What is SSID?

Definition

SSID stands for Service Set Identifier: the human-readable name of a wireless network, up to 32 characters, that devices display in their WiFi list. Multiple access points can broadcast the same SSID to form one seamless network, and a single access point can broadcast several SSIDs with different security and access rules.

One SSID, many access points

The SSID is a name, not a device. In a venue with several access points, all of them advertise the same SSID so a guest walking from the bar to the terrace stays on what appears to be one network while their device silently roams between radios. Fragmenting a venue into "Cafe-WiFi-1" and "Cafe-WiFi-2" breaks that, because devices cling to a weak association rather than switching. If coverage feels bad in a venue with plenty of hardware, duplicated or inconsistent SSID naming is one of the first things worth checking.

Separating guest and staff traffic

Good practice is at least two SSIDs on the same hardware: one for guests, mapped to an isolated VLAN with client isolation and the captive portal applied, and one for staff and payment devices with a strong passphrase and no portal. This keeps a compromised guest laptop away from the point-of-sale system and means portal changes never risk taking the till offline. Each SSID can carry its own bandwidth limits, so guest traffic cannot starve operational traffic during a rush.

Naming and hiding

Name the guest SSID after the venue so guests can identify it without asking. Hiding an SSID is not a security measure: the name still appears in client probe requests and is trivially recovered, while hidden networks cause connection problems on some devices. Use proper encryption and network segmentation for security, and keep the guest SSID visible and obvious.

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