HP MSR Router Series Wan Access Configuration Manual page 242

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
DTE
DCE
Value
Timer/counter
range
Full status polling
1 to 255
counter (N391)
Error threshold
1 to 10
counter (N392)
Monitored events
1 to 10
counter (N393)
0 to 32767
Keepalive (link
integrity verification
0 means
polling) timer
LMI
(T391)
disabled.
Error threshold
1 to 10
counter (N392)
Monitored events
1 to 10
count (N393)
Default
Description
value
Sets the ratio of link integrity request messages
6 sent to full status enquiry messages sent. The
ratio is (N391-1):1.
Sets the number of errors required for LMI to
3 declare a link dead, within the event count
specified by N393.
Sets the monitored event count. If the number of
errors within the N393 status enquiry messages
4
reaches N392, a DTE considers that the error
threshold is reached.
Sets the interval (in seconds) at which a DTE
sends a status enquiry message. An error is
10
recorded if the DTE has not received any replies
when the timer expires.
Sets the number of errors required for LMI to
3 declare a link dead, within the event count
specified by N393.
Sets the monitored event count. If the number of
errors within the N393 status enquiry messages
4
reaches N392, a DCE considers that the error
threshold is reached.
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