What is a SSID?

SSID, ellipsis for Service Set Identifier, is a name of a Wireless Local Area Network. Another name for it is the network name. It is usually an alphanumeric (meaning it has a combination of letters and numbers), with a maximum of 32 characters and is case sensitive. All wireless devices that are to be part of a given network must employ a particular SSID in order for them to communicate with each other. The nomenclature helps in excluding devices that do not have a similar SSID from a given network. Based on the vendor, the access points of WLAN may be configured with factory settings, or default settings. Access points from Cisco Systems, for example, have a default SSID called ‘tsunami’. Some network administrators set the access points to distribute SSID to other wireless devices around it, which is known as “broadcasting” SSID. If your access point is at default settings, and the access point is set at “Allow Broadcast of SSID”, some devices (authorized or otherwise) might automatically associate with your network.

There are those who believe that one can prevent unauthorized access by disabling the broadcast SSID feature. This method is ineffective, because in the process of reconnecting to the network, the user will have to enter the correct SSID in order to access, and an eavesdropper can then use some sniff (using something like Kismet) out the SSID which will be transmitted in clear text, and then access the network himself. Most NETGEAR products with the site survey feature can help you look for networks SSID’s. Actually, the SSID itself is not a very strong feature, and for enhanced security, needs to be used in conjunction with other security measures like Wired Equivalent Privacy (WEP) or Wi-Fi Protected Access (WPA), the latter being the most accepted .

There are two kinds of SSID. These are Extended Service Set Identifier (ESSID) and Basic Service Set Identification (BSSID). The difference between the two is that ESSID requires an access point whereas, BSSID, which is really an ad hoc SSID, doesn’t. When considering which SSID is best for you, consider the following:

  1. Many companies like having their names as the SSID for their public WLAN’s. It would be ill advised to do that for a private WLAN though, as malicious elements may relish launching a denial of service attach against the owners of the network.
  2. A scrambled SSID (that is, one using characters such as d*&%$#G?!!) may again prompt a presumptuous hacker to do something unpleasant to your network, if he decides that you could be hiding something. In addition, such characters make network administration unwieldy. Not many people can remember an SSID which looks like d*&%$#G?!! off the top of their heads.
  3. Perhaps the best solution is to use a pseudo name. It makes it difficult for others to guess your SSID, and in addition, your network doesn’t give away your identity.

Choosing SSID calls for careful consideration on how it will affect the effectiveness of your WLAN in terms of manageability, security and functionality.

Additional Reading on SSID’s