What Is an SSID?by Jared PaventiUpdated September 28, 2017
The rapid ascent of wireless Internet as a means of connecting to the World Wide Web has led to an increase in the number of people hosting a wireless signal. Wireless Internet access points can broadcast signals with a range of up to 120 feet, meaning that users in neighborhoods, apartment buildings, commercial parks and other areas with large concentrations of people can see multiple networks. These networks are called service set identifiers (SSIDs).
The "service set" in service set identifiers refers to the network the computer is attempting to reach. These networks are referred to as wireless LANs, or wireless local area networks. This is typically the setup in a residential or small business application. An Internet service provider brings the Internet into the building and connects it to a modem. The modem has a piece of cable that is connected to a wireless router. This router distributes the signal to users. The word "identifier" in service set identifiers refers to the name assigned to the network.
A basic SSID is actually a set of ASCII (American Standard Code for Information Interchange, a universal computer language) characters that is unique to a particular wireless router. This basic identifier is usually the router's MAC (Media Access Control) address. A MAC address is a unique set of code assigned to any Internet or network gateway. For instance, the modem and router provided by an Internet service provider and the wireless access point each have separate MAC addresses. In addition, the wireless receiver card in an individual computer also has a MAC address and SSID. The vast majority of routers on the market today support enhanced SSID, which allows a name to be assigned to the network. This allows a user at an establishment with free wireless Internet to access service by the name of the network, rather than by using a 32-digit code.
SSIDs are typically assigned during the setup process of the router or wireless access point (WAP). Consumer-grade WAPs and routers have setup functions that can be run at installation. For example, the default name for Linksys brand routers is "linksys." Many people name their access points with their own last names or the names of the businesses for which the networks were created. Creating a unique name is essential for ease of use and a steady connection.
Just because an SSID is broadcast to a user does not mean that user can connect to that particular network. A computer's wireless software may find multiple networks in close proximity, but there is a very good chance that the network's owner has security measures in place to restrict access. For many, this is to protect "wireless poachers," or people who steal their neighbors' Internet connection without paying for their own. By password-protecting networks, users also prevent others from accessing files on their network.
Manufacturers of routers and WAPs have introduced a feature that allows users to disable the broadcast of the SSID. On the surface, this seems like an effective security tool to prevent people from poaching broadband. However, stopping the SSID broadcast does not stop the signal from being circulated. Sophisticated computer users have been able to get around this block. The individual computer's wireless access card has its own MAC address and SSID, and users typically do not secure them. The potential exists that an outside user could find this SSID, enter the computer without using a password and either have access to the computer's contents or its Internet connection. Therefore, IT professionals do not recommend this as the only level of network security.