Author Archives: Matthew McClearn

How to troubleshoot RTP audio streams via packet capture

When a customer reports a poor wireless VoIP experience and you rule out the low-hanging fruit and best practices, e.g. roaming optimization, verification of clean RF environment, and other client configuration, where do you go next? Audio streams consist of a steady delivery of small frames (typically 200-250KB). The average delay between audio frames isContinue reading “How to troubleshoot RTP audio streams via packet capture”

How to take a full frame packet capture with Ekahau Analyzer app and sidekick 2

The Sidekick 2 is an incredible tool for the wireless network professional. One of its many features is the ability to take over-the-air packet captures on 4 simultaneous channels. If you’re like me, you look forward to decrypting those captures to see L3/L4 information and use it in Wireshark display filters. The Sidekick 1 andContinue reading “How to take a full frame packet capture with Ekahau Analyzer app and sidekick 2”

Wireless Voice Best Practices (in a pre-6GHz world)

For the almost 3 years now I’ve been working for Wireless VOIP client. In that time I have troubleshooted over 1300 support cases related to our clients’ networks and our devices’ interactions with it. Here is a culmination of what I’ve learned. QoS Beware of (Call) Admission Control Avoid 2.4GHz if possible. Ensure time spentContinue reading “Wireless Voice Best Practices (in a pre-6GHz world)”

Three methods of determining if QoS is enabled on a WLAN via packet capture

Method 1: Presence of tagged parameter containing WMM in beacon 2. Choose a frame that contains Beacon Frame in the “Info” column of the Packet List Pane. Alternatively, you can use Wireshark display filter wlan.fc.type_subtype == 8 3. Expand the IEEE 802.11 Wireless Management and Tagged parameters headers in the Packet Details Pane 4. If there is a “Tagged parameter” containing WMM, then this WLAN has QoS enabled 5. Conversely,Continue reading “Three methods of determining if QoS is enabled on a WLAN via packet capture”

802.11 Multicast Delivery

I went through 8 years of my career in networking without having to know a thing about multicast. I was first exposed when onboarding network requirements for IPTV on hospitality networks. Currently I support wireless clients that use multicast to send audio to multiple recipients. Oftentimes I am asking customers to take packet captures forContinue reading “802.11 Multicast Delivery”