Signaling System No.7 Protocol Architecture And Sevices part 38 pdf

ANSI Protocol Message Contents The following sections describe the set of ANSI messages, the fields included in each, and specify the mandatory and optional fields for each message type. The message types specified by ANSI include: • Unidirectional • Query • Conversation • Response • Protocol abort • User abort • Dialogue portion In the messages, fields marked as "Mandatory*" must be present, but their contents can be empty. Unidirectional Message The Unidirectional Message is sent when no reply is expected. Table 10-14 lists the message contents. Table 10-14. Unidirectional Message Fields Unidirectional Message Fields Mandatory/Optional Package Type Identifier Total Message Length Mandatory Transaction ID Identifier Transaction ID Length (Set to 0) Mandatory Dialogue Portion Optional Component Sequence Identifier Component Sequence Length Components Mandatory Query With/Without Permission The Query Message is used to initiate a transaction. There are two types of Query messages: Query with Permission and Query without Permission. The Query with Permission message gives the receiving node permission to end the transaction at any time. The Query without Permission message does not give the receiving node p ermission to end the transaction. After receiving this message, the transaction remains established until the originator ends it or sends a subsequent message giving the receiving node permission to end the transaction. Table 10-15 lists the message contents. Table 10-15. Query Message Fields Query With/Without Permission Message Fields Mandatory/Optional Package Type Identifier Total Message Length Mandatory Transaction ID Identifier Transaction ID Length Originating Transaction ID Mandatory Dialogue Portion Optional Component Sequence Identifier Component Sequence Length Components Optional Conversation With/Without Permission The Conversation Message is used to exchange additional information for a p reviously established transaction. There are two types of Conversation Messages: Conversation with Permission and Conversation without Permission Message. The Conversation with Permission Message gives the receiving node permission to end the transaction at any time. The Conversation without Permission message does not give the receiving node p ermission to end the transaction. Af t er receiving this message, the transaction remains established until the originator ends it or sends a subsequent message giving the receiving node permission to end the transaction. Table 10-16 lists the message contents. Table 10-16. Conversation Message Fields Conversation With/Without Permission Message Fields Mandatory/Optional Package Type Identifier Total Message Length Mandatory Transaction ID Identifier Transaction ID Length Originating Transaction ID Responding Transaction ID Mandatory Dialogue Portion Optional Component Sequence Identifier Component Sequence Length Components Optional R esponse Messa g e The Response Message is sent to end a transaction. Table 10-17 lists the message contents. Table 10-17. Response Message Fields Response Message Fields Mandatory/Optional Package Type Identifier Total Message Length Mandatory Transaction ID Identifier Transaction ID Length Responding Transaction ID Mandatory Dialogue Portion Optional Component Sequence Identifier Component Sequence Length Components Optional P rotocol Abort (P-Abort) Message The Protocol Abort (P-Abort) Message is sent to terminate a previously established transaction. A P-Abort is initiated because of an error at the TCAP protocol layer. Table 10-18 lists the message contents. Table 10-18. Abort Message Fields Abort (P-Abort) Message Fields Mandatory/Optional Message Type Total Message Length Mandatory Transaction ID Identifier Transaction ID Length Transaction ID Mandatory P-Abort Cause Identifier Mandatory P-Abort Cause Length P-Abort Cause User Abort (U-Abort) Message The User Abort (U-Abort) Message is sent to terminate a previously established transaction. A U-Abort is initiated at the Application Layer based on application logic. Table 10-19 lists the message contents. Table 10-19. User Abort Message Fields Abort (U-Abort) Message Fields Mandatory/Optional Message Type Total Message Length Mandatory Transaction ID Identifier Transaction ID Length Transaction ID Mandator Dialogue Portion Optional U-Abort Information Identifier U-Abort Information Length U-Abort Information Mandatory  . ANSI Protocol Message Contents The following sections describe the set of ANSI messages, the fields included in each, and specify the mandatory and optional fields for each. transaction. Table 10- 17 lists the message contents. Table 10- 17. Response Message Fields Response Message Fields Mandatory/Optional Package Type Identifier Total Message Length Mandatory Transaction. Permission and Query without Permission. The Query with Permission message gives the receiving node permission to end the transaction at any time. The Query without Permission message does not give