Wireless Troubleshooting for the Technically-Inclined

DRAFT - Feedback Welcomed!

Good Wireless Connections

A good wireless connection should:

- Be authenticated with a username.
- Have an SPS IPv4 address beginning with 157.246.
- Have an RSSI (Received Signal Strength) value of -65 or less (Fix: Move closer to a WAP, or move away from large metal objects, such as filing cabinets). Wireless clients will start experiencing noticeable reception issues when the signal weakens to roughly -72 dBm or more.
- Have a good signal-to-noise ratio (Noise dBm - RSSI dBm should be greater than 25 dB). (Fix: Have Jacob investigate. Be sure to include the date and time, room and location, BSSID, RSSI, Noise values, and the device barcode)
- With the advent of more low-power mobile devices, we are seeing situations where RSSI from the WAP is good, but a battery-powered mobile device is unable to transmit a strong enough signal. We can look into this via Cisco Prime. (Fix: move closer to a WAP) *Add more info here*

On the Mac, you can hold down the Option key while left-clicking on the Airport menu item. You should see something like the following:

This screenshot shows an exceptionally good wireless situation. This is from a MacBook Pro right under a Wireless Access Point. RSSI is -41. The SNR (Noise-RSSI) is over 50 dB

RSSI

In telecommunications, received signal strength indicator (RSSI) is a measurement of the power present in a received radio signal. When an RSSI value is represented in a negative form (e.g. −100), the closer the value is to 0, the stronger the received signal is.

Troubleshooting Steps

Does the client see the SSID it wants to connect to?

What Jake Needs To Look Into Wireless Issues

In order to make things efficient and preserve sanity, I need the following information: