A method and system for partial reassembly of data frames reconstructed from data cells received from a network data stream includes partially reassembling the header cells and the last cell of each frame and passing the remainder of data frame cells to a capture buffer in an unassembled state. Since the partially reassembled data frames include only a subset of each frame, they can be processed at the full line-rate of the network data stream without causing an overflow. The cells in the partially reassembled frames are only those cells required for functions that must be performed at the full line rate.