This document specifies a framework and mapping from slices in 5G
mobile systems to transport slices in IP and Layer 2 transport
networks. Slices in 5G systems are characterized by latency bounds,
reservation guarantees, jitter, data rates, availability, mobility
speed, usage density, criticality and priority should be mapped to
transport slice characteristics that include bandwidth, latency and
criteria such as isolation, directionality and disjoint routes. Mobile
slice criteria need to be mapped to the appropriate transport slice
and capabilities offered in backhaul, midhaul and fronthaul
connectivity segments between radio side network functions and user
plane function (gateway). This document describes how mobile network
functions map its slice criteria to identifiers in IP packets that
transport segments use to grant transport layer services. This is
based on mapping between mobile and IP transport underlays (IPv6,
MPLS, IPv4, Segment Routing). Applicability of this framework and a
new transport network underlay routing mechanism, Preferred Path
Routing (PPR), which brings slice properties and works with any
underlying transport (L2, IPv4, SR and MPLS) is also discussed.