METRODATA LTD
WCM1100 / WCM3100 / WCM-Serial / LHM1000 / LVM2000 User Manual
76-02-082 Rev N
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5.3.8.4.3 GFP
The WCM1100 offers GFP encapsulation when used on a framed, byte synchronous
interface. GFP uses idle packets to delimit and pad, and appends a four byte header to
the packet along with a 32 bit FCS. Additional options are:
Metrodata WCM1100 "" Alarms: Major
ENCAPSULATION, VCG
Encapsulation GFP
GFP FCS Enabled
strip MAC FCS Yes
paYload scrambler Enabled
First CAPITAL - select item
<escape> - exit menu
5.3.8.4.3.1 GFP FCS
The GFP FCS, frame check sequence, may be added to the frame to provide error
protection. The GFP FCS should always be enabled as this will allow the decapsulator to
detect frame errors.
5.3.8.4.3.2 Strip MAC FCS
A LAN packet is protected by a 32 bit FCS. Since the encapsulator will add an GFP FCS it
is possible to save bandwidth by removing the Ethernet FCS and recalculate at the far
end.
Both ends of the link MUST match otherwise traffic will not flow.
5.3.8.4.3.3 Payload Scrambler
For security purposes and to ensure a good ones density an X^43 scrambler may be
applied
Both ends of the link MUST match otherwise traffic will not flow.
