We had a user complain that the network "snappiness" is not the same on wireless (802.11g) as it is on his gig wired connection. Yeah, I know. In any case, he determined this by running the below Berkely Netanalyzr tool while connected to wireless. This seems to be telling him that although his connection speed is pretty good, his uplink/downlink is buffering and could have dropped packet issues (see below). We get basically the same report when we checked this, however we were able to download a debian ISO while streaming some music with no problem. I think the buffering message may be normal, and likely would get worse as the AP gets busy. I'll do further testing myself, but I'm interested if anyone else has used this tool, and is this even a valid tool for measuring wireless performance ? Of note, I haven't seen the buffer issue when testing on 802.11n, but I need to get more test points there as well.
The tool gives a lot of useful information, very cool. Unfortunately, it runs as a java applet, so no iPads or Galaxy support. http://netalyzr.icsi.berkeley.edu/ ---- output ----------------- Network bandwidth measurements (?<http://n3.netalyzr.icsi.berkeley.edu/info_bandwidth.html>): Upload 16 Mbit/sec, Download 17 Mbit/sec Your Uplink: We measured your uplink's sending bandwidth at 16 Mbit/sec. This level of bandwidth works well for many users. During this test, the applet observed 47 reordered packets. Your Downlink: We measured your downlink's receiving bandwidth at 17 Mbit/sec. This level of bandwidth works well for many users. During this test, the applet observed 13 reordered packets. Network buffer measurements (?<http://n3.netalyzr.icsi.berkeley.edu/info_buffer.html>): Uplink 1400 ms, Downlink 1000 ms We estimate your uplink as having 1400 msec of buffering. This is quite high, and you may experience substantial disruption to your network performance when performing interactive tasks such as web-surfing while simultaneously conducting large uploads. With such a buffer, real-time applications such as games or audio chat can work quite poorly when conducting large uploads at the same time. We estimate your downlink as having 1000 msec of buffering. This is quite high, and you may experience substantial disruption to your network performance when performing interactive tasks such as web-surfing while simultaneously conducting large downloads. With such a buffer, real-time applications such as games or audio chat can work quite poorly when conducting large downloads at the same time. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
