Question 3918 – Computer-Networks

Transport Protocol Class 1 (TP1)​ performs segmentation (fragmentation) and reassembly, plus error recovery. TP1 sequences protocol data units (PDUs) and will retransmit PDUs or re-initiate the connection if an excessive number of PDUs are unacknowledged.
Transport Protocol Class 3 (TP3)​ offers error recovery, segmentation and reassembly, and multiplexing and demultiplexing of data streams over a single virtual circuit. TP3 also sequences PDUs and retransmits them or re-initiates the connection if an excessive number are unacknowledged.