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Chapter 2 Command Descriptions 35
lcp echo requests
The number of Link Control Protocol (LCP) echo requests that have been
sent after a “quiet” interval, in order to test the PPP link and/or keep it
alive. For Digi Cellular products, LCP echo requests are typically not
used.
SureLink Statistics
Digi SureLink™ provides an “always-on” mobile network connection to
ensure that a Digi Cellular Family device is in a state where it can connect
to the network.
The statistics displayed for Digi SureLink pertain to the periodic tests,
known as Link Integrity Monitoring tests, that are run over the established
PPP connection to ensure that end-to-end communication is possible.
There are three Link Integrity Monitoring tests available: There are three
tests available: Ping Test, TCP Connection Test, and DNS Lookup Test.
For descriptions of these tests, see "set surelink" on page 202.
In these SureLink statistics, a “session” is a PPP session. The session
statistics are reset to zero at the start of a new PPP connection. The “total”
statistics are the accumulated totals for all sessions since the device
booted. The “tests” are the SureLink Link Integrity Monitoring tests that
have been configured to be run when the mobile network connection is
established.
session successes
The number of times a configured test was attempted and succeeded in
a PPP session.
session failures
The number of times a configured test was attempted but failed in a PPP
session.
session consecutive failures
The number of consecutive failures for a test, with no success. When a
test is successful, the consecutive failures counter is reset to zero. The
consecutive failures counter indicates a device's “progress” toward the
configured maximum number of consecutive failures, after which the
PPP link is taken down (and restarted).
session bypasses
If a configuration parameter is bad, a test is bypassed rather than
considered to have succeeded or failed. This means the test was not run.
If the PPP connection goes down while a test is in progress, that test may
be classified as bypassed, since it could not be run. (Note that the PPP
link may come down for many reasons, independent of SureLink testing.)
total successes
The total number of times a configured test was attempted and
succeeded since the Digi device was booted.
total failures
The total number of times a configured test was attempted but failed
since the Digi device was booted.