w.TechnicalPDF.com Frames serve the same function as packets. They surround user data with addressing, error checking, and other protocol-related bits. The term "frame" is used in lower-level protocols, such as Ethernet, which is used for communicating within LANs connected to the same switch in the wiring closet. Packets refer to data configured for transmission between LANs and on the Internet by using TCP/IP. Using TCP/IP as a Linking Protocol Ethernet is a way for individual frames to access LANs and for computers to retrieve frames from local networks, whereas TCP/IP is used to tie LANs together and to route packets between networks as well as to and from the Internet. As the need arose to tie LANs together for e-mail and file sharing, compatibility between LANs from different manufacturers became a problem. The TCP/IP suite of protocols became a popular choice for overcoming these incompatibilities and for managing the flow of information between LANs. Routers were developed to send data between individual LANs, and between LANs and the Internet and other networks. Routers send packets to individual networks based on their IP address. IP addresses are assigned to individual networks and servers that run software applications. Software Defined Networks in LANs As more varied applications, data from storage networks, cloud data, and Internet traffic is transmitted across LANs, large organizations need to have more control over how various applications are transmitted. For example, video files and real-time transactions require a higher priority than for example, e-mail. www.TechnicalPDF.com In addition, IT managers are under pressure to keep the staff lean and productive. At the same time, they need the ability to quickly adapt to changes and to add and delete features and applications. This is often difficult with current local area network infrastructure where prioritizing traffic results in complicated management of that traffic. It may be difficult to add new services because of the need for backward comp