  Isolation is one of the more relevant attributes associated to the idea of
network slicing, introduced by 5G services. Through isolation it is expected
that slices from different customers could gracefully coexist without
interfering each other, in the sense that whatever misbehavior or unforeseen
demand from one slice customer could not affect the communication service
received by any other slice customer supported atop the same physical transport
infrastructure. This paper surveys and compare different technical approaches
that can be taken for providing distinct isolation levels in the transport
network, as a major component of end-to-end network slices. Furthermore, a
number of isolation feasibility indicators are defined and proposed. These
indicators are based on the approaches referred before, as a mean of guiding
orchestration decisions at the time of provisioning or reconfiguring the
transport slices in the network.
