One network type that is growing in popularity is the small office/home office (SOHO) network, which generally includes less than 10 PCs and may not include servers at all. Network resources such as DNS server resolution and e-mail servers are generally located offsite, either hosted by an ISP or at a corporate office. Internet access for the SOHO network is usually provided by cable, DSL, or perhaps ISDN. The boundary between the LAN and the WAN connections is an inexpensive router, frequently costing less than $100.

This router may also serve double duty as a firewall to shield the SOHO network from malicious activity originating outside the network. On the LAN side of the network, either a workgroup hub or low-end switch may be used to provide interconnections between client PCs and the router, and many routers include an integral hub or switch. Due to its simplicity, Ethernet is generally the LAN standard used to wire the SOHO network. Wireless standards such as 802.11b are starting to appear for the SOHO market, eliminating the need for adding LAN wiring in the home.

The IP suite of protocols is used for communications on the Internet. In addition to the IP, a requirement to support other protocols used in the corporate network, or to provide local communication in the SOHO network, may exist. In later chapters, we will discuss how this complex environment might be supported. In some instances, when a small office needs to connect to a corporate environment in a secure manner, some sort of VPN device is either built into the router itself or on the LAN. Below figure shows an illustration of a SOHO network.