In the Wireless LAN (WLAN) world, we have started to worship in front of the False God of dB.
Books, white papers, study guides, and design manuals have touted the value of the RSSI (dB) so much we have used this as a sole way of designing and evaluating our Wi-Fi Networks. dB is a false god and we need to mature and move past having ‘Signal’ be our main goal in WLAN designs!Continue reading...
I was going to write long, thoughtful emails to all of my Strategic Marketing VP friends and Sr. TME friends individually, but I just don't have the time. So, this is the next best thing - albeit a bit impersonal. If you work at a Wi-Fi manufacturer and hold either of these positions, or perahps another similar position where you find yourself speaking with industry analysts and media professionals, please lend an ear. It'll pay liberal dividends.
I'm not trying to ruffle feathers. I just want to be helpful to both sides of this equation. This is just a polite observation. Do with it as you will.
Based on an Apple iPod Touch!
OK, before you ‘freak’ and think that I’ve lost my mind… just hold on a minute and read the rest of the article. This is the smallest, lightest, and ‘funnest’ WLAN test kit out there.
For doing a lot of smaller, quicker WLAN troubleshooting, this is a suitable solution. In addition, you get all the benefits of having an Apple iPod – with music, podcasts, videos, and games available as well as the Network Troubleshooting Tools!
Since I went ahead and threw down the gauntlet in my last post, I thought you should taste-test a couple of Kool-Aid 'samples' while I had everything out on the table.
'Kool-Aid' is about a company's overall approach (philosophy) to networking (in this case, Wi-Fi networking). At first sip, you might think the two flavors we’ll be discussing taste similar, but one of them has a bit of a 'twang.' It's like sweet tea that's been sitting out a little too long, and if you're an avid sweet tea drinker like me, that twang isn't a good thang. Motorola, Aruba, and Meru, (the 2nd, 3rd, and 4th place Wi-Fi vendors in the market) ALL serve up an 'All Wireless Enterprise' flavor. In contrast, Cisco serves up the 'Wireless-is-an-Extension-of-the-Wired-network' variety.
ALL WIRELESS ENTERPRISE (AWE) means the distribution and access layers of the traditional 'Core, Distribution, Access' network design layers are primarily, if not entirely, wireless. Wi-Fi would, in today's market, be the primary technology for access. But Wi-Fi, WiMAX, and other technologies could serve in a distribution layer capacity. It's a given that the core of any sizable network will remain wired for capacity and dependability. Vendors who are serving AWE flavor know this, and have typically partnered with wired infrastructure vendors (if they can't offer wired infrastructure equipment themselves) to provide this part of the networking meal plan. More or less, AWE vendors believe that wireless brings a significant value to the enterprise when implemented properly, and they want to specialize in that area alone.
WIRELESS as an EXTENSION of the WIRED network (WEW) gives you a mixture that allows wireless to add value to the wired network, but the wired network remains 'primary' - even out to the network's edge (access layer). WEW flavor has the underlying requirement of the vendor or the vendor's partner(s) being able to (and wanting to) sell primarily wired networking equipment. Wireless networking equipment is then sold only where specifically needed (when wired network equipment can't do the job) for the purpose of maximizing gross income.Continue reading...
I'm often asked by individuals wanting to get into the IT networking industry where they should start. My answer, like everyone else's, has always been:
1. Cisco CCNA - if you're going to work in a Cisco-centric environment
2. CompTIA Network+ - if you're not
Because of the flexibility and reporting capabilities built into most site survey applications, individuals can either knowingly, or accidentally, use these features to ‘Cheat’ and make survey data look different than it really is.
OK, I understand the word ‘Cheat’ is a pejorative, and connotes some sort of blatant attempt to break some rules or misrepresent. Many individuals just didn’t know any better when they applied these methods in their survey reporting. I’m not implying that these techniques suggest any malfeasance, only ignorance.
As a customer, the best protection against this type of deception is to request not only the paper or PDF report, but the actual data files so you can review and analyze the data directly yourself.
Below are some of the techniques that allow one to modify and present survey data to reflect whatever you might desire.
Be wary of using any of these techniques on your own analysis or in reviewing data presented by other third parties. Continue reading...
Seven Rules for Accurate Site Surveys
The process of gathering appropriate and accurate data during a Site Survey is as simple as following a few easy rules.Continue reading...
Break the rules, however, and you could end up with totally useless – but colorful – Heat Maps that have no value to your organization.
These rules have been gleaned through hundreds of site surveys and through teaching over hundreds networking professionals how to use Site Survey products.
I spoke to someone today who, like me, is on a quest to define everything that is Wi-Fi. She (my good friend Joanie Wexler) is on a quest to make sense of the ever-changing vendor definitions for their technology and to relate it back to a standard definition. KUDOS Joanie! Our mission here at CWNP is to help the industry learn to USE the standards-based terminology created by the IEEE and Wi-Fi Alliance. Where there is no standard terminology, we create it. Examples are 'Single Channel Architecture (SCA)' and 'Multiple Channel Architecture (MCA)'. You're welcome. ;-) My good friend Joel Barrett has picked up the CWNP torch of standardized exam terminology and has created an entire Wi-Fi dictionary. If you haven't seen it, see here:
If you want an example of why this stuff matters, here's my favorite. Meru and Extricom, the only two vendors to ever release products that use the Single Channel Architecture, call the blob that is their collective logic of controller and APs on a single channel, 1) channel spans, 2) channel stacks, 3) channel blankets, and 4) channel layers. Geez Luiz. Why? I'll tell you why: marketing terminology run amuck. :-) No offense is meant to either vendor of course. This is just my favorite example - there are many more just like it that involve other vendors. Continue reading...
Everyone seems to have jumped onto the Airtime Fairness bandwagon all of a sudden. An idea originally introduced by Meru, Airtime Fairness has various implementations these days. Airtime Fairness is a feature that is, by design, meant to allow faster clients to have more airtime than slower clients. Most Wi-Fi cells (basic service sets) have clients supporting one or more PHYs connected and certainly all of those clients roam closer and further from the AP almost continually. When you add in interference sources, multipath, and any number of RF issues, data rates go up and down like the wind changing direction. Airtime Fairness is one method of optimizing a cell's aggregate throughput, and certainly there are others (that we won't talk about in this blog post).