scope:

This delimiting module defines a mechanism for encoding SDUs within PDUs. It is unnecessary to use this module if each PDU carries precisely one SDU. The delimiting module produces on input, one or more User-Data fields for EFCP to create PDUs; and on output, depending on QoS parameters, complete, incomplete, or partial SDUs for the user of the flow. (Partial delivery refers to whole SDUs that are delivered incrementally, while incomplete delivery refers to an SDU that may have pieces missing. This implies that partial delivery of incomplete SDUs is possible.) The described mechanism covers a range of policy options, allowing fragmentation of SDUs, concatenation of SDUs, and both fragmentation and concatenation of SDUs simultaneously. It also provides additional information needed for delivery despite gaps in the SDU stream, if delivery across a gap is permitted by the QoS-cube for the flow. The delimiting policy may be different between QoS-cubes. This module could be used with several QoScubes with different constraints on what flags might appear.