Network Design Proposal
This paper will provide the recommendations for a network that will allow the connection of 50 different remote locations. Half of the remote locations will be required to connect with central headquarters 6 to 8 hours a day and send large files back and forth which consist of date, graphics and product design information including blueprints. The other 25 locations are sales offices and connect at the end of the day to upload daily/other periodic reports that total less than 5 megabytes of data. With the given research I have gathered, I recommend the following:
LAN Each of the 50 LAN within the remote locations does not have a criteria within the question posed. A few things are taken as assumptions. The first assumption is that the 25 remote locations does not only need to have the ability to send files from to the central headquarters 6 to 8 hours a day but that it also needs the ability to send these files among themselves. The network requirements also states that the other 25 locations only needs to connect to the central headquarters at the end of the day and upload files less than 5 megabytes to the central site.
The second assumption is that at no point the sales site could convert to a site that would require the ability to send videos and other large files to each other. With these assumptions, I recommend the LAN to use an Ethernet protocol for the 25 sales sites. This protocol is the most widely used protocol as of today (Martin W. Murhammer, 1999). Ethernet is the most cost effective method to employ over the LAN network for the requirements given. Ethernet provides the equivalent to hitting a fly with a fly swatter, instead of using a mallet which would be done by using WAN protocols such as frame relay and ATM.
Because this network would use a bus topology, we will use the access method of CSMA/CD to prevent packet lost (Martin W. Murhammer, 1999). This access method will allow computers to use the same transmission line and take turns sending information along that line. For the other 25 sites’ LAN, I recommend using the Token Ring Protocol. With the given criteria of staying connected to the central office, a main transmission line cannot be used. For the ability to stay connected, you would need a protocol that does not have to use the same transmission line for each computer to be able o get out to the WAN from the LAN. The LAN will have to use Multi-station access units to avoid the use sharing a single transmission line. WAN The recommendation for the WAN network could also be different between the two divisions of the locations. In order to connect to the central headquarters and upload date at the end of the day you would need a simple protocol so that packets are sent the more effective and quicker route. The assumption that is taken about the WAN connecting to the other sites is that all data is held at the central headquarters.
I will also assume that there are servers located at all of the satellite sites to store data. I will assume data is off site at the central headquarters and can be retrieved at any site from a server at the central headquarters. In order to be able to connect to the central headquarters for 6 to 8 hours per day, you would need a protocol or connection with the ability to carry a lot of bandwidth. Circuit switching protocols can create a connection between the sites and the central headquarters. Circuit switching establishes a link between the two nodes that needs to be connected and send information back and forth.
Advantages to circuit switching are its fast and error free connections (Kolobe, 2006). In order to accomplish this with packet switching you must have a protocol instituted that allows error free and high speed connection between the routers of each location. A comparison of Frame relay and the ATM protocol is needed to decide on the best option for packet switching if that is considered. Frame relay is a standard when connecting multiple LANs together. When using frame relay, virtual circuits can exist simultaneously across a transmission line.
This allows each devise to use more bandwidth therefore the ability to work at higher speeds (Protocols). Frame relay uses error handling that discards erroneous packets to be retransmitted later instead of using time consuming error handling techniques (Protocols). The negative on this is that it further clogs the lines in the network causing more congestion and the need for more error handling controls. ATM protocol has a lot of advantages over frame relay. ATM is not tied to a specific medium and a specific physical medium (Greene, 2007). The ATM protocol is widely used for transferring large files that are a gigabyte in size.
This ability to transmit that size of data efficiently allows it to be the choice to transmit videos throughout the network. The third type of connection is a dedicated WAN connection or leased line. This is a permanent dedicated connection between two parties (Computer Network, 2009). The advantages of a dedicated line are the high availability and the ability to handle high data traffic between WAN’s. The disadvantage is the high cost of leasing each line that is needed (Computer Network, 2009). My recommendation is the use packet switching for the communications between the LAN’s.