Skype Phone
Using my DD-wrt router and a bandwidth monitor that works with the router, called Rflow, I measured how much bandwidth the Skype phone uses. It uses anywhere between 5 to 10 KBps. Checking the Skype website they say the Skype service uses 3-16KBps (link). Just as a side note it is possible for Skype to use all of your bandwidth. From Wikipedia:

“Skype also routes calls through other Skype peers on the network to ease the traversal of Symmetric NATs and firewalls. This, however, puts an extra burden on those who connect to the Internet without NAT, as their computers and network bandwidth may be used to route the calls of other users.”

Here is my results in a nutshell. At a bandwidth usage of 5-10KBps of up and 5-10KBps down The Skype call came through clearly. I have Comcast cable in the Philadelphia area and I only get 40KBps up. So Skype is using a 1/4 of my up bandwidth. I then share that connection with 4 other people. So that explains why I am unable to make Phone calls some times.

Look for my final write-up later this week.