Skype does not need very much bandwidth when video is not used, so I doubt it. It's impossible to say now what your Skype problem was. Wrong recording device chosen in Skype settings, for instance, would cause the issue you described.
All applications sending and / or receiving audio and video belong to those that use this reserved bandwidth. If it's not available, for instance because you are downloading something, application still mostly works using bandwidth which is available. My recommendation is that if you have an VoIP application you use regularly, or if you do video chat often, leave this as it is, to be sure. Especially if your connection is not very fast.