Many services provided over the Internet, like voice over IP and video on demand, increase the demand for assurances concerning the quality of the underlying network. A score of techniques for assurance of quality of service (QoS) have been devised for use within administrative domains. However, when paths cross the border of autonomous systems, assurance of end-to-end QoS remains an unsolved issue. Thereby the key challenge is the establishment of connection-oriented communication flows. We introduce a technique to establish ISO/OSI Layer 3 multi-domain communication paths. The proposed solution does not stress border-routers and is independent of domain-internal policies, while relying on the common forwarding mechanisms.