Wireless Network Troubleshooting

Question 1

Reflection

Answer 1

Reflection
• Wireless signals can bounce off some surfaces
• Depends on the frequencies and the surfaces
Position antennas to avoid excessive reflection
• May not be a problem for MIMO in 802.11n and 802.11ac

Question 2

Refraction

Answer 2

Refraction
• Signal passes through an object and
exits at a different angle

Question 3

Absorption

Answer 3

Absorption
• Signal passes through an object and loses signal strength
• Especially through walls and windows
• Signal passes through an object and loses signal strength
• Especially through walls and windows
Put the antennas on the ceiling
• And avoid going through walls

Question 4

Latency and jitter

Answer 4

Capacity issues

• Many people using the same wireless frequencies

Question 5

Attenuation

Answer 5

Attenuation
• Wireless signals get weaker as you move farther from the
antenna
• Move closer to the antenna - May not be possible

Question 6

Interference

Answer 6

Interference
• Interference
• Something else is using our frequency
• Predictable
• Florescent lights, microwave ovens, 
cordless telephones, high-power sources
• Unpredictable - Multi-tenant building
• Measurements
•netstat –e
• Performance Monitor

Question 7

Incorrect antenna type

Answer 7

Incorrect antenna type
• The antenna must fit the room
• Or the distance between sender and receiver

Question 8

Incorrect antenna placement

Answer 8

Incorrect antenna placement
• Interference
• Overlapping channels
• Check access point locations and channel settings
• A challenge for 2.4 GHz
• Much easier for 5 GHz

Question 9

Overcapacity

Answer 9

Overcapacity 
• Device saturation
• Too many devices on one wireless network
Common in large meeting places
• Conferences
• Airports
• Hotels

Question 10

Frequency mismatch

Answer 10

Frequency mismatch
• Devices have to match the access point
• 2.4 GHz, 5 GHz
Confirm the correct SSID settings
• Should be listed in the current connection status