Wi-Fi vs wired - am I missing something

[flhrci]

So, on a whim I decided to hook up my wireless-G USB adapter to my desktop which I normally run wired to the router via gigabit LAN connection.

Attached is the speed test result.



When I run the test with the adapter disconnected and hooked back up to Ethernet the result is nearly identical.

So, here is my question. Why is it encouraged to run with Ethernet over wireless for speed when the results seem identical? What am I missing here?

David

 

[Jim Logajan]

Long Term Packet loss is a much bigger reason that WiFi tends to be slower. With TCP connections, lost packets are repeatedly resent until confirmed delivered. With UDP connections, that's not necessarily true - it is more "fire and forget."

Little recognized fact about 802.11 (WiFi), wired Ethernet, 3G, and 4G link layers is that they all support retransmissions up to a certain amount before giving up if their transmissions aren't acknowledged. As a result packet loss (as seen by higher layers) at the link layer rarely appears greater than 1% over any hop, but the penalty can be significant jitter and latency. This tends to mess with TCP's congestion avoidance and throttling algorithms which use round trip time (RTT) on the ACKs to adjust their transmission windows, which means that excessive jitter will reduce TCP throughput.