DLUs = Device License Unit
depending on the phone model how many they use, you need to contact pre-sales or licensing for them
if you don't have the DLUs you cannot add phones
the SKU from each phone entitles you to the necessary DLUs for that phone but DLUs can be purchased separately
you also need a node license to activate the CCM service if 5.x and an extra feature license if running 6.x
you can look "licensing" on cco and will get more info
HTH
java
if this helps, please rate
HTH
java
if this helps, please rate