Jeff, a customer, has a wireless network and has reported that the network traffic from the wireless access points seems high compared to the limited number of wireless devices used. Jeff believes…

WPA encryption requires clients to possess the correct pre-shared key or credentials before the AP will allow network access, preventing unauthorized users from successfully authenticating even if they can see the SSID.

Changing wireless channels affects interference and performance but does not restrict which users can connect to the network.

MAC filtering creates an explicit allowlist of hardware addresses on the AP, so only devices whose MAC addresses are pre-approved can associate with the network, blocking unknown devices regardless of whether they know the passphrase.

Changing wireless speed standards (e.g., switching from 802.11n to 802.11g) alters performance characteristics but places no access restriction on unauthorized users.

Disabling (hiding) the SSID provides only security through obscurity - the network is still visible to a wireless scanner and does not prevent an unauthorized user from connecting if they know the network name.