media access unit การใช้

• Token ring is a logical ring topology, but is wired as a physical star from the media access unit.
• Rings can be unidirectional, with all traffic travelling either clockwise or anticlockwise around the ring, or bidirectional ( as in Fiber Distributed Data Interface ( FDDI ), and Resilient Packet Ring . 802.5 networks-also known as IBM token ring networks-avoid the weakness of a ring topology altogether : they actually use a " star " topology at the " physical " layer and a media access unit ( MAU ) to " imitate " a ring at the " datalink " layer.