Scheme to measure One-Way Delay Variation with detection and removal of clock skew

One-Way Delay Variation (OWDV) has become increasingly of interest to evaluate network state and service quality, especially for real-time and streaming services such as VoIP and video. Measurement of these parameters needs to be performed with the layout infrastructure. Many schemes for OWD measurements require clock synchronization at the source and destination through Global-Positioning System (GPS) or the Network Time Protocol (NTP). In clock-synchronized approaches, the accuracy of the measurement of OWDV depends on the achieved accuracy of clock synchronization. GPS provides high-accuracy clock synchronization. However, the deployment of GPS on legacy network equipment might be slow and costly. This paper proposes a method for measuring OWDV without recurring to clock synchronization. However, clock skew may affect the measurement of OWDV. The proposed approach is based on the measurement of Inter-Packet Delay (IPD) and Accumulated OWDV (AOWDV). This paper shows the performance of the proposed scheme via simulation and through experimentation in a VoIP network. The presented simulation and experimental results indicate that clock skew can be efficiently measured and removed and that OWDV can be measured without requiring clock synchronization.