Page 1324 - 5G Basics - Core Network Aspects

2 Transport aspects

The R-T topology is used in Figure 6-1, to draw an analogy between FlexO and FlexE use cases presented in
[OIF FlexE IA]. The ODUk/flex (which can be a rate higher than 100Gbit/s) is the transport service (path) and
maintenance entity in the OTN transport/switch network. The ODUCn/OTUCn is the section and FlexO
provides the interfacing capabilities (e.g., FEC, bonding and scrambling).

Figure 6-2 – Example FlexO inter-domain handoff

The example of Figure 6-2 shows a FlexO inter-domain interface used as a handoff between two OTN
switch/transport administrative domains (A and B). The administrative domains can represent different
carriers, different equipment vendors within a carrier or different segments (metro vs core) within a carrier.
The OTUCn is the regen section (RS), the ODUCn is the multiplexed section (MS) and the m*OTUC is the
FlexO group bonded using m*100G FlexO interfaces.

7 Structure and processes
This clause introduces the functions associated with a FlexO group and the basic signal structure, processes
and atomic functions.

7.1 Basic signal structure
The FlexO group interface in this recommendation is only specified for short-reach applications. The FlexO
group functional model is specified in [ITU-T G.872]. The physical optical interface specifications are beyond
the scope of this recommendation.
The information structure for FlexO groups is represented by information containment relationships and
flows. The principal information containment relationship is described in Figure 7-1.

1314