3. How does network address translation present problems with collaboration? How are these problems solved?
NAT blocks users from connecting directly to each other when one of the computers is in a different network. You cannot even see or reach the other computers. The only existing answer is to use a server with a fixed IP address to build the connection between the computers. Well-designed applications can use the server to build “holes” through the NAT to connect directly to other computers. Microsoft has created several “servers” for each of their products to help solve these problems. It is not yet clear if they are “well-designed” and use the “holes” approach (see the MIT document), or if they rely on the server to relay all of the traffic—resulting in a heavy network load on the server.