Mesh, Bus, Ring, and Star are all types of a topology. Each of these types of topology is used for specific network's but some networks can uses any combination of the four. A mesh topology has each station connected to the others. This network is more difficult to set up but provides a great deal of performance and reliability. In a Mesh network if a segment of the network is broken, then the packet being sent will find an alternate route to its destination.

Mesh are used in Wide Area Networks (WANs) where reliability is important, this is used were the network is small. A bus network has a single cable that is the backbone of the system. Ethernet bus networks are relatively easy to install and do not require much cabling. Bus networks work best with a limited number of devices because if a cable fails the entire network effectively becomes unusable.

Ring topologies, all the devices on the network are connected to a common cable, which loops from device to device. Ring networks are implement in SONET and FDDI rings. Ring networks are very fast and simple network, however if any part of the ring goes down, the entire network is down. Star topology, each device has its own cable connecting the device to a common hub. The hub that is the central connection point of the network. A failure of a cable will only take down one device in the network and not the entire network but if the hub goes down the entire network is down.

Star networks are easy to implement and extend, even in large networks, and failure of a non-central device will not have major effects on the functionality of the network. This is way many companies use Star networks. Topologies remain an important part of network design. With the understanding of each type of topology, any one can design and build their own netwokEthernet, Token Ring, FDDI, and wireless are all types of protocol. These are a set of rules that govern the communication between devices on the network. Ethernet is a protocol is the mostly widely used.

The devices listen to the cable before sending anything through the network. Ethernet uses a bus or star topology and data transfer rates of 10 Mbps (10 Base-T Ethernet), 100 Base-T (Fast Ethernet) and 1 gigabit (Gigabit Ethernet). Token Ring, all devices are connected in a ring or star topology where one bit or token is passing scheme, this to prevent the collision of data between two devices that want to send messages at the same time. The Token Ring protocol is the second most widely used protocol and is still IBM's primary local-area network (LAN) technology (PC Tech Guide 2002).

Token Ring networks employ several mechanisms for detecting and compensating for network faults. Token Ring network is used with star topology, contributes to overall network reliability. Fiber Distributed Data Interface (FDDI) is a protocol that sending digital data over fiber optic cable. FDDI networks are token or bit passing networks and support data rates of up to 100 Mbps. FDDI networks are mostly used as backbones for wide-area networks (WAN). FDDI supports the transmission of voice and video information as well as data and can support several work devices on the network.

Wireless LANs use electromagnetic airwaves, either infrared or radio frequency, to communicate information from one point to another without relying on any physical connection. The advantage of wireless connection is mobility, the device is not link to a cable. Ethernet, Token Ring, FDDI, and wireless all types or protocols that help with engineering and design of the network. The TCP/IP protocols function at the Network and Transport Layers of the OSI model. For this reason, they are often referred to as Network and Transport protocols. The IP protocols function at the lower Network Layer by routing and relaying between workstations.

TCP function primarily at the next higher Transport Layer to provide for the reliability of the communication link.