A network transport layer accelerator accelerates processing of packets so that packets can be forwarded at wire-speed. To accelerate processing of packets, the accelerator performs pre-processing on a network transport layer header encapsulated in a packet for a connection and performs in-line network transport layer checksum insertion prior to transmitting a packet. A timer unit in the accelerator schedules processing of the received packets. The accelerator also includes a free pool allocator which manages buffers for storing the received packets and a packet order unit which synchronizes processing of received packets for a same connection.