Citrix Systems Network Router 9.2 User Manual

For many NetScaler features, policies control how the feature evaluates data, 
which ultimately determines what the feature does with the data. A policy uses a 
logical expression, also called a rule, to evaluate requests, responses, or other 
data, and applies one or more actions determined by the outcome of the 
evaluation. Or a policy can apply a profile, which defines a complex action.

Some NetScaler features use advanced policies, which provide greater 
capabilities than do the older, classic, policies. If you migrated to a newer release 
of the NetScaler software and have configured classic policies for features that 
now use advanced policies, you might have to manually migrate policies to the 
advanced-policy format. 

Classic policies evaluate basic characteristics of traffic and other data. For 
example, classic policies can identify whether an HTTP request or response 
contains a particular type of header or URL. 

Advanced policies can perform the same type of evaluations as classic policies. In 
addition, advanced policies enable you to analyze more data (for example, the 
body of an HTTP request) and to configure more operations in the policy rule (for 
example, transforming data in the body of a request into an HTTP header).

In addition to assigning a policy an action or profile, you bind the policy to a 
particular point in the processing associated with the NetScaler features. The bind 
point is one factor that determines when the policy will be evaluated.