A dynamic virtual path slice is an IP packet flow with end to end resource guarantees. A virtual path slice leverages the existing packet forwarding infrastructure to offer end to end resource guarantees across single or multiple autonomous systems. A virtual path slice benefits from working in a mixed IP and MPLS environment.

A Virtual Path Slice combines loose and hard forwarding models to deliver end to end QoS support across heterogeneous networks. The combined loose and hard model concept was developed by the EuQoS consortium.

The EuQoS consortium comprised over twenty organisations under the leadership of Telefonica with a research agenda to identify solutions for End-to-End Quality of Service Over Heterogeneous Networks. (See reference End-to-End Quality of Service Over Heterogeneous Networks, Braun, T., Diaz, M., Gabeiras, J.E., Staub, Th, Springer, ISBN: 978-3-540-79119-5).