Cisco WLCOR: Wireless Core Technologies: key terms

Flashcards for this exam Cisco WLCOR: Wireless Core Technologies guide Class dates

• 1024-QAMModulation with 1,024 constellation points carrying 10 bits per symbol, introduced in 802.11ax.Intermediate
• 320 MHz ChannelThe widest Wi-Fi channel, introduced by Wi-Fi 7 and available only in 6 GHz.Intermediate
• 4096-QAMModulation with 4,096 constellation points carrying 12 bits per symbol, introduced in 802.11be (Wi-Fi 7).Intermediate
• 6 GHz BandThe 5.925-7.125 GHz band (up to 1,200 MHz) opened to Wi-Fi 6E and Wi-Fi 7 in the US in 2020.Foundational
• Access CategoryOne of four WMM traffic queues: voice (AC_VO), video (AC_VI), best effort (AC_BE), and background (AC_BK).Intermediate
• AI-Enhanced RRMCisco RRM computed in the cloud with historical data via Catalyst Center to optimize RF over time.Advanced
• AirtimeThe amount of time on the shared medium consumed by a transmission or client.Intermediate
• Airtime Fairness (ATF)A feature that allocates airtime more evenly among clients or SSIDs rather than per frame.Intermediate
• Angle of Arrival (AoA)A location method that determines signal direction from phase differences across an antenna array.Advanced
• AP Join ProfileA Catalyst 9800 profile defining AP management settings such as CAPWAP timers, credentials, and SSH.Advanced
• Application Visibility and Control (AVC)Cisco deep packet inspection feature that identifies applications and applies QoS or drop policies.Advanced
• Automated Frequency Coordination (AFC)A cloud database system that authorizes 6 GHz standard-power operation while protecting incumbent links.Intermediate
• Band SteeringEncouraging dual-band clients to connect on 5 GHz or 6 GHz instead of 2.4 GHz.Intermediate
• Basic RateA data rate that all clients must support to join a BSS; management frames use the lowest one.Intermediate
• BonjourApple's zero-configuration service discovery using mDNS and DNS-SD on UDP 5353.Intermediate
• BSS ColoringAn 802.11ax identifier (1-63) in the PHY header that distinguishes overlapping BSSs on the same channel.Intermediate
• BSS Transition Management (BTM)An 802.11v exchange in which the AP suggests that a client roam to listed candidate APs.Intermediate
• Capacity PlanningForecasting the compute, storage, and network resources a service needs to meet demand and SLOs.Intermediate
• Central SwitchingForwarding client data through a CAPWAP tunnel to the controller, which bridges it to the wired network.Intermediate
• Central Web Authentication (CWA)A guest flow where the RADIUS server redirects clients to its own portal and then uses CoA to grant access.Advanced
• Change of Authorization (CoA)RADIUS extension (RFC 5176) allowing the server to change or terminate an active session.Advanced
• Channel BondingCombining adjacent 20 MHz channels into 40, 80, 160, or 320 MHz channels for higher data rates.Intermediate
• Channel Reuse PlanAn assignment of channels to APs so neighbors use different channels and same-channel APs are separated.Intermediate
• Channel UtilizationThe percentage of time a channel is busy, measured by an AP's radio.Intermediate
• Channel WidthThe amount of spectrum a Wi-Fi channel occupies: 20, 40, 80, 160, or 320 MHz.Foundational
• Cisco Catalyst 9800 Series Wireless Controller (C9800)Cisco's IOS XE-based wireless controller family, available as appliances, VM (9800-CL), and embedded options.Intermediate
• Cisco Catalyst CenterCisco's enterprise network controller and assurance platform, formerly Cisco DNA Center, with northbound Intent REST APIs.Intermediate
• Cisco CleanAirCisco AP hardware-based spectrum analysis that identifies and classifies RF interference sources.Intermediate
• Cisco SpacesCisco's cloud indoor location and IoT services platform, formerly Cisco DNA Spaces.Advanced
• Client SteeringInfrastructure techniques that encourage clients to roam to a better AP or band.Intermediate
• Co-Channel Interference (CCI)Performance loss when nearby BSSs on the same channel must defer to each other's transmissions.Intermediate
• Control and Provisioning of Wireless Access Points (CAPWAP)IETF tunneling protocol (RFC 5415) between lightweight APs and controllers, using UDP 5246 and 5247.Foundational
• Controller DiscoveryThe process by which a lightweight AP locates and joins a WLC.Intermediate
• Coverage Hole Detection (CHD)Cisco RRM feature that raises AP power when clients report poor signal.Advanced
• Decibel Relative to Isotropic Radiator (dBi)Antenna gain in decibels compared with a theoretical isotropic radiator.Foundational
• Delivery Traffic Indication Message (DTIM)A special TIM indicating that buffered broadcast and multicast frames will be sent after the beacon.Advanced
• DHCP Option 43A vendor-specific DHCP option used to give APs the IP address of their wireless controller.Intermediate
• Differentiated Services Code Point MappingTranslating Layer 3 DSCP markings to 802.11 user priorities and back, for end-to-end wireless QoS.Advanced
• Dynamic Bandwidth Selection (DBS)Cisco RRM feature that automatically selects channel width per AP.Advanced
• Dynamic Channel Assignment (DCA)Cisco RRM algorithm that automatically assigns AP channels to minimize interference.Advanced
• Dynamic Frequency Selection (DFS)A requirement that 5 GHz devices detect radar and vacate the channel when radar is present.Intermediate
• Dynamic VLAN AssignmentAssigning a client VLAN based on RADIUS attributes returned after authentication.Intermediate
• Effective Isotropic Radiated Power (EIRP)The highest signal strength radiated from an antenna: transmitter power minus cable loss plus antenna gain.Foundational
• Embedded Wireless Controller (EWC)Catalyst 9800 controller software running on a Catalyst access point or switch for small deployments.Advanced
• Enhanced Distributed Channel Access (EDCA)The 802.11e contention-based QoS access method using four access categories with different timers.Advanced
• Fast BSS Transition (FT)802.11r method that pre-derives keys from a key hierarchy so clients can roam without a full 802.1X or 4-way exchange.Intermediate
• Fine Timing Measurement (FTM)An 802.11 round-trip-time ranging method that measures distance between a station and AP using timestamps.Advanced
• FlexConnectCisco AP mode for branch sites that can switch client traffic locally and survive WAN outages.Intermediate
• Flexible Radio Assignment (FRA)Cisco RRM feature that converts redundant 2.4 GHz radios on flexible APs into 5 GHz or monitor radios.Advanced
• Guard Interval (GI)A period between OFDM symbols that absorbs multipath echoes to prevent inter-symbol interference.Intermediate
• Guest Anchor ControllerA controller, typically in a DMZ, to which guest traffic is tunneled from foreign controllers.Advanced
• Guest NetworkA WLAN that provides visitors with internet-only access isolated from internal resources.Foundational
• High Availability Stateful Switchover (HA SSO)Controller redundancy where a standby WLC maintains AP and client state for subsecond failover.Advanced
• Identity Pre-Shared Key (iPSK)A WLAN design in which each user or device group has its own passphrase on the same SSID.Intermediate
• IEEE 802.11axAmendment (Wi-Fi 6/6E) focused on efficiency in dense environments with OFDMA, UL/DL MU-MIMO, 1024-QAM, and TWT.Foundational
• IEEE 802.11beAmendment marketed as Wi-Fi 7, adding 320 MHz channels, 4096-QAM, Multi-Link Operation, and Multi-RU.Foundational
• IEEE 802.11eAmendment adding quality of service to the 802.11 MAC, including EDCA and HCCA.Intermediate
• IEEE 802.11hAmendment adding DFS and TPC so 5 GHz Wi-Fi can coexist with radar and meet European rules.Intermediate
• IEEE 802.11kRadio resource measurement amendment that lets clients request neighbor reports to roam faster.Intermediate
• IEEE 802.11mcRevision work that introduced Fine Timing Measurement (FTM) for Wi-Fi round-trip-time location.Advanced
• IEEE 802.11rFast BSS Transition amendment that allows key negotiation during or before reassociation for fast roaming.Intermediate
• IEEE 802.11vWireless network management amendment including BSS Transition Management and other client steering features.Intermediate
• IEEE 802.11wAmendment that protects selected management frames such as deauthentication and disassociation.Intermediate
• Layer 3 RoamingA roam between APs in different IP subnets in which the client keeps its original IP address.Advanced
• Lightweight Access Point (LAP)An AP that handles real-time radio functions while a controller manages configuration and control.Foundational
• Local ModeDefault Cisco AP mode that serves clients and tunnels all client traffic to the WLC through CAPWAP.Intermediate
• Low Power Indoor (LPI)A 6 GHz device class limited to indoor use and lower power without requiring AFC.Intermediate
• Mesh Access Point (MAP)A mesh AP that connects to the network wirelessly through a root AP or other mesh APs.Advanced
• Mobility GroupA set of wireless controllers that share client context to support seamless roaming between them.Advanced
• Modulation and Coding Scheme (MCS)An index combining modulation type and coding rate that determines a PHY data rate.Intermediate
• Monitor ModeAn AP mode that does not serve clients but scans all channels for rogues, intrusion, RRM, and location.Intermediate
• Multi-Link Device (MLD)A Wi-Fi 7 device with multiple affiliated stations or APs presenting a single MAC SAP for MLO.Advanced
• Multi-Link Operation (MLO)Wi-Fi 7 feature allowing a device to use multiple bands or channels simultaneously as one logical link.Intermediate
• Multi-RUWi-Fi 7 capability to assign more than one resource unit to a single user.Advanced
• Multi-User MIMO (MU-MIMO)MIMO in which an AP sends different spatial streams to multiple clients simultaneously.Intermediate
• Multicast Domain Name System Gateway (mDNS Gateway)A controller function that forwards Bonjour/mDNS service advertisements between VLANs.Advanced
• Multicast-to-UnicastConverting multicast frames into unicast frames per client so they can use higher rates and ACKs.Advanced
• Multiple-Input Multiple-Output (MIMO)Use of multiple transmit and receive antennas and radio chains to improve throughput and reliability.Foundational
• Neighbor ReportAn 802.11k list of nearby APs (BSSIDs, channels, capabilities) sent to a client to speed roaming.Intermediate
• Noise FloorThe ambient level of background RF energy on a channel, measured in dBm.Foundational
• Non-Wi-Fi InterferenceRF energy from devices that do not use 802.11, such as microwave ovens, Bluetooth, and cordless phones.Intermediate
• Opportunistic Key Caching (OKC)A non-standard but widely supported fast roaming method where controllers share a client's PMK among APs.Intermediate
• Optimized RoamingCisco feature that disassociates clients whose RSSI or data rate falls below thresholds to force roaming.Advanced
• Orthogonal Frequency-Division Multiple Access (OFDMA)Multi-user OFDM that divides a channel into resource units so several stations transmit simultaneously.Intermediate
• Peer-to-Peer BlockingAn AP or controller setting that prevents wireless clients from communicating directly with each other.Intermediate
• Policy ProfileThe Catalyst 9800 object defining client policy such as VLAN, ACLs, QoS, AAA override, and switching mode.Intermediate
• Policy TagA Catalyst 9800 object that maps WLAN profiles to policy profiles and is assigned to APs.Advanced
• Preamble PuncturingTransmitting a wide channel while skipping (puncturing) a busy or unavailable 20 MHz subchannel.Advanced
• Preferred Scanning Channel (PSC)One of fifteen 6 GHz 20-MHz channels (every fourth channel) that clients scan to discover APs.Intermediate
• Protected Management Frames (PMF)IEEE 802.11w feature that authenticates and protects Wi-Fi management frames such as deauthentication.Advanced
• Protocol AnalyzerA tool that captures and decodes network traffic so it can be examined protocol by protocol.Foundational
• QoS ProfileCisco precious-metal QoS levels (Platinum, Gold, Silver, Bronze) that cap the maximum priority per WLAN.Advanced
• Radio Resource Management (RRM)Automated management of AP channels, transmit power, and coverage based on measured RF conditions.Intermediate
• Real-Time Location System (RTLS)A system that tracks the location of devices or tags in real time using Wi-Fi, BLE, UWB, or other signals.Intermediate
• ReassociationThe process by which a client moves its association from one AP to another within an ESS.Intermediate
• Received Signal Strength Indicator (RSSI)A measurement of received signal power, usually reported in dBm by Wi-Fi radios.Foundational
• Reduced Neighbor Report (RNR)An information element in 2.4/5 GHz beacons and probe responses advertising co-located 6 GHz BSSs.Advanced
• Regulatory DomainThe set of allowed frequencies, channels, and power limits for a country or region.Foundational
• Resource Unit (RU)A group of OFDMA subcarriers (tones) allocated to one user in an 802.11ax/be transmission.Intermediate
• Retry RateThe percentage of frames retransmitted because no acknowledgment was received.Intermediate
• RF TagA Catalyst 9800 object that assigns RF profiles for each band to APs.Advanced
• RoamingA client moving its association from one AP to another in the same ESS while keeping connectivity.Foundational
• Root Access Point (RAP)The mesh AP with a wired connection that serves as the gateway for wireless mesh APs.Advanced
• Signal-to-Noise Ratio (SNR)The difference in dB between received signal strength and the noise floor.Foundational
• Simultaneous Authentication of Equals (SAE)Password-authenticated key exchange (Dragonfly) used by WPA3-Personal.Intermediate
• Single-User MIMO (SU-MIMO)MIMO in which all spatial streams of a transmission go to one client.Intermediate
• Site SurveyAssessment of the RF environment to design, deploy, or validate a WLAN for coverage and capacity.Foundational
• Site TagA Catalyst 9800 object that assigns an AP join profile and, for remote sites, a flex profile.Advanced
• Sniffer ModeAn AP mode that captures frames on one channel and forwards them to a remote packet analyzer.Intermediate
• Spatial Reuse802.11ax mechanisms allowing transmission during weak overlapping-BSS frames to increase channel reuse.Advanced
• Spatial Stream (SS)An independent data stream transmitted simultaneously from separate antennas on the same channel.Intermediate
• Spectrum AnalyzerA tool that measures RF energy across frequencies to identify interference, regardless of protocol.Intermediate
• Split MAC ArchitectureDivision of 802.11 MAC functions between a lightweight AP (real-time) and a controller (non-real-time).Intermediate
• Standard Power (SP)A 6 GHz device class allowed higher power indoors or outdoors under AFC control.Advanced
• Sticky ClientA client that remains associated to a distant AP despite better APs being available.Intermediate
• Target Wake Time (TWT)An 802.11ax power-saving feature in which client and AP negotiate scheduled wake times.Intermediate
• Transmit Beamforming (TxBF)Adjusting phase across multiple antennas so signals combine constructively at a specific receiver.Intermediate
• Transmit Power Control (TPC)Adjusting transmit power to reduce interference, defined by 802.11h and used by RRM algorithms.Intermediate
• Trigger FrameAn 802.11ax control frame that solicits and schedules simultaneous uplink transmissions from multiple clients.Advanced
• Unlicensed National Information Infrastructure (U-NII)FCC-defined unlicensed sub-bands in 5 GHz (U-NII-1 to U-NII-4) and 6 GHz (U-NII-5 to U-NII-8).Intermediate
• User Priority (UP)The 802.1D-based 0-7 priority value carried in 802.11 QoS data frames.Advanced
• Wi-Fi 6EWi-Fi 6 (802.11ax) devices that can operate in the 6 GHz band.Foundational
• Wi-Fi 7Wi-Fi Alliance name for 802.11be devices, emphasizing multi-link, wider channels, and lower latency.Foundational
• Wi-Fi Multimedia (WMM)Wi-Fi Alliance certification of 802.11e EDCA QoS with four access categories.Intermediate
• Wi-Fi Protected Access 3 (WPA3)Current Wi-Fi security standard that uses SAE for personal networks and mandates protected management frames.Foundational
• Wireless Intrusion Prevention System (WIPS)A system that monitors RF for rogue devices and attacks and can take containment actions.Intermediate
• Wireless LAN Controller (WLC)A device or virtual appliance that centrally manages lightweight APs, RF, security, and client policy.Foundational
• Wireless Mesh Network (WMN)A WLAN in which APs use wireless backhaul links to reach a wired-connected root AP.Intermediate
• WLAN ProfileThe Catalyst 9800 object defining an SSID and its Layer 2 and Layer 3 security settings.Intermediate
• WPA3 Transition ModeA mixed mode where one SSID accepts both WPA2-PSK and WPA3-SAE clients, with PMF optional.Intermediate