Cisco WLCOR 350-101 key terms

Received Signal Strength Indicator: the measured power level of a received radio signal, shown in dBm or as a relative scale. It shows how strongly a radio hears a peer, but not how much interference is present.

Signal-to-noise ratio: the gap in decibels between the received signal and the noise floor. A larger gap lets the receiver use faster modulation and coding, so SNR predicts achievable data rate better than signal strength alone.

The level of background RF energy in an environment, measured in dBm. Interference sources raise it, and it sets the lower limit below which a client or access point cannot reliably decode a signal.

Effective Isotropic Radiated Power: the total power a radio system appears to radiate, combining transmit power, cable loss, and antenna gain. Regulatory rules cap it, and matching EIRP on both ends keeps a link balanced.

The same signal arriving at a receiver by several routes because it reflects off walls, floors, and objects, each copy delayed and phase-shifted. It causes fading and intersymbol interference, but MIMO also exploits it.

An elliptical region around the straight line between two antennas that should stay mostly free of obstructions. Blocking it weakens the signal even when the antennas appear to have clear line of sight.

Multiple-input, multiple-output: using several antennas at each end to send parallel data streams or to add diversity. It is the main reason 802.11n, ac, and ax deliver far higher throughput than earlier standards.

Interference caused by two nearby radios transmitting on the same channel so their frames overlap. Clients must wait or retransmit, so airtime is wasted; it is reduced by channel planning and power control rather than eliminated.

A desktop survey that models floor plans, wall attenuation, and antenna patterns in software before hardware is installed. It estimates access point count and placement, and is later validated by an on-site survey.

An on-site survey where an access point is temporarily placed at candidate locations and the area is walked with a measuring client. It uses real building attenuation instead of modeled walls to confirm coverage and roaming boundaries.

A color-coded floor plan overlay showing predicted or measured signal strength, SNR, or data rate. It makes coverage holes, weak overlap, and excessive power easy to see at a glance.

Assigning the same channel to access points whose coverage cells do not meaningfully overlap. A well-planned reuse pattern keeps co-channel neighbors far apart while allowing only three non-overlapping 2.4 GHz channels.

Two goals a design must balance: coverage means a usable signal everywhere users work, while capacity means enough airtime and channels for the expected devices. Dense areas need smaller cells and more access points.

Control and Provisioning of Wireless Access Points: the protocol that carries control traffic, and optionally client data, between lightweight access points and a wireless controller. It uses UDP, with DTLS protecting the control channel.

An architecture that divides 802.11 work between the access point and the controller. Time-sensitive tasks such as beacons and acknowledgments stay in the AP, while authentication, mobility, and policy live in the controller.

An access point that relies on a wireless controller for configuration, software images, and much of its 802.11 management. It joins the controller over CAPWAP and normally sends client traffic through it.

An access point mode that lets a branch AP switch client traffic locally while still receiving configuration and authentication from the central controller. Local traffic keeps working if the WAN link to the controller fails.

Cisco's current wireless controller family, offered as an appliance, a virtual machine, or a cloud service. It runs IOS-XE and manages lightweight access points through model-driven, intent-based configuration.

Controller software that runs on a Catalyst 9000 switch or an access point instead of a separate appliance. It manages lightweight APs with the same policies as hardware controllers, suiting small and branch sites.

The roles an access point can take, such as local (serving clients), monitor (passive scanning and rogue detection), sniffer (capturing frames for analysis), or FlexConnect (local switching at a branch).

A client leaving one access point and reassociating with another. Layer 2 roaming stays within one subnet; Layer 3 roaming crosses subnets and needs mobility tunneling to keep the client's address and session alive.

A standard where the access point supplies a neighbor report listing nearby APs and their channels. The client scans only those channels, cutting the off-channel time that delays a roam.

A standard that lets the network influence client behavior, notably BSS Transition Management frames that suggest a better access point, plus load and network information. It helps move clients off weak or congested radios.

Fast BSS Transition: a standard that lets a client set up keys with a target access point before leaving the current one, shrinking the authentication exchange at roam time. Voice and latency-sensitive clients benefit most.

Opportunistic Key Caching: a method where a client roaming between access points on the same controller reuses cached key material instead of running a full 802.1X authentication. It speeds roaming but is slower than 802.11r.

Cisco Centralized Key Management: a proprietary fast-roaming method in which the controller caches keys and delivers them to the new access point, letting the client skip a complete 802.1X exchange during the roam.

A feature that nudges dual-band clients to associate on 5 GHz or 6 GHz instead of the crowded 2.4 GHz band, often by delaying probe responses on 2.4 GHz. It raises capacity without any client-side change.

A set of controllers configured to share access point and client information so clients can roam between them, including across subnets using mobility tunnels. WLAN and security settings must match across the group.

Port-based access control where a client, an authenticator (the controller or AP), and a RADIUS server exchange EAP messages. The client must authenticate before it is allowed to send ordinary user traffic.

Extensible Authentication Protocol: a framework carried inside 802.1X that supports methods such as EAP-TLS with certificates and PEAP with a server certificate plus user credentials. The chosen method decides what the client must hold.

A AAA protocol the controller uses to pass credentials and authorization attributes to a central server such as Cisco ISE. The server's response decides whether the client is admitted and which policies apply.

Simultaneous Authentication of Equals: the WPA3 password handshake that resists offline guessing because each attempt requires a live exchange with the access point. It replaces the WPA2 personal pre-shared key handshake.

Adaptive Wireless Intrusion Prevention System: a controller feature that watches 802.11 management and control traffic for attacks such as deauthentication floods, honeypots, and spoofed frames, raising alarms or taking protective action.

Radio Resource Management: the controller feature that assigns channels and transmit power to access points, balances clients across radios, and reacts to changing interference. It replaces static plans in most enterprise deployments.

Cisco's spectrum intelligence feature, using dedicated hardware in the access point to detect, classify, and locate non-Wi-Fi interference such as microwave ovens, Bluetooth headsets, and wireless cameras.

Finding unauthorized access points by scanning for beacon frames and comparing them with the known managed devices on the network. Detected rogues can be classified, located, and optionally contained.

An access point mode that captures 802.11 frames on a channel and forwards them to a controller or remote analyzer instead of serving clients. It is the main tool for diagnosing retries, authentication failures, and roaming.