METRODATA LTD
WCM1100 / WCM3100 / WCM-Serial / LHM1000 / LVM2000 User Manual
76-02-082 Rev N
109 of 169
5.3.8.3 Encapsulation
This menu allows the configuration of the packet encapsulation mode for transporting
packets across the WAN port.
Metrodata WCM3100 "" Alarms: Major
ENCAPSULATION, VCG
Encapsulation HDLC
HDLC FCS 16-bit
strip MAC FCS Yes
paYload scrambler Disabled
First CAPITAL - select item
<escape> - exit menu
5.3.8.4 Encapsulation
The WCM product range supports bit synchronous HDLC encapsulation for unframed, or
framed interfaces, or alternatively X.86 LAPS or GFP byte synchronous modes for Framed
interfaces.
5.3.8.4.1 HDLC
HDLC mode is the only option supported on the WCM-Serial, and on WCM1100/3100
when unframed interfaces are selected. HDLC uses flags (0x7E) and bit stuffing to
transmit packets over the WAN interface. When operating in HDLC mode, there are
several parameters which can be changed
5.3.8.4.1.1 HDLC FCS
When a packet is encapsulated a frame check sequence is added to the end of the packet
to enable transmission error detection. The options here are
16 bit
A 16 bit FCS is calculated and added to the packet
32 bit
A 32 bit FCS is calculated and added to the packet
Both ends of the link MUST match otherwise traffic will not flow, For operation with an
unmanaged WC product, 16 bit mode must be used.