Appendix D. TCAP Messages and Components

The tables in this appendix summarize Transaction Capabilities Application Part (TCAP) messages and components, and explain the purpose of each. For an introduction to TCAP, refer to Chapter 10, "Transaction Capabilities Application Part (TCAP)."

Table D-1 shows the TCAP messages used in ITU-T networks.

Table D-1. ITU TCAP Message Reference

Binary Code	Message Name	Purpose
0 1 1 0 0 0 0 1	Unidirectional	Used to send components to another TCAP user without establishing a transaction. No Transaction ID is allocated. No response is expected when this message is received.
0 1 1 0 0 0 1 0	Begin	Initiates a transaction. The transaction ID is allocated and included in all messages that are associated with the transaction. A TCAP user can respond with an End or Continue message.
0 1 1 0 0 1 0 0	End	Ends an existing transaction. The Transaction ID is released when this message is received.
0 1 1 0 0 1 0 1	Continue	Sent when a transaction has been established and further information exchange is needed. A Transaction ID is allocated and used in all messages associated with the transaction. The Continue message includes both an Origination Transaction ID and a Destination Transaction ID. A TCAP user can respond with an End or Continue message.
0 1 1 0 0 1 1 1	Abort	Indicates that an abnormal condition has occurred. The transaction is ended and all associated Transaction IDs are released. The abort might be initiated by the TCAP user (U-Abort) or the protocol itself (P-Abort).

Table D-2 shows the TCAP messages used in ANSI networks.

Table D-2. TCAP Message Reference (ANSI)

Binary Code	Message Name	Purpose
1 1 1 0 0 0 0 1	Unidirectional	Used to send components to another TCAP user without establishing a transaction. No Transaction ID is allocated. No response is expected when this message is received.
1 1 1 0 0 0 1 0	Query With Permission	Initiates a transaction and allows the receiving TCAP user to end the transaction. A Transaction ID is allocated and included in all messages associated with the transaction. The normal response from a TCAP user is a Conversation or Response message.
1 1 1 0 0 0 1 1	Query Without Permission	Initiates a transaction but does not allow the receiving TCAP user to end the transaction. A Transaction ID is allocated and included in all messages associated with the transaction. The normal response from a TCAP user is a Conversation message.
1 1 1 0 0 1 0 0	Response	Ends an existing transaction. The Transaction ID is released when this message is received.
1 1 1 0 0 1 0 1	Conversation With Permission	Sent when a transaction has been established and further information exchange is needed. The receiving TCAP user is allowed to end the transaction. A Transaction ID is allocated when the first Conversation message is sent and is used in subsequent messages associated with the transaction. The Conversation With Permission message includes both an Origination Transaction ID and a Destination Transaction ID. The normal response from a TCAP user is a Conversation or Response message.
1 1 1 0 0 1 1 0	Conversation Without Permission	Sent when a transaction has been established and further exchange of information is needed. The receiving TCAP user is not allowed to end the transaction. A Transaction ID is allocated when the first Conversation message is sent and is used in subsequent messages associated with the transaction. The Conversation With Permission message includes both an Origination Transaction ID and a Destination Transaction ID. The normal response from a TCAP user is a Conversation message.
1 1 1 1 0 1 1 0	Abort	Indicates that an abnormal condition has occurred. The transaction is ended and all associated Transaction IDs are released. The abort might be initiated by the TCAP user (U-Abort) or the protocol itself (P-Abort).

Table D-3 shows the TCAP components used in ITU and ANSI networks.

Table D-3. TCAP Component Type Reference (ITU/ANSI)

ITU Binary Code	ANSI Binary Code	Component Type	Purpose
1 0 1 0 0 0 0 1	1 1 1 0 1 0 0 1	Invoke	Invokes an operation at a remote node. This is a request to have an action, such as translating a number or creating a connection performed.
1 0 1 0 0 0 1 0	1 1 1 0 1 01 0	Return Result (Last)	Returns the result of a successfully invoked operation. No subsequent components are to be sent.
1 0 1 0 0 0 1 1	1 1 1 0 1 0 1 1	Return Error	Indicates that an error has occurred at the application or user level.
1 0 1 0 0 1 0 0	1 1 1 0 1 1 0 0	Reject	Indicates that an error has occurred at the protocol level.
	1 1 1 0 1 1 0 1	Invoke (Not Last)	Invokes an operation at a remote node. Further responding components are expected. Applies only to ANSI Networks.
1 0 1 0 0 1 1 1	1 1 1 0 1 1 1 0	Return Result (Not Last)	Returns the result of a successfully invoked operation. Subsequent components are sent.