%0 Journal Article %J Computer Communications Journal, Elsevier Science %D 2006 %T IPv6 Deployment: Real Time Applications and QoS Aspects %A Christos Bouras %A Apostolos Gkamas %A Kostas Stamos %A Dimitris Primpas %X This paper gives an overview of the issues related to the QoS mechanisms under IPv6 and the transition of applications to the new Internet protocol. We describe the implementation and testing of a QoS service on IPv6 networks, which is based on the DiffServ architecture (expedited forwarding) and provides strict priorities to packets that are produced from real time applications. The service was implemented and tested at the 6NET large-scale IPv6 network, and additional advanced testing was performed in a local testbed. We present and analyze the results from our tests under a number of different scenarios. In addition, we focus on issues regarding application transition to IPv6 and we briefly discuss as a case study the transition of OpenH323 protocol stack to support IPv6. We also discuss the usage and the expected impact of the new Flow Label field in the IPv6 header. %B Computer Communications Journal, Elsevier Science %P Vol. 29, No. 9, 1393 - 1401 %G eng