Message Types The TCAP message type (which is referred to as package type in ANSI) identifies the type of message being sent within the context of a transaction. Table 10-1 lists the seven package types for ANSI and Table 10-2 lists the five message types for ITU. | Message Types The TCAP message type which is referred to as package type in ANSI identifies the type of message being sent within the context of a transaction. Table 10-1 lists the seven package types for ANSI and Table 10-2 lists the five message types for ITU. Table 10-1. Package Types for ANSI ANSI Package Types Hex Value Description Unidirectional 11100001 Sent in one direction and expects no reply. Query with Permission 11100010 Initiates a transaction giving the receiving node permission to end the transaction. Query without Permission 11100011 Initiates a transaction but does not allow the receiving node to end the transaction Response 11100100 Ends a transaction. Conversation with Permission 11100101 Continues a transaction giving the receiving node permission to end the transaction. Conversation without Permission 11100110 Continues a transaction but does not allow the receiving node to end the transaction. Abort 11110110 Sent to notify the destination node that an established transaction has been terminated without sending any further components that might be expected. Table 10-2. Message Types for ITU ITU Message Types Hex Value Description Unidirectional 01100001 Sent in one direction and expects no reply. Begin 01100010 Initiates a transaction. Reserved 01100011 Not used. End 01100100 Ends a transaction. Continue 01100101 Continues an established transaction. Reserved 01100110 Not used. Abort 01100111 Sent to notify the destination node that an established transaction has been terminated without sending any further components that might be expected. The message type also infers the stage of transaction processing. Figure 10-4 shows an example of an ITU conversation and an equivalent ANSI conversation. In ITU a Begin message always starts a transaction and an End message normally ends the transaction. The Transactions section of this chapter discusses an exception to this rule. The equivalent ANSI messages that begin and end transactions are Query with
