Can anyone let me know how I would reduce time between Last Check Time and Next Scheduled Check on a particular service. I have a very critical task to monitor and the time between checks is currently 5 minutes, which is too long for this service. Can I reduce that time? I need this to be 1 minute or even 30 seconds.

I want Nagios to check this service every 30 seconds. I currently have defined the service as follows:

define service{
        use                     local-service
        host_name               OpenSIP,test-RTSIP
        service_description     SIP Registration
        check_command           check_nrpe!check_sipreg
        check_freshness         0
        freshness_threshold     900
        active_checks_enabled   1
        passive_checks_enabled  1
        }