x3413 SPC of SCP SSN indicator :INAP(Intelligent Network Application)

1-

TC_Begin (Received by SCP):

The TC_Begin is received by the SCP. Following is the tracer at SCP end. SSP->SCP ======================== TCBEGIN===============================

originatingAddress: "0x05 43 00 e6 14 0c 00 00 00 00 00 00 00 00 00 00 00 00" Routing indicator : Route On SSN Global title indicator : 0 SSN indicator :1 Point code indicator : 1

(14E6 SPC of SSP)

(SSN + DPC Used)

Signalling Point Code : 0x00E614 Subsystem Number : 0x0C (Sub System Number Allotted for the dialogue) Global Title : Not Present destinationAddress: "0x05 43 00 13 34 0c 00 00 00 00 00 00 00 00 00 00 00 00" Routing indicator : Route On SSN Global title indicator : 0 SSN indicator :1 Point code indicator : 1 (3413 SPC of SCP)

(SSN + DPC Used)

Signalling Point Code : 0x001334 Subsystem Number : 0x0C (Sub System Number Allotted for the dialogue) Global Title : Not Present dialogueID : 185413 (Same dialogue ID as initiated by SSP)

2-

TC_Invoke (SSP to SCP):

Invoke (TCAP) message is used to send an operation request to remote TC-User. INAP Message transported : IDP TCAP Message from SSP to SCP Primitive type :TC_INVOKE_REQ -- Invoke is used to send an operation request to remote TC-User. User Part :INAP -- INAP being the user of the TCAP message Direction :[User->TCAP] -- Indicates the direction from SSP to SCP Dialog ID :66 0E 00 00 -- ID assigned for all subsequent message transfers of the dialog. All data transmission in Hexadecimal format.

Timeout length :2C 01 -- Time out set for the message reply from the SCP Initial Detection Point (IDP) (INAP Message, initiated in SSP): IDP is the first INAP message sent from SSP to SCP for an IN call. This operation is used to prompt the request of an IN service after a trigger detection point (TDP) at SSP. The parameters included in IDP are the access code of the service, service key, caller number, called number, number attributes and so on. It is transported through the TC_Invoke message to the SCP. INAP Message from SSP to SCP InitialDP Service Key ServiceKey :00 C8 (0xc8 = 200 PPS) Called Party Number nature of address indicator :subscriber number (NADI = Subsrciber) numbering plan indicator :ISDN/telephony numbering plan Called party number :1010 Calling Party Number nature of address indicator :subscriber number (NADI = Subsrciber) number incomplete indicator: number complete (Complete Number Identified) numbering plan indicator :ISDN/telephony numbering plan Calling party number :0513123458 Calling Party Category CallingPartyCategory :test call Encoding standard: ITU-T standardized coding (ITU-T Speech specifications) Information transfer capability: Speech Transfer mode: Circuit mode Information transfer rate :for circuit mode,64kb/s Event Type BCSM (Basic Call State Model) Event type BCSM: Analyzed Information

2- TC_Invoke (Received in SCP):The SCP receives TC_Invoke. The IDP (Received INAP Message) is inside the TC_Invoke. ========================= TCINVOKE============================= DialogueID: 185413 | Operation: INAP_InitialDP (The SCP receives the INAP message IDP in this TC Message.) ============================================== ================== [TiINAPInitialDPArg] serviceKey=200 (PPS Call Flow to be activated) calledPartyNumber="1010" callingPartyNumber="0513123458" eventTypeBCSM=analyzedInformation

3- TC_Invoke (SCP to SSP):The INAP Message (RRBCSME) transported through this TC Message. Message invoked by the SCP to request the SSP to report the BCSM Event. Request Report BCSM Event (RRBCSME) (INAP Message): INAP message RRBCSME is sent from SCP to SSP, requesting SSP to configure DP dynamically. When SSP meets these DPs in later call process, SSP will report call information to SCP. RRBCSME provides SCP the condition of controlling calls. The parameters of RRBE include DP type, DP condition, etc. One RRBCSME can configure several DPs. ========================= TCINVOKE============================= DialogueID: 185413 | operation: INAP_RequestReportBCSMEvent ============================================== ================== [TiINAPRequestReportBCSMEventArg] (INAP Argument to be passed to SSP) bcsmEvents= [0]= eventTypeBCSM=10 (10 = Abandoned Call Event) (If this event takes place (subscriber abandons the call), then SSP should interrupt flow by instigating Event Detection Point and passing control to SCP)

monitorMode=0 (Monitor Mode = Interrupt Call Flow in case of Abandoned Event)

TC_Invoke (Received by SSP): The above argument of instructing SSP to report an abandoned event to SCP is received by SSP.3-

Message length :1B 00 Primitive type :TC_INVOKE_IND User Part :INAP Reserved :00 Direction :[TCAP->User] Dialog ID :66 0E 00 00 RequestReportBCSMEvent (RRBE) INAP Message (Received by SSP): RequestReportBCSMEvent Event type BCSM:oAbandon (Abandon Event is to be reported to SCP) Mnitor Mode Monitor mode:interrupted (Call flow is to be interrupted if such an event occurs)

4-

TC_Invoke (SCP to SSP):

INAP Message transported is ConnectToResource (CTR). Message invoked by the SCP to request the SSP to connect the subscriber to an announcement resource (e.g. any SPD 64kbps port), indicating that announcement shall be played shortly. Connect To Resource (CTR) (INAP Message): CTR is sent from SCP to SSP, requesting SSP to connect the user to IP. CTR provides the users the condition of using IP. If IP is integrated with SSP, SSP makes only the internal connection with IP. If IP is independent from SSP, SSP communicates IP via TUP messages, connecting the users to IP through PSTN voice channels. ========================= TCINVOKE============================= dialogueID: 185413 | operation: INAP_ConnectToResource (CTR) ============================================== ================== [TiINAPConnectToResourceArg] (No INAP argument passed to SSP in this case)

resourceAddress= none SSP)

(Because of IP being integrated within

4-

TC_Invoke (Received by SSP):

The INAP Message CTR received by SSP and allocates an SPD port to the subscriber. Primitive type :TC_INVOKE_IND User Part :INAP Reserved :00 Direction :[TCAP->User] ConnectToResource (The INAP message inside the TC Message) ResourceAddress Null

5-

TC_Invoke (SCP to SSP):

The INAP Message PromptAndCollectUserInformation (P&C) is transported. Prompt and Collect User Information (P&C) (INAP Message): P&C is sent from SCP to SSP, requesting IP to play voice prompts to the subscriber and collect the users input. ========================= TCINVOKE============================= dialogueID: 185413 | operation: INAP_PromptAndCollectUserInformation ============================================== ================== [TiINAPPromptAndCollectUserInformationArg] (Arguments to be passed to SSP) collectedInfo= collectedDigits= minimumNbOfDigits=1 (Min Max = 1) maximumNbOfDigits=1 endOfReplyDigit="#" (End of input) cancelDigit="*" (Restarting input) firstDigitTimeOut=20 (Time out before first digit is pressed) interDigitTimeOut=5 (Time out between digits) interruptableAnnInd=TRUE (Interruptible Announcement) messageID=

elementaryMessageID=0x6030028(100859944) (Voice ID = 06030028) (Welcome to Calling Card Service, For instructions in Urdu press1 & for English press2)

5-TC_Invoke (Received by SSP):P&C Received. The SSP then prompts the user with the relevant announcement w.r.t the message ID given by SCP. It will also wait for user response to collect digits. Message length :48 00 Primitive type :TC_INVOKE_IND User Part :INAP Direction : [TCAP->User] Dialog ID :66 0E 00 00 PromptAndCollectUserInformation (The INAP Message Received) CollectedDigits MinimumNbOfDigits:01 (min max = 1) MaximumNbOfDigits:01 EndOfReplyDigit:0C (0c = #) CancelDigit:0B (0b = *) FirstDigitTimeOut:14 (In hexadecimal) InterDigitTimeOut:05 ElementaryMessageID :06 03 00 28 (ID of Announcement to be played by SSP/IP)

6-

TC_Result_L_Req (Initiated by SSP):

TC_Result_L_Req is used to return the result of an operation. Primitive type :TC_RESULT_L_REQ Direction :[User->TCAP] Dialog ID :66 0E 00 00 ReceivedInformation Encoding Scheme :BCD odd: (Odd number of digits) Number :2F (Received digit = 2, F means end of input)

6-TC_Result_L_Req (Received by SCP):========================= TC-RESULTL=========================== dialogueID : 185413 operation : INAP_PromptAndCollectUserInformation ============================================== ================== [TiINAPReceivedInformationArg] digitsResponse="2" (Received digit = 2)

7-

TC_Invoke (SCP to SSP):

INAP Message transported is P&C, to ask the user to enter card number and then collect the digits. ========================= TCINVOKE============================= dialogueID: 185413 | operation: INAP_PromptAndCollectUserInformation ============================================== ================== minimumNbOfDigits=2 (min max = 2-25) maximumNbOfDigits=25 endOfReplyDigit="#" cancelDigit="*" firstDigitTimeOut=20 interDigitTimeOut=5 interruptableAnnInd=TRUE messageID= elementaryMessageID=0x6020001(100794369)(Enter Card No. Announcement)

8- TC-RESULT-L (Result from SSP to SCP):========================= TC-RESULTL=========================== dialogueID : 185413 operation : INAP_PromptAndCollectUserInformation ============================================== ================== [TiINAPReceivedInformationArg] digitsResponse="7777777*****#" (Card No. Collected by SSP and Given to SCP)

9-

TC_Invoke (SCP to SSP):

INAP Message transported is P&C, to prompt the user of his/her card balance, to request to dial desired number and collect the digits. ========================= TCINVOKE============================= dialogueID: 185413 | operation: INAP_PromptAndCollectUserInformation

============================================== ================== minimumNbOfDigits=1 (min max = 2-25) maximumNbOfDigits=25 endOfReplyDigit="#" cancelDigit="*" firstDigitTimeOut=20 interDigitTimeOut=5 messageID= variableMessage= variableParts= [0]= messageID=0x6020022(100794402) (Your balance is .) [1]= price=01 00 91 df (Numerical Value passed to SSP where it calculates which IDs to play for the specific amount) [2]= messageID=0x6020205(100794885) (Prompt to dial the desired number to call)

10- TC-Result-L (Result from SSP to SCP):========================= TC-RESULTL=========================== dialogueID : 185413 invokeID :5 operation : INAP_PromptAndCollectUserInformation lastComponent :1 ============================================== ================== [TiINAPReceivedInformationArg] digitsResponse="03335174444#" (Number Dialed)

11- TC_Invoke (SCP to SSP):INAP Message transported is INAP_PlayAnnouncement. Play Announcement (PA) (INAP Message): PA is sent from SCP to SSP, requesting IP to play voice prompts to the users. PA does not need result return from IP.

========================= TCINVOKE============================= dialogueID: 185413 | operation: INAP_PlayAnnouncement ============================================== ================== [TiINAPPlayAnnouncementArg] messageID= elementaryMessageID=0x6020023(100794403) (Please wait . Announcement to be played)

12- TC_Invoke (SSP to SCP):

INAP_Specialised Resource Report (SRR) transported.

Specialised Resource Report (SRR) (INAP Message): SRR is sent from SSP to SCP, notifying SCP the end of playing announcement. ========================= TCINVOKE============================= dialogueID: 185413 | operationType: 0 | operation:INAP_SpecializedResourceReport ============================================== ================== [TiINAPSpecializedResourceReportArg]NULL (Null Argument passed from SSP to SCP)

13- TC_Invoke (SCP to SSP):

INAP Message transported is P&C, to prompt the user of his/her card balance, ========================= TCINVOKE============================= dialogueID: 185413 | operation: INAP_PromptAndCollectUserInformation ============================================== ================== [TiINAPPromptAndCollectUserInformationArg]

messageID= variableMessage= elementaryMessageID=0x602002a(100794410) (Announcement: You have ..allowed duration for the call) variableParts= [0]= duration=00 00 02 00 (Variable passed to SSP to determine which duration announcements to play)

14- TC_U_Error (SSP to SCP):TC_U_Error is a Request Primitive, which is used to return the error code when the operation fails although TC-User has received the correct operation request. This error should be investigated. ========================== TC-UERROR========================= dialogueID : 185413 invokeID :7 error : INAP_ImproperCallerResponse ============================================== ==================

15- TC_Invoke (SCP to SSP):Disconnect Forward Connection (DFC) is transported. Disconnect Forward Connection (DFC) (INAP Message): DFC is sent from SCP to SSP, requesting SSP to disconnect the connection between the users and IP.

16- TC_Invoke (SCP to SSP):INAP message RequestReportBCSMEvent (RRBCSME) is transported. ========================= TCINVOKE============================= dialogueID: 185413 | operationType: 2 | operation: INAP_RequestReportBCSMEvent ============================================== ================== [TiINAPRequestReportBCSMEventArg] (These bcsm events are configured from SCP to SSP at call setup time so that correct EDPs (Event Detection Points) can be identified in SSP in case of a call being dropped.) bcsmEvents=

[0]= eventTypeBCSM=9 monitorMode=0 legID= sendingSideID="\1" [1]= eventTypeBCSM= monitorMode=0 legID= sendingSideID="\2" [2]= eventTypeBCSM=4 monitorMode=0 [3]= eventTypeBCSM=6 monitorMode=0 dpSpecificCriteria= applicationTimer=60 [4]= eventTypeBCSM=5 monitorMode=0 [5]= eventTypeBCSM=7 monitorMode=1

(9 = Call Disconnected) (Interrupt the call flow in this case) (Calling Party Hooks on) (9 = Call Disconnected) (Interrupt the call flow in this case) (Called Party Hooks on) (4 = Route Selection Failure) (Interrupt the call flow in this case) (6 = No Answer) (Interrupt the call flow in this case) (Time out on 60 seconds) (5 = Called Party Busy) (Interrupt the call flow in this case) (7 = Call Answered) (Notify and Continue)

17- TC_Invoke (SCP to SSP):

INAP message Apply Charge (AC) is transported. Apply Charge (AC) (INAP Message): AC is sent from SCP to SSP, requesting SSP to charge the call. The parameters of AC include: charge class, calling party number, called party number, the balance of the subscriber, charging party, etc. ========================= TCINVOKE============================= dialogueID: 185413 | operationType: 2 | operation: INAP_ApplyCharging ============================================== ================== [TiINAPApplyCharge] **applyCharge= sendToSCF=1 chargeMode=1 chargeRecordIdentifier=1 chargeAction=2 controllingParty=1 callPartToBeCharged=3

(Charge) (Generate service charge record) (Calling to Called)

calling = "0513123458" called = "1010" translated = "03335174444" specified type = 5 chargeClass=100 surcharge= Type=1 Value=0 chargeRateModulator= Type=1 Value=100 startChargePattern=answerReceived stopChargingPattern=callingPartyOrCalledPartyHooksOn detailedType=1 callSupervision= Method= Type=CostLimit Value=6653 warningBeforeLimit= TimeBeforeLimit=20 inbandInfo= messageID= elementaryMessageID=0x6020025(100794405) (Announcement: You have to hang up in a while)

18- TC_Invoke (SCP to SSP):Connect (CON) (INAP message): The Connect message requests the SSP to connect the users to the designated number. ========================= TCINVOKE============================= dialogueID: 185413 | operation: INAP_Connect ============================================== ================== [TiINAPConnectArg] destinationRoutingAddress="03335174444" callingPartyNumber="0513123458" NatureOfAddressOfCallingNumber=1 (Subscriber Number)

19- TC_Invoke (SSP to SCP):INAP message Event Report BCSM (ERB) is transported. Event Report BCSM (ERB) (INAP Message):

ERB is sent from SSP to SCP when SSP detects the DPs configured by SCP in last RRBE message, reporting the call information to SCP. ========================= TCINVOKE============================= dialogueID: 185413 | operation: INAP_EventReportBCSM ============================================== ================= [TiINAPEventReportBCSMArg] eventTypeBCSM=oAnswer configured) miscCallInfo.messageType=1 (= BCSM Event 7, already (Action-> Notify and Continue)

20- TC_Invoke (SSP to SCP):INAP message Apply Charge Report (ACR) is transported. Apply Charge Report (ACR) (INAP Message): ACR is sent from SSP to SCP, reporting the charge result. The parameters in ACR include: the call start time, call end time, call length, caller number, called number, charging number, fee, etc.

========================= TCINVOKE============================= dialogueID: 185413 | operation: INAP_ApplyChargingReport ============================================== ================== [TiINAPApplyChargeReport] **applyChargeReport= serviceKey=200 chargeMode=1 (Charge) chargeRecordIdentifier=1 chargedPartyIdentityIndicator=127 calling = "0513123458" called = "1010" translateed = "03335174444" specified of compressed = 05 77 77 77 67 ee ee ee ee ee ee Number)

(Card

specified=5077777776EEEEEEEEEEEE startDateAndTime=20060811182139 stopDateAndTime=20060811182148 duration=000 00 09 9 duration=990(10ms) callCost=317 chargeClass=100 reasonForReport=recordCloseFinal timeStamp=20060811182148 supervisionResult= Type=CostLimit Value=317 times=1 baseCallCost=317 end applyChargeReport**

(Start Time) (Stop Time) (Duration of Call) (Charge Class Applied)

(Call Cost)

21- TC_Invoke (SSP to SCP):INAP message Event Report BCSM (ERB) transported. [TiINAPEventReportBCSMArg] eventTypeBCSM=oDisconnect oDisconnectSpecificInfo= releaseCause= "0x10" legID= receivingSideID="\2"

(Event = 9 Encountered) (Normal Call Clearing) (Called Party Hooked on)

22- TC_Invoke (SCP to SSP):INAP message RRBCSME transported. It configures the BCSM Event 10 for abandonment again.

23- TC_Invoke (SSP to SCP):INAP message Event Report BCSM (ERB) transported. It reports the BCSM Event 10, which was configured in case of abandonment and the call flow control given to SCP.

24- TC_Invoke (SCP to SSP):Release Call (RC) (INAP Message) is sent from SCP to SSP, requesting SSP to release the occupied IN call resources. ========================= TC-INVOKE ============================ dialogueID: 185413 | operation: INAP_ReleaseCall ============================================== ================== [TiINAPReleaseCallArg]INAP ReleaseCall: releaseCause= "0x10" (Normal Release Cause)