SSID Full Form

Service Set Identifier(SSID) is used to identify any 802.11 Wireless Local Area Network (WLAN). It is also used by clients to identify and connect to the particular Wireless Network. To discuss in layman’s terms, it is the SSID we see when we are trying to connect your device(phone/computer) to a Wireless Network. Below is an screenshot that shows the SSID’s available while browsing for available networks to connect. It can be a 32 character string which is case-sensitive and can contain letters, numbers, symbols, punctuation marks and even a blank space. The following six characters are considered invalid characters in an SSID:

/, ",  +, ], TAB, trailing spaces 

And the first character cannot be any of:

!, #, ;  

Types of SSID :

1. Hidden – The SSID will not be visible for all the clients. Only the user who is aware of the exact SSID can jump on that Wireless Network.
2. Broadcasted – The SSID is broadcasted over the network. Anyone can find that network and hop on.

Characteristics :

1. SSID helps distinguish one network from other networks.
2. An SSID can be broadcasted in either 2.4GHz or 5GHz.
3. Each SSID can have its own security in place with either open, WEP, WPA, WPA2, etc…
4. A Guest SSID may allow users to connect to the Internet but not to other local devices or facilities like intranet.
5. An SSID can be analogous to a Virtual LAN(VLAN) to segment traffic or to provide different facilities or access levels.

Advantages :

• In multiple Wireless Network Environments it would be chaotic to send and receive data. To avoid this, the SSID is included in each packet that is sent over a Wireless Network
• It ensures that the data being sent over the air arrives at the correct location.
• Helps differentiate WLANs from one another
• Roaming is efficient if the SSIDs of both the WLANs are same.
• A single Access Point can broadcast multiple SSIDs at the same time. It will help in logically diving Users(For Example: In a School Environment, a single SSID can be used by all the Teachers and a different SSID can be assigned to all the Students, each with different policies and functions.).

Disadvantages :

• Though security is added with hidden networks, it is still easy to hack
• While encryption is strong, most people use trivial passwords and access would become easier
• Any attacker can broadcast an SSID with the same name as our’s and steal our personal information
• An attacker can also spoof the “disassociation frame” as it came from the wireless bridge and send it to one of the clients connected; the client immediately reconnects revealing the SSID.