An IPv6 network congestion measurement based on network time protocol

Abstract

For the past decade, Internet Protocol version 6 (IPv6) has slowly been implemented alongside Internet Protocol version 4 (IPv4) on existing network infrastructure. This overlaying implementation, IPv6 on network infrastructure designed for IPv4, not only makes the internet routing very dynamic but also contributes to network congestion. The fundamental metric of network congestion measurement, i.e., Internet Control Message Protocol (ICMP) version 6, does not accurately capture the congestion occurred only in the network portion since it employs Round-Trip Time (RTT), which includes packet processing time, as a key indicator. Through an experiment, we demonstrate the shortcoming of ICMP in revealing the actual network congestion and propose the use of Network Time Protocol (NTP) version 4 as a metric of network congestion measurement. We deployed three NTP servers and clients in London, Singapore, and Thailand while monitoring network congestion from an NTP client deployed in Los Angeles. We observe that the NTP offset can accurately indicate the network congestion, measured from the monitoring station to the NTP server.