GFP frame consists of two components:
Core Header: four octets, is mainly used for aligning frame.
Payload Area: including from 4 to 65 535 octets is used to convey higher layer specific protocol information. It consists of two common components: a Payload Header and a Payload Information field. An optional Payload FCS (pFCS 32 bits) field is also supported.
IDLE
frame consists of Core Header only and all bits are “0”.
GFP Working Mode
1）GFP-F（Frame-Mapped GFP）is a PDU-oriented( such as IP/PPP or Ethernet MAC ) adaptation mode.
2）GFP-T（Transparent GFP）is a block-code oriented (such as Fibre Channel or ESCON/SBCON ) adaptation mode.
From group: Transport&Access Network
