Week 4 Assignment # 1 (topologies)

A Mesh topology is a style of connecting computers in a network in a fashion where every link has a redundant path. A mesh topology is also known as a self healing network in that if a segment of the network fails for what ever reason then the data can still be transmitted across another linked path. This would include possibly hoping across a few extra network segments to reach the destination but it would be able to do it. This redundancy of course comes with a price for the extra pathing that would be incurred to ensure that every node will be able to see every other node.

A bus topology was one of the first topologies used in that it consists of a single bus (aka: backbone). Typically this is a coaxial cable where nodes can connect via a ‘T’ connector which allows the bus to continue to the end of the cable. Due to the nature of this design when the data reaches the end of the cable if it’s not properly terminated (which kills the signal) then we can receive what’s called bounce back. This ricocheting of the data could severely hinder the communication pathing of the bus. As I recall there is a general rule of thumb for a bus topology which is the rule of 5-4-3-2-1. This means that you can have 5 data segments of which there can be 4 connectors (continuing connections) which link the 5 data segments. 3 of the segments must be populated. There must be 2 terminators on the bus (1 at each end of the cable) and 1 network connection out.

A ring topology is similar to a bus topology except that the bus is in the form of a circle and every node on the ring can only connect to the neighboring node. There is no beginning and no end to a ring topology which gives it its name of ring topology. Since every device on the ring can only talk to its immediate neighboring node on the ring if that neighboring node is offline or cannot communicate then there is a break in the ring and data basically comes to a stop. A ring topology is also known as a token-ring which means that there is a token which is passed from node to node. A node can only put information on the ring if it has the token. Once a node places data on the ring and it’s done sending the data then it passes the token on to the next node. It is possible for there to be multiple tokens flying around on the network at one time. Ring topologies can carry large payloads of data.

The last topology which seems to be more prevalent in today’s small, medium and large network configurations is a Star topology. A star topology is where a group of computer nodes connect directly to a central point on the network. This central point can be a hub, switch, or a router. By this type of connection it creates an image of a star. A good point to this type of setup is that each computer is on its own hardware segment of the network. If something fails it’s fairly easy to troubleshoot and the fault doesn’t usually take down the entire network. This is true unless the central point of the network such as the hub, switch or router itself fails. In a star topology, many times there are multiple star segments which hang off of each other. This way it creates a form of a star but also a tree type effect of the smaller star networks. Hubs usually connect up to the switches and the switches usually connect up to other switches which connect to routers which join networks together.

Ethernet is the medium which connects computers together in a local area network configuration. Ethernet allows computers to communicate at the MAC address