User manual

set surelink
204 Chapter 2 Command Descriptions
test={ping|tcp|dns}
The Link Integrity Monitoring test to be run.
Each test can be used to demonstrate that two-way communication is
working over the mobile connection. This variety of tests is provided
because different mobile networks or firewalls may allow or block Internet
packets for various services. The appropriate test may be selected
according to mobile network constraints and user preference.
The link integrity tests are performed only while the mobile connection is
established. If the mobile connection is disconnected, the link integrity
tests are suspended until the connection is established again.
For the link integrity tests to provide meaningful results, the remote or
target hosts must be accessible over the mobile connection and not
through the LAN interface of the device (if it has one). That is, the settings
should be configured to guarantee that the mobile connection is actually
being tested.
The link integrity test settings may be modified at any time. The changes
are used at the start of the next test interval.
ping
Ping test. This test uses “ping” (ICMP) as a test to verify the integrity
of the mobile connection. The test is successful if a valid ping reply is
received in response to the ping request sent. The ping test actually
sends up to three ping requests, at three second intervals, to test the
link. When a valid reply is received, the test completes successfully
and immediately. If a reply is received for the first request sent, there
is no need to send the other two requests.
Two destination hosts may be configured for this test. If the first host
fails to reply to all three ping requests, the same test is attempted to
the second host. If neither host replies to any of the ping requests sent,
the test fails. The primary and secondary addresses may be either IP
addresses or fully qualified domain names.
tcp
TCP Connection Test. This test creates a new TCP connection as a
test to verify the integrity of the mobile connection. The test is
successful if a TCP connection is established to a specified remote
host and port number. If the remote host actively refuses the
connection request, the test is also considered to be successful, since
that demonstrates successful two-way communication over the mobile
connection. The TCP connection test waits up to 30 seconds for the
connection to be established or refused. When the TCP connection is
established, the test completes successfully, and the TCP connection
is closed immediately.
Two destination hosts may be configured for this test. If the first host
fails to establish (or refuse) the TCP connection, the same test is
attempted to the second host. If neither host successfully establishes
(or refuses) the TCP connection, the test fails. The primary and
secondary addresses may be either IP addresses or fully qualified
domain names.