Abstract
Skype nodes generate a substantial part of real-time bi-directional video traffic nowadays. Employing a range of adaptive mechanisms, the application configures video streaming to meet the requirements of the communication and constraints of the underlying network. While other related works focus on passive network monitoring of Skype data flows, this paper studies Skype as a point-to-point streaming engine of video, beyond standard video calling. The emphasis is on the objective video quality as perceived by viewers. We built a testbed to generate network perturbations and stream certain videos between Skype nodes. We examine how network impairments affect objective metrics (i.e. PSNR and SSIM index) of the video and Skype's ability to reconstruct the original sample. The results suggest that Skype is weak at delivering good quality for high motion videos and that it is slow at recovering after a long period of high packet loss. © 2011 ACM.