ITU-T Y.1331.3 PDF

This Recommendation¹ defines the flexible optical transport network (OTN), known as FlexO, long-reach interfaces that support bonding (i.e. grouping) of multiple of these interfaces such that an OTUCn (n ≥ 1) can be transferred via one or more optical tributary signals (OTSi) over one or more physical interfaces.

The optical parameters associated with FlexO long reach interfaces are provided by application codes, which are specified for 100G in  [ITU-T G.698.2] and are expected to be specified for others rates in a future edition of [ITU-T G.698.2].

A FlexO long reach interface group complements the OTN functionality specified in [ITU-T G.709] and [ITU-T G.709.1] such as B100G OTUCn frame, ODUk/flex, optical interface bonding for short reach interfaces, FlexO interface group management and OTUCn (de)mapping into/from FlexO group payload area, with new functionalities supporting optical interface bonding for long reach interfaces and multiplexing of multiple OYUCn_i into the payload of the FlexO group.

This Recommendation provides specifications for new functionalities that are specific to FlexO long reach interface groups and refers to [ITU-T G.709], [ITU-T G.709.1], [ITU-T G.709.2] and [ITU-T G.798] for already existing functionalities. In addition, some introduction material for the addressed applications is included.

¹ This Recommendation includes an electronic attachment with the worksheets specified in Appendix IV.