Successful block transfer

In telecommunication, successful block transfer is the transfer of a correct, nonduplicate, user information block[?] between the source user[?] and intended destination user.

Note: Successful block transfer[?] occurs when the last bit of the transferred block crosses the functional interface between the telecommunications system and the intended destination user. Successful block transfer can only occur within a defined maximum block transfer time[?] after initiation of a block transfer attempt. Contrast with successful block delivery[?].