Thanks for the clarification, Dave. I hadn't seen the followup to the original article. This is very helpful.
Tim Winders | Associate Dean of Information Technology | South Plains College From: Dave Molta [mailto:[EMAIL PROTECTED] Sent: Thursday, June 14, 2007 10:25 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Cisco vs. Meru article Just to elaborate a bit, the article James sent around was not the original Meru-Cisco feature story but rather a column that reports on results of subsequent testing. In this column, I reported three things. First, Cisco was unsuccessful in getting the Wi-Fi Alliance to rescind Meru's certification. Since WFA certifies interoperability rather than standards compliance, this is not proof that Meru isn't stretching standards a bit but it still casts a cloud over Cisco's allegations. Second, I reported findings from subsequent tests where we added Aruba to the mix and found that Cisco's performance also cratered when co-located with Aruba gear. Again, that could indicate that Aruba is also somehow playing foul as well (Cisco speculated that they might be using a variation of PCF interframe spacing, though Aruba denied it) but it doesn't look that way to me. Finally, we decided to re-run these interference tests with different mixes of clients, using Atheros, Broadcom, and Intel chipsets. We found significant differences in the performance results. Atheros-based clients performed best. The broader issues here relate to standards compliance (e.g., to what degree can a vendor selectively implement certain elements of a QoS standard?) and, perhaps more importantly, performance issues with Wi-Fi that may arise in the future as the density of deployed networks results in increasing levels of co-channel interference. I am particuarly concerned about the intersection between private enterprise WLANs and public metro Wi-Fi networks. It may not be a big problem today but I wonder if it will be a problem in the future. We understand that our tests represent worst-case scenarios that few enterprises currently experience but sometimes there is value in pointing out the worst-case situations. If there's a silver lining here, it may be that 11n is likely to push most enterprises towards more pervasive 5 GHz deployments, where co-channel interference is not such a big issue. dm ________________________________ From: Peter Morrissey [mailto:[EMAIL PROTECTED] Sent: Thursday, June 14, 2007 11:03 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Cisco vs. Meru article I'm with you Jamie. Standards are extremely important, but only to the extent that they serve the consumer. You still have to buy the whole system from one vendor, so what is the difference? As long as the clients will be interoperable, then I don't think it really matters. I could be missing something, but that is my take on the whole thing. Meru appears to offer some compelling QOS features. Pete Morrissey Syracuse University ________________________________ From: Jamie Savage [mailto:[EMAIL PROTECTED] Sent: Thursday, June 14, 2007 10:50 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: [WIRELESS-LAN] Cisco vs. Meru article Hi, The attached article was in the May 28th issue of Network Computing. Regarding Meru vs. Cisco and the possibility of interference with co-located APs. I'd be interested in any commentary. We're currently a Cisco shop (autonomous APs) and realize we're heading for a forklift wireless change in the near future (most of our fat APs can't be converted to thin). Even if Meru violates the 802.11 standard (as claimed by Cisco), as we control the airspace on campus, I guess we don't care if we cause interference issues with devices (ie..rogues) that shouldn't be there in the first place. ...........comments anyone?...........thx...............J James Savage York University Senior Communications Tech. 108 Steacie Building [EMAIL PROTECTED] 4700 Keele Street ph: 416-736-2100 ext. 22605 Toronto, Ontario fax: 416-736-5701 M3J 1P3, CANADA ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
