HP MSR Router Series User Manual

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• Monitor PVC status changes.
• Verify link integrity.
The system supports the following LMI standards:
• ITU-T Q.933 Annex A.
• ANSI T1.617 Annex D.
• Nonstandard LMI (compatible with other vendors).
To communicate properly, the DTE and the DCE must use the same type of LMI.
LMI messages
LMI messages include the following types:
• Status enquiry message—A DTE sends status enquiry messages regularly to a DCE to request the
status of individual PVCs or verify the link integrity.
• Status message—When a DCE receiving a status enquiry message, the DCE responds with a status
message. The status message is used to transmit the PVC status or verify the link integrity.
Status enquiry messages and status messages include the following types:
• Full status—Verifies the link integrity and transmits the PVC status.
• Link integrity verification (LIV)—Verifies the link integrity.
LMI negotiation parameters
Table 7 lists the parameters ITU-T Q.933 Annex A uses for message exchange. You can configure these
parameters to optimize device performance.
Table 7 LMI negotiation parameters
Device
role
Timer/counter
Value
ran
g
e
Default
value
Description
DTE
Full status polling
counter (N391)
1 to 255 6
Sets the ratio of link integrity request messages
sent to full status enquiry messages sent. The
ratio is (N391-1):1.
Error threshold
counter (N392)
1 to 10 3
Sets the number of errors required for LMI to
declare a link dead, within the event count
specified by N393.
Monitored events
counter (N393)
1 to 10 4
Sets the monitored event count. If the number of
errors within the N393 status enquiry messages
reaches N392, a DTE considers that the error
threshold is reached.
Keepalive (link
integrity verification
polling) timer
(T391)
0 to 32767
0 means
LMI
disabled.
10
Sets the interval (in seconds) at which a DTE
sends a status enquiry message. An error is
recorded if the DTE has not received any replies
when the timer expires.
DCE
Error threshold
counter (N392)
1 to 10 3
Sets the number of errors required for LMI to
declare a link dead, within the event count
specified by N393.
Monitored events
count (N393)
1 to 10 4
Sets the monitored event count. If the number of
errors within the N393 status enquiry messages
reaches N392, a DCE considers that the error
threshold is reached.

HP MSR Router Series Specifications

General

Brand	HP
Model	MSR Router Series
Category	Network Router
Language	English