i-check for monitoring - what is it ?

Guys,

 

From the monitoring reference guide - BIG-IP_Local_Traffic_Manager__Monitors_Reference.pdf

 

There is a brief statement around "iChecks" -

 

FTP, SMTP, POP3, and IMAP monitors provide inherent iCheck functionality, which reduces the load on BIG-IP systems and improves sustained monitor performance. Additionally, iCheck functionality provides smoother performance characteristics as these monitors approach full capacity.

 

What functionality do iChecks impart?