In computer networking, the - Transaction Capabilities Application Part (TCAP) is a presentation layer protocol, allows applications (called subsystems) to communicate with each other(over the SS7 network) using agreed-upon data elements. These data elements are called components. Components can be viewed as instructions sent between applications. For example, when a subscriber changes VLR location in a global system for mobile communication (GSM) cellular network, his or her HLR is updated with the new VLR location by means of an UpdateLocation component. TCAP also provides transaction management, allowing multiple messages to be associated with a particular communications exchange, known as a transaction.
TCAP could also mean To Catch a Predator.