off-channel scan and voice traffic

Off-channel scan is in an important operation, where the AP collects information about the specific area where it is mounted. It will report sources of interference, different SSIDs implemented on each channel, duty cycle etc. This information is useful for dynamic RF module developed by each vendor and wireless intrusion detection/prevention system (WIDS/WIPS). The idea … Continue reading off-channel scan and voice traffic →

unicast key rotation

In WPA/WPA2 Personal Wi--Fi networks, the only element responsible for security is a preshared key (PSK), which in fact is a pairwise master key (PMK). In a process 4-Way Handshake, both the mobile client and AP generates dynamic keys without sending a preshared key in the air. Every association between AP and mobile client must … Continue reading unicast key rotation →

802.11k

One of the problem with today's Wi-Fi operations is a fact the mobile client is a device, which makes a decision when and why to roam to a different Access Point. The most important factor to make such a decision is the Received Signal Strength Indicator (RSSI). If the mobile client's sginal will drop to … Continue reading 802.11k →

null probe request

There are 2 types of scanning: passive scanning - mobile client will listen to predefined channels for beacons and active scanning - mobile client will send a probe request frame asking for specific Wi-Fi network it had been previously associated or all available Wi-Fi networks on specific channel. I will focus on the second option. … Continue reading null probe request →