EXFO Power Blazer 88200NGE, User Manual, Page: 830 / 887

Glossary
820
88000 Series
Generic Framing Procedure (GFP)

Type HEC (tHEC) Field : A two-octet field that contains a CRC-16
sequence to protect the integrity of the type field. The tHEC
sequence is computed over the core header bytes using standard
CRC-16. As with the cHEC, CRC-16 enables both single-bit error
correction and multibit error detection.

Channel Identifier (CID)
: A one-byte field that is only available
when the EXI field is configured to Linear. The CID byte is used to
indicate one of 256 communication channels at a GFP termination
point.

Spare
: A one-byte field that is only available when the EXI field is
configured to Linear. This field is reserved for future use.

Extension HEC (eHEC)
: A two-byte field that contains a CRC-16
check sequence that protects the integrity of the contents of the
extension. CRC-16 enables both single-bit correction and multibit
error detection.
The figure below explains how (in GFP-F) the transmitter encapsulates
one entire frame of the client data.
GFP-F vs. GFP-T Frame Structure