If it's internal the Web Rules no longer apply as there is a permanent connection while the software is running and while the actual data transfer is short the connection remains intact till it's broken by the user.
As Ben said it depends on the type of CAL being used but if you only had the 1 Windows Server then most times whoever sells the CAL's sells the Server Type. Well with any that I deal with at least.
The Device Type are only used here by organizations with several Windows Servers as it saves them a lot of money. However if the company only has the 1 Windows Server they tend to buy the Server CAL's as they are cheaper initially.
The link to M$ CAL Licensing is probably the best explanation available but even then it can be confusing and you really need todays Interpretation by M$ to decide what the rules are today.
It also depends on who you talk to at M$ as I keep getting different Opinions but I'm not the average User of CAL's as I sell them to different Companies when I setup their Servers.
Col