Full Wi-Fi bars but my Youtube is buffering!!

My Youtube video was buffering although I had full bars on my iPhone’s Wi-Fi connection. Weird but I am sure I am not the only one who has faced this, here’ why..

We believe more the number of signal bars better the Wi-Fi speed, but that’s not how Wi-Fi really works..

Signal Strength indicates the strength of the signal between my Phone and the AP but that does not necessarily mean peak Wi-Fi performance. Actual Wi-Fi experience depends on more than just signal strength.

RSSI is measured in dBm (values closer to 0 imply better signal strength):

-30 to -50 dBm → Excellent (Fast and suitable for download)

-51 to -65 dBm → Good (Suitable for HD video streaming)

 -66 to -75 dBm → Fair (Web browsing)

 -76 to -90 dBm → Poor (Unstable, client should probably roam to neighboring AP)

What factors affect Wi-Fi performance while the signal strength is good?

  • Interference and Noise-
    • Rogue wireless devices operating in the same band.
    • Bluetooth, microwaves in 2.4 GHz band. 
  • Device Count-
    • too many devices associated on the same AP resulting in lower airtime for transmission (often observed in dense RF environments like airports)
  • Band-
    • 2.4 GHz is often more congested than 5/6 GHz, if the client happens to associate 2.4 GHz instead of 5/6 GHz the performance is likely to be poor.
  • Channel width-
    • 5/6 GHz radios support higher channel widths but if the radios are statically set to lower channel widths this could result in poor performance.

What factors on the wired network could result in poor performance?

  • Wired Backhaul capability–
    • A Wi-Fi 6 or Wi-Fi 7 AP is capable of high throughput but if the uplink switch port is 1 Gbps capable, poor performance is expected.
  • Firewall rules-
    • Network admins often throttle bandwidth per client or on Guest WLANs so that a single client or low priority BYOD clients do not occupy valuable bandwidth.
  • ISP issue-
    • Internet service itself is slow or affected.

Related Blogs-

Wireless Troubleshooting

How to Troubleshoot 6 GHz 320 MHz cw client association?

Minor Outage: Wireless client cannot connect to the internet!!

Comprehensive Reads-

Wireless not working!!!

RRM- Radio Resource Management

Quick Reads-

Common Reasons affecting wireless performance

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