After you integrate BIG-IP® Global Traffic Manager™ (GTM™) into a network with BIG-IP Local Traffic Manager™ (LTM®), or vice versa, the BIG-IP systems can communicate with each other. If Access Policy Manager® (APM®) is also installed on one of the BIG-IP systems with LTM, APM calculates virtual server scores and provides them to GTM.
The calculation is based on the number of active access sessions. APM calculates two usage scores and assigns the higher of the two to the virtual server:
A value of 0 indicates no capacity and a value of 100 means full capacity available on the device.
Use a GTM global load-balancing pool for GTM to load balance APM users based on the virtual server score. GTM uses virtual server score in the VS Score and Quality of Service load balancing methods for global load-balancing pools.
These tasks must already be complete before you begin.