This Recommendation defines a generic framing procedure (GFP) to delineate octet-aligned, variable-length payloads from higher-level client signals for subsequent mapping into octet-synchronous paths such as those defined in ITU-T Recs G.707/Y.1322, G.8040/Y.1340, and G.709/Y.1331. The Recommendation definitions include the: – frame formats for protocol data units (PDUs) transferred between GFP initiation and termination points; – mapping procedure for the client signals into GFP.