Mobile Application Part (MAP) (GSM MAP)

Transfers between entities of a Public Land Mobile Network (PLMN) information specific to the PLMN in order to deal with the specific behaviour of roaming Mobile Stations (MS)s.

History

XXX - add a brief description of PROTO history

Protocol dependencies

TCAP: Typically, GSM MAP uses TCAP as its transport protocol. The Subsystem number (ssn) is used to identify GSM MAP

Example traffic

No.     Time        Source                Destination           Protocol Info
      1 0.000000    1041                  8744                  GSM MAP  invoke processUnstructuredSS-Request

map-open
    destinationReference: 9656051124006913F6
    1... .... = Extension: No Extension
    .001 .... = Nature of number: International Number (0x01)
    .... 0110 = Number plan: Land Mobile Numbering (ITU-T Rec. E.212) (0x06)
    Address digits: 655011420096316
GSM Mobile Application
    Component: invoke (1)
        invoke
            invokeID: 1
            opCode: localValue (0)
                localValue: processUnstructuredSS-Request (59)
            Data coding: 0x0f
                SMPP Data Coding Scheme: Unknown (0x0f)
                GSM SMS Data Coding
                0000 .... = DCS Coding Group for SMS: SMS DCS: General Data Coding indication - Uncompressed text, no message class (0x00)
                ..0. .... = DCS Text compression: Uncompressed text
                ...0 .... = DCS Class present: No message class
                .... 11.. = DCS Character set: Reserved (0x03)
                GSM CBS Data Coding
                0000 .... = DCS Coding Group for CBS: CBS DCS: Language using the GSM 7-bit default alphabet (0x00)
                ..00 1111 = DCS CBS Message language: Language not specified (0x0f)
            USSD String: *140*0761241377#
            msisdn: 917267415827F2
            1... .... = Extension: No Extension
            .001 .... = Nature of number: International Number (0x01)
            .... 0001 = Number plan: ISDN/Telephony Numbering (Rec ITU-T E.164) (0x01)
            ISDN Address digits: 27761485722

Wireshark

The GSM MAP dissector is fully functional.

Preference Settings

The only preference is "TCAP SSNs" which is a range of SSNs on which gsm_map dissector is triggered.

Example capture file

SampleCaptures/gsm_map_with_ussd_string.pcap

Display Filter

A complete list of GSM MAP display filter fields can be found in the display filter reference

GSMMAP