Next generation convergence networks require ubiquitous measurement mechanisms able to dynamically assess the performance quality characteristics experienced by the different, aggregated traffic flows traversing end-to-end Internet paths. Existing service measurements fall into two main categories: active and passive. This paper introduces a complementary technique called ‘inline measurements’ that makes use of the extendible features of the emerging IPv6 pro-tocol. Through the exploitation of native IPv6 extension head-ers, measurement triggers and minimal measurement data may be carried in the same packets as the payload data itself, providing a high level of probability that the behaviour of the real user traffic flow is being observed. By adding measure-ment functionality natively, at the network (IPv6) layer, inline measurements can potentially target all transport and applica-tion services, providing an accurate performance evaluation framework for next generation networks. The paper also pre-sents the results from a dynamically configurable prototype implementation in which end-to-end, one-way delay and delay variation of real-time video streams have been measured. Index Terms – active, passive, measurement, monitoring, performance, quality of service, service management, IPv6, extension headers, delay measurement, real-time traffic.