DTAP (CDMA)
TIA/EIA/IS-634-A, revision A
The Direct Transfer Application Part (DTAP) messages are used to transfer call processing and mobility management messages to and from the MS. The BS does not use DTAP messages, but must map messages going to and coming from the MSC into the appropriate air interface signaling protocol. Transaction IDs are used to associate the DTAP messages with a particular MS and the current call. The format of the header is shown in the following illustration:
Read more about this topic: Cellular Data Communication Protocol