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Service Level Verification

When licensed for each Local Manager, the Service Level Verification (SLV) module ensures consistent, high levels of IT service by synthetically measuring the performance of critical network services and applications from the end-user's perspective and comparing the results to drive automation decisions.

You can use SLV to execute Voice over IP (VoIP) calls, web transactions, and TCP SYN/ACK handshakes to verify end-to-end network functionality.

This topic focuses on the activation, configuration, and usage of SLV in a Local Manager CLI environment.

SLV Tests

There are three types of SLV tests available:

Web-based Transactions

This test performs an HTTP request from the Local Manager to a remote destination. DNS lookup, connection setup time, time to first byte, and time to last byte are measured. Also collected are the HTTP result code and the first 1,024 bytes of HTML for further validation testing.


Often called a TCP handshake, the round-trip connection establishment process more accurately measures the network portion of communication by isolating much of the delay associated with the network itself, leaving out the overhead of the application layer. This test has the smallest network impact.

VoIP / IP Telephony (IPT)

For IPT environments, the Local Manager captures 47 specific RTP Control Protocol (TRCP) metrics that characterize the network's ability to transport VoIP traffic. Pre-encoded voice calls with phonetically balanced Harvard sentences are used to gauge VoIP performance. Metrics such as jitter, latency, packet loss, MOS scores, and R values can be evaluated by the Local Manager's rules engine.

Installing an SLV License

Service Level Verification is an optional, add-on feature available for purchase from Lantronix. Contact your account executive or for more information.

Once you have purchased a license, you will need to install it on the Control Center.

Creating SLV Tests

CC: Inventory > Local Manager Summary > Automation > SLV Tests

Use the config slv command with either http, tcp, or ipt as a secondary argument to create SLV tests. Use the ? subcommand to view available editor options.


config slv <type> <testname>


SLV test names can only contain alphanumeric characters.


Use the config slv http {testname} command to create an HTTP test.

[super@LantronixVLM]# config slv http ltrxtest
[config slv http ltrxtest]# ?
SLV HTTP config options are:
url url

Use the url subcommand to specify a target. Both IP addresses and hostnames can be used. However, hostnames require configuration of DNS.

[config slv http ltrxtest]# url
[config slv http ltrxtest]# exit

You can view your test with the show slv command.

[super@LantronixVLM]# show slv http ltrxtest
slv http ltrxtest


Use the config slv tcp testname command to create a TCP test.

[super@LantronixVLM]# config slv tcp supportssh     
[config slv tcp supportssh]# ?
SLV TCP config options are:
host <host>
tcpPort <tcpPort>

[config slv tcp supportssh]# host  
[config slv tcp supportssh]# tcpPort 22
[config slv tcp supportssh]# exit


Use the config slv ipt testname command to create an IPT test.

[super@LantronixVLM]# config slv ipt voiptest
[config slv ipt voiptest]# ?
SLV IPT config options are:
call type < sip >
codec < g711u | g711a | g728 | g729a | g729e >
destination ip <destination ip>
duration <1-600>
payload < harvardfemale | harvardmale | dtmf1 | dtmf2 | dtmf3 | dtmf4 | dtmf5 | dtmf6 | dtmf7 | dtmf8 |
 dtmf9 | 1khz | 2khz | 3khz >

[config slv ipt voiptest]# call type sip
[config slv ipt voiptest]# codec g711a
[config slv ipt voiptest]# destination ip
[config slv ipt voiptest]# duration 15
[config slv ipt voiptest]# payload harvardfemale
[config slv ipt voiptest]# exit

A separate Local Manager can be used as an IPT endpoint. To configure it, see IPT Listener.

Scheduling SLV Tests

SLV tests are run by the SLV monitor, which is similar to other monitors such as modem, gps, and chassis. SLV monitors take two arguments:

  • SLV test - required, specifies which SLV test to run
  • Rule(s) or Ruleset(s) - optional, take action based on SLV test results

Use the config monitor slv command to schedule a monitor.

Here is the syntax:

[super@LantronixVLM]# config monitor slv
usage: monitors <slv {testName} | system> {ruleList} {:[delay seconds]}

ruleList - rule names separated by comma or bar
delay seconds - time between executions
ex. config monitors slv httpTest rule1, rule2 | rule3 :30

For example:

[super@LantronixVLM]# config monitor slv ltrxtest
Validate scheduled monitor(slv)?  (This will execute the job now.) (y/n): y
Job was scheduled 1: [Interval: 00:00:30 Mask: * * * * *] rulesMonitor slv ltrxtest 30

The above example schedules the ltrxtest (HTTP test) we created earlier. The config monitor slv command does not need to be told what type of SLV test you are using.

Viewing SLV Test Results

CC: Inventory > Local Manager Summary > SLV Stats

Use the show slv stats command to view collected stats on SLV tests.

Here is the syntax:

[super@LantronixVLM]# show slv stats
usage: stats <testName> [options]

--- options ---

  -n <count>  Maximum number of events
  -v          Verbose display
  -x          Execute now

To view the stats of the HTTP ltrxtest test we scheduled earlier, run show slv stats ltrxtest.

[super@LantronixVLM]# show slv stats ltrxtest
CDT    Test        IP Address   Connect  1st Byte  Last Byte  # Bytes  HTTP Response  Message
-----  ----------  -----------  -------  --------  ---------  -------  -------------  -------
09:22  ltrxtest  7        388       470        300691   200 OK                
09:21  ltrxtest  8        348       415        300686   200 OK                
09:21  ltrxtest  8        363       428        300681   200 OK                
09:20  ltrxtest  8        453       3679       300706   200 OK                
09:20  ltrxtest  12       463       3804       300691   200 OK                
09:19  ltrxtest  15       422       515        300706   200 OK

Adding Rule(s) and Ruleset(s)

CC: Inventory > Inventory Group > Automation > Rules CC: Inventory > Local Manager Summary > Automation > Rules

To take action based on the results of SLV tests, we'll need to create some rules that look at the collected data.

In this example, we will create a rule that triggers on a maximum time to connect. If the time to connect exceeds the threshold, we'll create an alarm.

[super@LantronixVLM]# config rule ltrxslow
[config rule ltrxslow]# conditions   
[config rule ltrxslow conditions]# slv.timeToConnect max 7       
[config rule ltrxslow conditions]# exit
[config rule ltrxslow]# action alarm -a "Lantronix website is slow"
[config rule ltrxslow]# exit


If you are unsure which actions and variables are available for rules, consider using the Control Center's Rules pages, as they list all of the options in convenient drop-down menus.

To apply the rule to a new or existing SLV monitor, use the config slv monitor command.

[super@LantronixVLM]# config monitor slv ltrxtest ltrxslow
Validate scheduled monitor(slv)?  (This will execute the job now.) (y/n): y
Cancelling previous monitor for 'slv ltrxtest'
Job was scheduled 2: [Interval: 00:00:30 Mask: * * * * *] rulesMonitor slv ltrxtest ltrxslow 30

You can see if the rule's condition was met by running show alarms.

[super@LantronixVLM]# show alarms
CDT       Elapsed     Device     Context         Message                 
-----     -------     ------     -----------     ------------------------
09:34     0:28                   ltrxtest        Lantronix website is slow

IPT Listener

If there are no IPT endpoints in your network, you can still use the IPT tests by turning on the IPT Listener feature on your Local Manager.

Use the config system ipt command to enable the listener.

[super@LantronixVLM]# config system ipt
[config system ipt]# ?
Allowable arguments are:
[no] subinterface
[no] listen
[no] allow
[no] deny
or 'exit' to quit config mode

[config system ipt]# listen <-- REQUIRED to enable listener
[config system ipt]# payload harvardmale
[config system ipt]# allow all
[config system ipt]# duration 15
[config system ipt]# exit