This Recommendation defines a generic framing procedure (GFP) to encapsulate variable-length payload of various client signals for subsequent transport over SDH@ PDH and OTN networks as defined in [ITU-T G.707]@ [ITU-T G.8040] and [ITU-T G.709]. This Recommendation defines the: ?C frame formats for protocol data units (PDUs) transferred between GFP initiation and termination points; ?C mapping procedure for the client signals into GFP. The framing procedure described in this Recommendation can be applied to both the encapsulation of entire client frames (frame-mapped GFP) in which a single client frame is mapped into a single GFP frame@ and to character-mapped transport (transparent GFP) in which a number of client data characters are mapped into efficient block codes for transport within a GFP frame.