Hello Reinhard
Subscriber templating is part of Cisco’s Intelligent Services Gateway (ISG) template-based policy and feature provisioning which is designed to improve CPU utilization.
Traditionally, ISG subscriber policies were provisioned individually as separate features. However, because most sessions shared common policies, a more efficient approach is to create templates to improve CPU resource usage. If you’re not using ISG features, then there is no need to worry about this particular command.
The subscriber templating command in your Cisco 4321 by itself has no impact on the operation of the router itself, so whether you have it on or off makes no difference. The difference exists when you actually apply the templates. For more information on how to apply them, take a look at this Cisco documentation:
The truth is, there is very little documentation about this for the 4321. I haven’t had direct experience with the subscriber templating feature on that platform, so I can only assume that it is similar to the ASR as described in the documentation above.
I hope this has been helpful!
Laz