Explaining Wireless Fundamentals Flashcards
What is a WPAN? What distance is typically covered?
Wireless Personal Area Network - typically < 5 - 10 meters.
Uses technology like Bluetooth to connect devices.
What is a WLAN, what is the IEEE standard and what is the typical distance covered?
Wireless Local Area Network
IEEE standard = 802.11
< 100 meters (328 feet)
What is a WMAN and what is the typical distance covered?
Wireless Metropolitan Area Network
Commonly provides point-to-point or point-to-multipoint backbone.
Cover distances greater than 100 meters (328 feet or more)
What is an Ad Hoc network?
Connection between two wireless devices.
Creates an Independent Basic Service Set (IBSS).
Contains a limited number of devices because of collision and organization issues.
Also called a peer-to-peer (wireless) network.
What is Wi-Fi Direct and what is the main difference compared to Ad Hoc?
It is an example of a WPAN where connectivity is directly between devices, but is an extension of the infrastructure mode of operation instead of IBSS mode like Ad Hoc networks.
An example of Wi-Fi Direct is Wi-Fi Protected Setup (WPS).
What are the predefined services that Wi-Fi direct brings?
Miracast connections - allow a device to display photos, files and videos on an external monitor or television.
Wi-Fi Direct for Digital Living Network Alliance (DLNA) - lets devices stream music and video between each other.
Wi-Fi Direct Print - ability to print directly from a smart phone, tablet or PC.
What are characteristics of an AP functioning in infrastructure mode?
- AP is a translation bridge between 802.3 (wired media) and 802.11 (wireless media).
- Wireless is a half-duplex environment.
- A basic service area (BSA) is also called a wireless cell.
- A basic service set (BSS) is the service that the AP provides.
What is an ESS?
Extended Service Set
When you put more than one AP in an area, where they work together with shared SSIDs, etc.
What does SSID & BSSID stand for?
Service Set Identifier
Human readable, not unique name of the network.
Basic Service Set Identifier
Unique name of the wireless network, often includes the MAC of the AP. We don’t see this, only the devices do in the
background.
What is the distribution system (or distribution network) within WLAN architectures?
The distribution system (or network) is essentially the wired network or devices that the APs forward their traffic to for distribution.
What are MBSSIDs?
Multiple Basic Service Set Identifiers
It’s like several virtual APs all on the one physical AP so that you can have multiple SSIDs sent out, yet still differentiate the traffic.
What is CAPWAP?
_C_ontrol _a_nd _P_rovisioning of _W_ireless _A_ccess _P_oints
- Uses the Split MAC model.
- Protocol to manage a collection of APs
- includes WLC discovery and join process, AP configuration and firmware push, statistics and security enforcement
- CAPWAP encrypted tunnel formed between WLC and AP
- APs join WLC, then download any new software and configuration changes
- Firewalls should allow UDP 5246 (Control Plane) & UDP 5247 (Data Plane)
What types of vlans are needed for WLANs?
- Management VLAN - for WLC management interface
- AP VLAN - can be the same or different than the management VLAN
- Data VLAN - need VLAN(s) for each SSID on the WLC
What is the switch port configuration for a Centralized AP vs. Standalone AP?
Centralized AP - The switchport is configured as an access port with the ‘AP VLAN’.
Standalone AP - The switchport is configured as a trunk port with allowed VLANs. You also need to configure a native vlan on
the trunk for the AP to properly be managed. [Example - Switch1 (config-if)#switchport trunk native vlan 12]
What is a WGB?
Workgroup Bridge
An AP that provides a wired device connected to it’s ethernet port a wireless connection back to the rest of the network. WGBs can also connect to switches to provide multiple wired devices with connectivity.
