Wireless Networking Fundamentals Flashcards
WPAN
Wireless Personal Area Network:
Devices are within 10 meters of each other
Example: Bluetooth
WLAN
Wireless Local Area Network:
Provides access to a campus (typically wired) network, without the need for a cable
Devices within 100m of WAP
WMAN
Wireless Metropolitan Area Network:
Covers a large area (example: city)
Ad Hoc Networks
Peer-to-peer
2+ wireless stations communicate directly
IBSS (Independent Basic Service Set)
Infrastructure Mode
Stations communicate via AP
Multiple APs can be deployed
Wifi Direct
Allows devices to be connected to an AP & also be part of peer-to-peer wireless network
Does not operate in Ad Hoc
– It’s an extension to infrastructure mode
WPS (Wifi Protected Setup) enables connection setup by pushing a button
WPAN
Predefined Services
—Miracast to wireless external monitor
—DLNA (Digital Living Network Alliance) allows devices to stream music/video
—Direct Print
Wireless Bridges
Can be used to connect areas not reachable via cable to the network
Mesh Networks
One AP radio is used to serve clients
The other radio connects to the backhaul network
WAPs
Wireless Access Points:
Provide connectivity between wireless stations & between wired/wireless networks
Wireless is Half-duplex
—Only one device can communicate at a time
BSS
Basic Service Set:
An AP centralizes access & control over a group of wireless devices
The devices & their wireless settings make up a BSS
DS
Distribution System:
Connects WAPs to the wired network
BSSID
Basic Service Set Identifier:
Devices within BSSs are identified by BSSID which is based on their MAC
BSA
Basic Service Area:
AKA: Wireless Cell
The wireless coverage area of an AP
SSID
Service Set Identifier:
Unique wireless network name
Multiple SSID:
–A single AP can support multiple SSIDs
—-Ex: “Corporate” & “Guest”
–Different SSIDs can have different security settings & mapped to different VLANs
Beacons
WAPs broadcast info about their WLANs with beacon frames
Can be disabled
ESS
Extended Service Set:
The same SSID can be supported across multiple APs to give a larger coverage area
Roaming
Wireless client stations can roam across APs supporting the same WLANs
WLC
Wireless LAN Controller:
In a large campus, configuring a large amount of APs one by one becomes unmanageable
Can be physical or virtual
The WLC also monitors the wireless quality & controls the channels & power of the APs
—It can also detect rogue APs
Autonomous AP
Standalone APs
Lightweight AP
APs with a WLC
The LAP (Lightweight AP) downloads its configuration from the WLC
—This includes what WLANs it should support & their settings
Zero Touch Provisioning
Gives the ability to install a network appliance somewhere without requiring local configuration
Lightweight APs support this
They discover their WLC via:
—DHCP - option 43 gives the IP of the WLC
—DNS - “cisco-capwap-controller” resolves the IP of the WLC
—Local subnet broadcast
CAPWAP
(and port numbers)
Control and Provisioning of Wireless Access Points:
Open standard that enables WLCs to manage a collection of WAPs
Communications are encrypted inside a DTLS CAPWAP tunnel
Uses UDP ports 5246 & 5247
Split MAC
Work is moved from the APs to the WLC which is why they are called LAPs
Real-Time traffic is still handled by the AP in order to provide suitable performance
—The rest is handled by the WLC
AP vs. WLC Operations
AP Operations:
—Client handshake when connecting
—Beacons
—Performance monitoring
—Encryption/decryption
—Clients in power save
WLC Operations:
—Authentication
—Roaming control
—802.11 to 802.3 communication
—Radio frequency management
—Security management
—QoS management
