Measuring time delay in path MTU discovery in transmitting a packet in IPv4 and IPv6 network

Path MTU Discovery (PMTUD) was initially designed for Internet protocol version 4 (IPv4) to prevent the communication loss due to smaller path MTU. This protocol is then further developed for Internet protocol version 6 (IPv6) with new set of constraints. In IPv4 network, the PMTUD activates when the packets DF bit is set, while as in IPv6, PMTUD is always running for every packet. In this paper, we analyzed the time consumed to transmit a single packet from source to destination in IPv6 and IPv4 network in the presence of PMTUD. Based on our analysis we concluded that the communication time increases with the varying MTU of the intermediate nodes. Moreover, we formulated the mathematical model to determine the communication delay in a network. Our model shows that the asymptotic lower bound for time taken is {\Omega}(n) and the asymptotic upper bound is {\Theta}(n^2), using path MTU discovery.