Troubleshooting Wireless networks

CompTIA+ Network Learning

Bandwidth

Bandwidth

The theoretical speed of data going across a network.

Throughput

The actual speed of data on a network.

802.11a

A wireless network with a maximum bandwidth of 54 Mbps and a common throughput of 20 to 30 Mbps.

802.11b

A wireless network with a maximum bandwidth of 11 Mbps and a common throughput of 5 to 7 Mbps.

802.11g

A wireless network with a maximum bandwidth of 54 Mbps and a common throughput of 30 to 32 Mbps.

802.11n

A wireless network with a maximum bandwidth of 600 Mbps and a common throughput of 140 to 150 Mbps.

802.11ac

A wireless network with a maximum bandwidth of 1300 Mbps or 1.3 Gbps and a common throughput of 100 to 500 Mbps.

802.11ax

A wireless network with a maximum bandwidth of 10 Gbps and a common throughput of 600 to 900 Mbps.

Distance

The range of coverage for different wireless networks.

RSSI

Received Signal Strength Indication, an estimate and measure of the power level that a client device is receiving from a wireless access point or router.

EIRP

Effective Isotropic Radiated Power, the maximum amount of power that could be rated from an ideal isotropic antenna.

Antennas

Devices used for transmitting and receiving radio frequency waves in wireless networks.

Omnidirectional Antenna

An antenna that radiates radio frequency waves in all directions.

Dipole Antenna

An antenna that produces radio frequency waves in two directions.

Yagi Antenna

A unidirectional antenna that sends radio frequency waves in one direction.

Parabolic Grid Antenna

A unidirectional antenna commonly used for site-to-site applications over longer distances.

Unidirectional antenna

An antenna that radiates or receives signals in a specific direction.

Line of sight

A clear and unobstructed path between two antennas for optimal wireless communication.

Deteriorating signal

A weakening or loss of wireless connection due to obstacles such as trees, snow, or heavy rain.

Omni-directional antenna

An antenna that radiates or receives signals in all directions.

Polarization

The orientation of the electric field in radio frequency waves emitted by an antenna.

Channel utilization

The measure of airtime utilization for a particular frequency or channel.

Site survey

The process of planning and designing a wireless network to determine optimal access point locations, power levels, and channel usage.

Association time

The time it takes for a wireless client to connect and authenticate with an access point before being able to use the network.

Association Process

The process of establishing a connection between a client device and a wireless network.

Signal Strength

The measure of the power and quality of the wireless signal received by a client device.

Coverage

The extent of the area where there is sufficient signal strength for a wireless device to function properly.

Wireless Site Survey

A process of conducting a survey to determine the coverage area of a wireless network and identify areas with the highest signal strength.

RSSI

Received Signal Strength Indicator, a measurement of the strength of the wireless signal received by a client device, measured in decibels.

EIRP

Effective Isotropic Radiated Power, a measurement of the power level of a wireless signal transmitted by an access point, measured in decibels.

Signal Booster

A device used to amplify and increase the strength of a wireless signal.

Antenna

A device used to transmit and receive wireless signals, with a higher dBI rating indicating a stronger signal.

Wireless Repeater

A device that receives a wireless signal and retransmits it at full strength, extending the coverage area of a wireless network.

Extended Service Set (ESS)

A configuration where multiple wireless access points are connected to provide coverage over a larger area.

Interference

The disruption of wireless signals caused by multiple networks communicating on the same channel or frequency.

Attenuation

The reduction in signal strength between the transmission and receipt of a wireless signal, caused by distance, physical obstacles, or interference.

Multipath Reception

The phenomenon where wireless signals bounce off walls and objects, leading to slower and weaker signals at the receiver.

Disassociation

The process of a client device being disconnected from a wireless access point, which can occur due to idle timeout, session timeout, network changes, or other factors.

Wireless network changes

Changes made to a wireless local area network that cause the network to be disabled and then reenabled.

Shared pass phrase

The password used to secure a wireless network that, when changed, requires devices to reconnect and reauthenticate.

Manual deletion

When a wireless client is removed by an administrator, causing the client to be disassociated and needing to reconnect.

Authentication timeouts

When the authentication or key exchange process fails to finish within a given time, resulting in the wireless client being disassociated and needing to restart the authentication process.

Access point radio reset

When the access point radio is reset, causing all clients to be disassociated and the radio to be turned off and on, requiring clients to begin the association process again.

Deauthentication attack

A wireless attack used by hackers to disassociate wireless clients and attempt to capture packets used in the association and authentication processes in order to crack the shared pass phrase and gain access to the network indefinitely.

Incorrect SSID

When the wrong Service Set Identifier (SSID), which is the name used to identify a wireless network, is used, causing connection issues.

Incorrect passphrase

When the wrong pre-shared key or passphrase is used to authenticate to a wireless network, resulting in disassociation from the access point and the need to reconnect.

Encryption protocol mismatch

When the encryption protocol used by a wireless network does not match the one being used by the client, causing connection issues.

Captive portal

A webpage displayed to newly connected users of a wireless network before they are granted broader access to network resources, often requiring authentication, payment, or acceptance of terms and conditions.

Captive portal

A web page that is displayed when connecting to a wireless network, requiring the user to log in or agree to terms and conditions before accessing the internet.

HTTP redirect

A method used by captive portals to redirect web traffic to the captive portal login page.

DNS redirect

A method used by captive portals to redirect DNS requests to the captive portal login page.

Default gateway

The IP address of the router that connects a device to a network, used for routing traffic between different networks.

IP configuration

The network settings of a device, including its IP address, subnet mask, default gateway, and DNS server information.

Troubleshooting

The process of identifying and resolving problems or issues with a system or device.

DNS server

A server that translates domain names into IP addresses, allowing devices to access websites and services on the internet.

DHCP

Dynamic Host Configuration Protocol, a network protocol that automatically assigns IP addresses and other network configuration settings to devices.