Ch.6 DATA COMMUNICATION

       This chapter basically covers how and what is used to communicate online and through different types of networks. A network is the collection o computers that communicate with one another through transmission lines or wireless. An example of LAN would be like the computer lab at the business lab. All the computers are connected to a single location that students can access onto a single LAN since it is in the same geographic location. The WAN or wide area networks would be used for big corporations that are located in different geographic locations. Other types of internet connections would be a DSL modem which translates to a digital subscriber line. They operate on the same lines as voice telephones. I used to have DSL AOL and it seemed that it would take longer to connect to the internet. The better alternative would be to have a cable modem connected to a wireless router. They provide high speed data transmission using cable television lines. This is one of the most popular choices amongst households. Ex: Comcast installs a fast, high capacity optical fiber cable to a distribution center in each neighborhood that it serves. This is the more popular choice because when a household connects the cable into the wireless modem to a router, every person living in the household can connect to the internet with a relatively high speed. VPN is a virtual private network that creates an appearance of a private connection. A tunnel is the virtual private pathway over a public or shared network from the VPN client, VPN communications are secure because the client software encrypt, or codes so that the contents are protected from spammers. There are pubic or private keys on the internet. There are the public keys which encodes messages and private keys that decode them. Secure communication over the internet uses a protocol called HTTPS where data is encrypted using a protocol called the Secure Socket Layer. It is also beneficial to create firewalls on your computer to prevent unauthorized network access. A perimeter firewall is outside the organizational network and internal firewalls are inside an organizational network.