Analysis on packet resequencing for reliable network protocols

Packets are sometimes disordered in the network. Reliable protocols such as TCP require packets to be accepted, i.e., delivered to the receiving application, in the order they are transmitted at the sender. In order to do so, the receiver’s transport layer must resequence the packets with the help of a resequencing buffer. Even if the application can consume the packets infinitely fast, the packets may still be delayed for resequencing. In this paper, we model packet disordering by adding an independently and identically distributed (IID) random propagation delay to each packet and analyze the required buffer size for packet resequencing and the resequencing delay for an average packet. We demonstrate that these two quantities can be significant and show how they scale with the network bandwidth.