21.2 Retrieval of routing information

29.1203GPPMobile Application Part (MAP) specification for Gateway Location Register (GLR)Release 17TS

21.2.1 General

The message flows for successful retrieval of routeing information for a mobile terminating call are shown in figure 21.2.1/1 (mobile terminating call which has not been optimally routed) and 21.2.1/2 (mobile-to-mobile call which has been optimally routed).

Notes:

xxx = Optional Procedure

NOTE 1: This service may also be used by an ISDN exchange for obtaining routing information from the HLR.

NOTE 2: TUP or ISUP may be used in signalling between MSCs, depending on the network type between the MSCs. For further details on the TUP and ISUP procedures refer to the following ITU-T Recommendations and ETSI specification:

Q.721‑725 ‑ Telephone User Part (TUP);

ETS 300 356-1 ‑ Integrated Services Digital Network (ISDN); Signalling System No.7; ISDN User Part (ISUP) version 2 for the international interface; Part 1: Basic services.

NOTE 3: As a network operator option, the HLR sends
MAP_PROVIDE_SUBSCRIBER_INFORMATION to the VLR. For further details on the CAMEL procedures refer to GSM 3GPP TS 03.78.

Figure 21.2.1/1: Message flow for retrieval of routeing information (non-optimally routed call)

Figure 21.2.1/2: Message flow for retrieval of routeing information (optimally routed call)

Notes:

xxx = Optional Procedure.

For Optimal Routeing phase 1, only one of the information flows for Provide Subscriber Info and Provide Roaming Number is used. For later phases of Optimal Routeing, the HLR may return a MAP_SEND_ROUTEING_INFORMATION ack after the Provide Subscriber Info information flow, and the GMSC may send a second MAP_SEND_ ROUTEING_INFORMATION, which will trigger the Provide Roaming Number information flow.

TUP or ISUP may be used in signalling between MSCs, depending on the network type between the MSCs. For further details on the TUP and ISUP procedures refer to the following CCITT. Recommendations & ETSI specification:

Q.721‑725 ‑ Telephone User Part (TUP);

ETS 300 356-1 ‑ Integrated Services Digital Network (ISDN); Signalling System No.7; ISDN User Part (ISUP) version 2 for the international interface; Part 1: Basic services.

21.2.2 Process in the GLR to provide a roaming number

The MAP process in the GLR to provide a roaming number for a mobile terminating call is shown in figure 21.2.2/1 (Process PRN_Receive_GLR) and figure 21.2.2/2 (Process PRN_Send_GLR). The MAP process invokes a macro not defined in this subclause; the definition of this macro can be found as follows:

– Receive_Open_Ind see subclause 25.1.

– Receive_Open_Cnf see subclause 25.1.

– Check_Confirmation see subclause 25.2.

Figure 21.2.2/1: Process PRN_Receive_GLR

Figure 21.2.2/2: Process PRN_Send_GLR

21.2.3 Process in the GLR to provide subscriber information

The MAP process in the GLR to provide subscriber information for a mobile terminating call is shown in figure 21.2.3/1 (Process PSI Receive_GLR) and figure 21.2.3/2 (Process PSI Send_GLR). The MAP process invokes a macro not defined in this subclause; the definition of this macro can be found as follows:

Receive_Open_Ind see subclause 25.1.

Receive_Open_Cnf see subclause 25.1.

Check_Confirmation see subclause 25.2.

Figure 21.2.3/1 : Process PSI_Receive GLR

Figure 21.2.3/2 : Process PSI_Send_GLR