In this section:
The user interface to the SCCP within the DSC Platform is message-based. These messages are conveyed over a TCP/IP socket and use network byte ordering, where the Most Significant Bit (MSB) is sent first and the Least Significant Bit (LSB) is sent last.
When initiating a connection between SCCP and its IP user application, the first message exchanged prior to the registration is the version message that lets SCCP and this user application know what UAP SCCP version is supported. The version message was introduced in UAP SCCP version 2. SCCP assumes UAP SCCP version 1 if no version message is received.
The format for all SCCP messages is shown in the following table.
SCCP Message Format
| Field Name | Offset | Description |
|---|---|---|
| Message Header | 0 1 2 3 | The message header (see Using a Message Header to Delimit Message Boundaries for more information). |
| Message Type | 4 5 | The SCCP message type (primitive and management). |
| Parameter ID (1) | 6 7 | The identifier of the parameter that follows. Encoded as MSB first, LSB last. |
| Parameter Length (1) | 8 9 | The length of the parameter that follows. Encoded as MSB first, LSB last. |
| Parameter Value (1) | 10 : n | The parameter value. The offset n is equal to 10+(parameterLength-1). |
| Parameter ID (2) | n+1 n+2 | The identifier of the parameter that follows, if required. |
| Parameter Length (2) | n+3 n+4 | The length of the parameter that follows, if required. |
| Parameter Value (2) | n+5 : m | The parameter value, if required. |
More parameters, if required. | ||
Message Type
The following table lists the SCCP user interface message types, their associated values, category, and version. Message types are direction-based. For information about each message type, see Connectionless Services and Primitives, Connection-Oriented Primitives, and SCCP Management Services and Primitives.
Message Types
| Message Type | Value | Category | Version |
|---|---|---|---|
| N-UNIDATA-REQ | 0 | Connectionless | 1 |
| N-UNIDATA-IND | 1 | Connectionless | 1 |
| N-NOTICE-IND | 2 | Connectionless | 1 |
| N-COORD-REQ (not supported) | 3 | N/A | 1 |
| N-COORD-RSP (not supported) | 4 | N/A | 1 |
| N-COORD-IND | 5 | User Management | 1 |
| N-COORD-CNF | 6 | User Management | 1 |
| N-STATE-REQ | 7 | User Management | 1 |
| N-STATE-IND | 8 | User Management | 1 |
| N-PCSTATE-IND | 9 | User Management | 1 |
| N-REGISTER-SSN-REQ | 10 | User Management | 1 |
| N-REGISTER-SSN-RSP | 11 | User Management | 1 |
| N-DEREGISTER-SSN-REQ | 12 | User Management | 1 |
| N-DEREGISTER-SSN-RSP | 13 | User Management | 1 |
| Reserved | 14-19 | N/A | N/A |
| N-CONNECT-REQ | 20 | Connection-Oriented | 1 |
| N-CONNECT-IND | 21 | Connection-Oriented | 1 |
| N-CONNECT-RSP | 22 | Connection-Oriented | 1 |
| N-CONNECT-CNF | 23 | Connection-Oriented | 1 |
| N-DATA-REQ | 24 | Connection-Oriented | 1 |
| N-DATA-IND | 25 | Connection-Oriented | 1 |
| N-DISCONNECT-REQ | 26 | Connection-Oriented | 1 |
| N-DISCONNECT-IND | 27 | Connection-Oriented | 1 |
| N-REGISTER-APPID-REQ | 28 | User Management | 4 |
| N-REGISTER-APPID-RSP | 29 | User Management | 4 |
| N-DEREGISTER-APPID-REQ | 30 | User Management | 4 |
| N-DEREGISTER-APPID-RSP | 31 | User Management | 4 |
| N-VERSION | 32 | User Management | 2 |
| N-MTP3-NA-CONFIGURATION | 33 | User Management | 5 |
| N-CONNECTION-SETUP | 34 | User Management | 6 |
| N-NOTICE-REQ | 143 | Connectionless | 1 |
| N-DESTINATION-AUDIT-REQ | 150 | User Management | 1 |
Parameter ID
The parameter identifier (ID) indicates the type and value that follows. Parameter identifiers and their associated values are listed in the following sections.
Note
Parameters are mandatory (M) or optional (O) based on message type and direction.
Overview
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