Local area networks (LAN) are extremely popular in both the consumer and enterprise markets. The LAN has become ubiquitous throughout both of these markets as the Internet has grown in size and use, PCs have become readily available at an attractive price point, and high-speed broadband connections have become readily available. Yet, with all the usage of LANs for connecting computer equipment of all types, there is no standard, formal industry accepted definition for a local area network (Comer, 2006, 15). According to the Institute of Electrical and Electronics Engineers (IEEE), a local area network is describes as being “distinguished from other types of data networks in that they are optimized for a moderate-sized geographic area, such as a single office building, a warehouse, or a campus” (2001). Some definitions include a distinction concerning physical proximity (Palmer & Sinclair, 2003, 2), while others provide definitions based on topology, physical medium, or performance characteristics. Vendors, governing/standards bodies, and even network managers have yet their own definition of the exact meaning of what a local area network is and means. These definitions tend to use terminology loosely and allow the end user to determine actual meaning based on context and technologies used. The following discussion will give the reader the foundational information of LANs, including LAN addressing (both MAC and IP addressing), architecture, and protocols.
Key Terms in this Chapter
TCP/IP Network Reference Model: An open model used for discussions of networking using the TCP/IP suite of protocols.
Ethernet: A family of LAN specifications that has become the de facto standard for local area networks.
LAN Segmentation: The process of dividing media access/collision domains via physical devices (bridges, switches, routers) and/or logical means (virtual local area networks)
OSI Network Reference Model: An open framework used for discussions of local area network operations and protocols in logical, layered approach developed by the ISO.
Collision Domain: See Media Access Domain
Media Access Domain: The network components that share bandwidth on the local area network and contend for access to the local area network using CSMA.