Alcatel-Lucent 1643 AMS User's Operation Manual page 380

Traffic provisioning
IDLE
GFP, standardized by the ITU-T in the recommendations G.7041 and Y.1303, is a very
efficient encapsulation protocol because it has a fixed and small overhead per packet.
In earlier versions (prior to the Garnet network release of June 2002) of the
TransLAN
method is used for VC-12 and/or VC-3 based designs (10/100BASE-T Ethernet / Fast
Ethernet cards). EoS is a proprietary encapsulation protocol, based on the ANSI
T1X1.5/99-268r1 standard, and can be regarded as a precursor of GFP. EoS and GFP
are both length-based encapsulation methods. EoS is similar to GFP in terms of frame
delineation and mapping (incl. scrambling); differences between the two encapsulation
methods lie in the size and interpretation of the EoS/GFP encapsulation core headers,
as well as the length of the Idle frames.
The generic framing procedure, framed mode (GFP-F) compliant to the ITU-T Rec.
G.7041 is available on all TransLAN
Mercury network release of January 2003.
The following GFP encapsulation are possible:
• Mapping of Ethernet MAC frames into Lower Order SDH VC12–Xv
• Mapping of Ethernet MAC frames into Lower Order SDH VC3–Xv
• Mapping of Ethernet MAC frames into Higher Order SDH VC4–Xv.
Virtual concatenation
The virtual concatenation function arranges the Ethernet frames into the right SDH
virtual container. It is possible to map the client's data signal over a number of
grouped virtual containers.
Related information
Please refer to
VC12–Xv virtual concatenation
The 1643 AM supports virtual concatenation of Lower Order SDH VC-12 as inverse
multiplexing technique to size the bandwidth of a single internal WAN port for
transport of encapsulated Ethernet and Fast Ethernet packets over the SDH/SONET
network. This is noted VC12-Xv, where X = 1...5. Usage is in conformance with
ITU-T G.707 Clause 11 (2000 Edition) and G.783 Clause 12.5 (2000).
....................................................................................................................................................................................................................................
8-28
GFP
Ethernet frame
HEADER
GFP
Ethernet frame
HEADER
®
equipment, the Ethernet over SDH (EoS) encapsulation and mapping
"Virtual concatenation" (p. 8-40)
Alcatel-Lucent - Proprietary
See notice on first page
IDLE IDLE
HEADER
Ethernet frame IDLE IDLE
®
products since the Garnet Maintenance /
for more detailed information.
Ethernet over SDH
GFP
365-312-807R7.2
Issue 4, May 2007