Need high frequency ping checks

Hello,

At my organization, our requirements for monitoring our clients' WAN interfaces is to ping them once per second.

I am using Nagios version 2.10.

I have set the interval_length in nagios.cfg to 1.  It pings once per second for the most part, however there are 20-25 second periods when it doesn't ping anything.  Is there any way to have Nagios check hosts' status consistently once per second?

I am including relevant nagios.cfg entries below.

Thanks for your help,

Todd

SLEEP TIME

#sleep_time=1
sleep_time=1

SERVICE INTER CHECK DELAY METHOD

#service_inter_check_delay_method=s
service_inter_check_delay_method=n

MAX SERVICE CHECK SPREAD

max_service_check_spread=30

SERVICE INTERLEAVE FACTOR

#service_interleave_factor=s
service_interleave_factor=1

MAX CONCURRENT CHECKS

max_concurrent_checks=0

SERVICE REAPER FREQUENCY

#service_reaper_frequency=10
service_reaper_frequency=1

HOST INTER CHECK DELAY METHOD

#host_inter_check_delay_method=s
host_inter_check_delay_method=n

MAX HOST CHECK SPREAD

max_host_check_spread=30

INTERVAL LENGTH

#intevel_length=60
interval_length=1

AUTO RESCHEDULE CHECKS

auto_reschedule_checks=

auto_reschedule_checks=0

AUTO RESCHEDULING INTERVAL

auto_rescheduling_interval=30

AUTO RESCHEDULING WINDOW

auto_rescheduling_window=180

USE AGRESSIVE HOST CHECKING

use_agressive_host_checking=