Wireless Access

Hello,

 

I'm troubleshooting wireless issues related to choppy connections and latency.  I performed a packet capture for ~20 minutes while also in a web conference.  Afterward I reviewed the capture and found about 6% of the traffic to be netbios broadcasts.  Some clients send 8 broadcasts in less than a second for the same netbios name.

 

My question is a rather newbish one -- would this amount of broadcast traffic impact user experience while on wifi? All clients see these broadcasts, have to inspect/drop them, and the AP's also have to forward them outbound instead of processing others packets.

 

Retransmissions and duplicate acks are present as well, but they amount to less than 1.4% the total traffic captured.

In a word, yes it will affect it. Broadcasts are typically sent at the lowest wireless rate, which means it consumes more airtime than regular data.

Thank you for the quick response!

Is there anything else that could be causing a slowdown, or a way to troubleshoot the duplicate ack's, retransmissions, etc? From what I've read those are typical with congestion and as long as they do not reach more than 2% of the total traffic they can be ignored.

You should turn on broadcast filtering to eliminate that, so you can see if you have other issues.

Also, besides filtering broadcast and multicast traffic on the wireless wherever possible, separate wireless and wired clients in separate VLANs to limit broadcasts that may come from the wired network to propagate to the WLAN.