Avocent Access Router Cyclades-PR2000 User Manual

Page 56

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Cyclades-PR2000

Chapter 8 - Data-Link Protocols (Encapsulation)

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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.

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