tailieunhanh - Signaling System No.7 Protocol Architecture And Sevices part 38

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 | 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 permission 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 previously established transaction. There are two types of Conversation Messages .