As a starting point, you'll need to profile your traffic mix, you should know what type of function you use skype for :- Voice, Video, Messaging etc, etc Repeat this for a cross section of users so you get a general picture across the business. The Microsoft site will tell you what the bandwidth requirement is for each type and you can then extrapolate the bandwidth for a given traffic profile. Apply some QOS to match not forgetting to factor some growth/ spike into the equation.   Nino ... View more