Cyclades Cyclades-PR4000, Installation Manual

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Chapter 10 - Data-Link Protocols (Encapsulation)
Cyclades-PR4000
83
STEP ONE
The first step is to set the general Frame Relay parameters, those applying to all DLCs. This is done in the Frame
Relay Menu. The parameters are shown in the table below. Most of these depend on the standards used by the
Frame Relay Network Provider.
The Local Management Interface (LMI) Protocol provides services not available in simple Frame Relay. It is used
for controlling the connection between the user and the network. It monitors this link, maintains the list of DLCs,
and sends status messages about the PVCs. A separate virtual circuit is created to pass this information (DLCI
0).
Frame Relay Menu CONFIG=>INTERFACE=><LINK>=>ENCAPSULATION =>FRAME RELAY
Parameter Description
SNAP IP Indicates that the Sub-Network Access Protocol should be used. The router on the sending
end must be using the same header type (NLPID or SNAP) as the router on the receiving
end. See the CyROS Reference Guide for more information.
LMI Selects the Local Management Interface specification to be used. ANSI, Group of Four
(defined by the vendors that first implemented Frame Relay), Q933a (defined by ITU-T), and
None (used for a dedicated FR connection without a network).
T391 Interval between the LMI Status Enquiry messages.
N391 Full Status Polling Counter. Full Status Enquiry messages are sent every N391-th LMI Status
Enquiry message.
N392 Error Threshold. The network counts how many events occur within a given period and
considers an interface inactive when the number of events exceeds a threshold.
N393 is the
number of events to be considered and N392 the number of errors within this period. If N392
of the last N393 events are errors, the interface is deemed inactive. A successful event is the
receipt of a valid Status Enquiry message
N393 Monitored Events Count. See the description of N392. This value must be larger than N392.
CIR Committed Information Rate, in percentage of total bandwidth (bandwidth defined in
CONFIG=>INTERFACE=>SWAN =>TRAFFIC CONTROL =>GENERAL =>BANDWIDTH).
Traffic above this rate may be discarded if the network is congested.
Bandwidth
Reservation Enables traffic control per DLCI. Traffic control options appear in the Add DLCI Menu.
FRF-12 When set, indicates the size of the FRF012 fragment in bytes (range: 40-1600).