Blog

Get the Newest Blog Direct to your Inbox

* indicates required
  • CWNP

Beamforming Do-Over

Cisco has officially entered the Transmit Beamforming (TxBF) game.  Let's take a look at their thankfully-updated (inside joke for those of you who missed the first version) whitepaper.

http://www.cisco.com/en/US/prod/collateral/wireless/ps5678/ps10092/white_paper_c11-516389.html

Cisco's TxBF implementation, called ClientLink, is the closest that I've seen in the market thus far to standards-based TxBF, though it's not really all that close to the 802.11n draft implementation.  ClientLink doesn't use explicit or implicit feedback mechanisms (because those are 802.11n draft features), but instead uses the 802.11a/g client's uplink traffic as the feedback mechanism - even though their whitepaper explicitly states, "without requiring feedback."  Using uplink traffic as the feedback mechanism has the obvious problem of sub-optimal beamforming if there isn't a continuous stream of traffic between the AP and client, but there isn't any other way of doing it really.  One thing to point out here is that the smaller the beamformed area, the more continuous uplink feedback is needed.

 

Continue reading...

  • CWNP

Change Management in the Home

Just how complicated can a home network get anyway?  It seems that every time I turn around, mine gets more complicated...and expensive.  In the beginning (years and years ago), it was just 2 computers and an ISDN router.  Then ADSL - SWEET!  Then 3, then 4, and pretty soon, a whole house of computers.  I have two laptops for work stuff, and every member of my family (wife + three kids) has one - all wirelessly connected of course.  Then there's the lab engineers that practically live in my basement with their work PCs, the lab test PCs, the Network Attached Storage (NAS) servers (primary and backup) which holds all of our family files, PoE Ethernet switch (to power the 5 APs), core Gigabit Ethernet switch, two Ethernet-attached printers, Application server (FTP, backup application, etc.), and it just keeps going and going forever.  Holy cow batman. Continue reading...

  • CWNP

The Last Lecture is a Great Beginning in 2009

If you haven't heard of Dr. Randy Pausch, Professor of Computer Science at Carnegie Mellon, then here's your chance.  His life lessons and his outlook on life are remarkable and valuable.  Someone gave me his book (www.thelastlecture.com) for a Christmas present, and it's simply fantastic - recommended for everyone over age 0.  I identify with this guy in more ways than I can count.  I'm only sorry that I'll never get to meet him (he passed on July 25, 2008 of Pancreatic Cancer).  In his book, he even has the same #1 rule as me: no whining.  How could you not love a guy like that?  His stories about Coach Graham are priceless.  Fundamentals, hard work, head fakes, and experience.  That's gold, Jerry! Gold!

If you like to read, the book (which is based on his lecture) is very well written and gives more content than the lecture - though the lecture is superb.  If you'd rather watch the lecture itself, there's a link directly on his website (noted above).  This book and lecture were just too valuable not to share.  Here's Dr. Pausch's website, and the Diane Sawyer interview video (bottom/left) is great.  http://download.srv.cs.cmu.edu/~pausch/

Enjoy.

Continue reading...

  • CWNP

More Wi-Fi Gadgets Needed

Something I've noticed lately is a big lack of Wi-Fi gadgetry.  Most Wi-Fi gadget makers do pretty well.  Some Wi-Fi gadgets have turned into very successful solutions.  Take MetaGeek's Wi-Spy and ZyXEL's AG-225H (which now has clones like Linksys's WUSBF54G) as examples - both have been very successful.  A  security researcher over at AirDefense built a little Linux-based Wi-Fi hacking box about 18 months ago that's one of the coolest things I've seen so far.  Why isn't anyone building more of these things?  Has everyone run out of ideas?  I doubt it.

I've come up with a couple of different items that I think would be way cool.  I don't have the time to build such gadgets, but I'd sure buy one if they existed.  I'm writing about them here just to give you an idea of the types of gadgets I'm talking about. Continue reading...

  • CWNP

Collectonomous - A New Paradigm

First, there was Autonomous, then lightweight, and now...there's Collectonomous, from the word, "Collective."  Think, "The Borg" - a hive mind.  If you're not familiar with The Borg, change careers and then go here:

http://en.wikipedia.org/wiki/The_Borg  

The object of my focus is Aerohive's new HiveUI.  It's a GUI built into their 802.11n APs that is capable of managing up to 11 APs (including itself) with the limitation of a single hive (group of coordinating APs).  With a snazzy UI, snappy initial configuration, APs that coordinate data forwarding among themselves, and enough features to fit almost any SMB scenario, it's a paradigm shifter.  Given that there's no separate controller appliance/software or licensing beyond just buying the modestly-priced APs, getting buyer's remorse should prove difficult.  If you want to scale beyond 11 APs, buy Aerohive's HiveManager appliance, and voila - you've scaled.  To avoid confusion, HiveManager isn't a controller, but rather a WNMS.

Continue reading...

  • CWNP

Something +/- Whatever

Obviously the name gives you no context of the content, so I'll need to explain.  I was a calibrator in the Army - that's right, a bonafide 35H that knew the Mouse Song cold.  Don't worry, I won't sing it for you.  If you're thinking, 'what's a calibrator?' this blog post is for you.  A calibration specialist (the official title) is someone who verifies and documents the accuracy of test equipment.  Occassionally (more than most calibrators would like) equipment won't calibrate properly and has to be repaired.  There are multiple specialty areas within the calibration profession, such as 1) DC & Low Frequency, 2) Physical Dimensional, and 3) Radio Frequency.  I think you can guess what my specialty was.  It was forced upon me because our 'RF' guy was reassigned.  Holy crap, the books doubled as chairs in a pinch.  Scared me to death. Continue reading...

  • CWNP

WCET is for System Designers

CWNP has been asked by various people over the last couple of months how CWNP certifications compare to the IEEE's new WCET certification.  Having taken a good look at WCET when it emerged, I already knew that it was a completely different certification than those offered by CWNP.  Nevertheless, inquiring people means that someone has to clarify.  So here goes...

CWNP creates certifications around Job Task Analyses (JTAs).  We identify career positions within a range of organizations, qualify what tasks must be performed within those positions, and then build exam objectives around those tasks.  Thus far, CWNP's certifications focus on 4 main groups of professionals:

1. CWTS - Technical Sales, Help Desk, and Support Technicians (official announcement forthcoming)

2. CWNA - Enterprise WLAN Administrators

3. CWSP - Enterprise Wireless Security Professionals

4. CWNE - Enterprise Wireless Design, Implementation, and Troubleshooting

There is certainly more to come, but I won't spill the beans just yet.  Now I would like to compare WCET to CWNP's certifications a bit.

Continue reading...

  • CWNP

The Unsung Heroes - Technical Documentation Professionals

One of the things that holds Enterprise Wi-Fi companies back is a lack of documented deployment strategies - often called Design Guides or Best Practices documents.  Cisco no doubt knows this because their design guides are released almost as fast as their equipment, and they keep them up-to-date.  These are great documents if you can find the time to read and digest up to 360 pages of detailed technical material per document (Enterprise Mobility, VoWLAN, & Security).  Aruba kinda/sorta has some of these types of documents, and they go by names like, 'Campus Wireless Networks Validated Reference Design' and 'Site Survey and Planning Pre-Deployment Guide.'  All combined, Aruba's guides make up enough documentation to get most of the job done.  Motorola has recently released their version, finally, and it's a Cisco-like 320 pages.  Sweet.  That's very good news for Moto VARs.

 

Continue reading...

  • CWNP

WIPS-2-Go

I've been asked (gratis of course) to help catch an intermittent 'borrower' of Wi-Fi and Internet service without the help of the company whose Wi-Fi network and Internet connection is being used.  Yeah, intermittent.  Normally you would use a WIPS for such security monitoring, but the company who owns the network isn't to be involved in catching the bad guy.  OK, I'm up for a challenge, so sure, let's do this.  First, what better than a WIPS to catch the bad guy?  Nothing.  So, let's use WIPS...in a way that it's really not designed to be used of course.

 

Continue reading...

  • CWNP

Here We Go Again...

Last week, I received calls from former SEs, channel managers, and more (previously with several WLAN companies) asking for help landing their 'next gig'.  You guessed it - layoffs.  I thought I'd snoop around for a little extra info when I stumbled across some links on Google mentioning various companies in the WLAN market that have laid people off recently.  This can't be good.

 

Continue reading...

Page 31 of 39