Hi,
In the our company Skype use for external communication.
But recently we have problem with it, because MS changed a way how client Skype work.
Dynamically IPs now used for client Skype work, which categorized by Web Filtering as "Internet Telephony".
It's right, but "Internet Telephony" category blocked in our company.
I suggest to create new category "Skype" or "Internet Telephony - Skype", like it was made for "Social Web"
http://www.websense.com/support/article/kbarticle/URL-Category-Set-Update-Early-2013
It will make possible to control Skype App more accurately.