EXFO FTB/IQS-85100G Packet Blazer for FTB-500/IQS-600 - Manual (Page 392)

Glossary
382 FTB/IQS-85100G
Generic Framing Procedure (GFP)
Other methods have focused on using point-to-point protocol (PPP). The IP
traffic coming to an Ethernet port is encapsulated over a PPP link and
multiple ports can be encapsulated over multilink PPP (ML-PPP) links. By
using an HDLC framing, the PPP traffic is transported over the SONET/SDH
payload. These methods have been standardized within the IETF through
the following Requests for Comments (RFC): RFC 1662, RFC 1990 and RFC
2615. The ITU-T expanded this work by specifying the use of LAPS (very
similar protocol to PPP/HDLC) and specifying IP over LAPS in X.85/Y.1321
and Ethernet over LAPS in X.86/Y1323. All these methods for encapsulating
traffic suffer from the weaknesses of HDLC framing; i.e., limited protection
from frame corruption and the introduction of variable packet sizes
because of its trailer.
GFP has been standardized to better optimize the transport of Ethernet and
other data services over SONET/SDH networks, taking into account both
the pros and cons of ATM and PPP/HDLC and leveraging two new
emerging SONET/SDH capabilities, VCAT and LCAS, that will be discussed
later in this document.