Cisco Certification: The Joy Of Hex

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Telepresence and Holography / Holograms - November 2008

Editor’s viewpoint on their differences, likenesses and future...

We all just recently viewed an historic CNN holographic interview on an historic Election Night. CNN stated this type of imaging has never been done before on National TV and I believe that. I haven’t seen anything like it. The live interview caught me by surprise and sure had the “wow” factor attached to it didn’t it? Here’s a link to the actual interview.

CNN Hologram Video

The question now has to be asked. Is it Telepresence?

I’m no expert on the subject but I’m going to throw my hat into the ring, go out on a limb and say yes, I believe it is. Although I know many video conferencing purists are rolling their eyes and grabbing their guns right about now with my statement.

While I do know that Telepresence still hasn’t been universally defined (Houston, we have a problem), here’s how I see it…. Broken down to its simplest form - “tele” (through electronic means) and “presence” (present). This is how I’m justifying my opinion by lumping holography and Telepresence together. Just as Telepresence is surely an offshoot of video conferencing, holographic imaging (like we viewed on CNN) surely has to be considered an offshoot of Telepresence. The interviewer was “telepresent” from Chicago and beamed into the CNN Election Headquarters. She was most assuredly - “telepresent”. There was negligible latency, the imaging was fantastic and both interviewers were rehearsed on what they would say. I’ve just recently read that CNN actually “downgraded” the experience to make it “movie” quality and not as good as it could have been. Maybe they thought us mere mortals would be shocked if they showed their complete hand. I have a feeling it was so big to them, they didn’t want it to get upstaged by the historic election. I’m willing to bet we’ll see the “true” power of this technology in the upcoming weeks and months when they can put the pedal to the medal and show it off without having it sidetracked.

What an amazing time for this technology (all differences and opinions aside). Telepresence Doctors, nurses, teachers, schools and healthcare (healthpresence) will benefit from the recent gains in this state-of-the-art industry whether holograms, Telepresence or holography. Airlines also have to see the threat to a portion of their business travel. Hell, who wants go through security and fly to Miami for a two-hour conference when you can look them in the eye via Telepresence?

Beam me up Scotty! Simply amazing…!

Visit the free Telepresence Forum for more information and discussion

Your Editor and Administrator - L II
"Ride on the Next Plane of Existence" TM

Cisco certification candidates, particularly CCNA candidates, must master binary math. This includes basic conversions, such as binary-to-decimal and decimal-to-binary, as well as more advanced scenarios involving subnetting and VLSM.

There's another conversion that might rear its ugly head on your Cisco exam, though, and that involves hexadecimal numbering.

Newcomers to hexadecimal numbering are often confused as to how a letter of the alphabet can possibly represent a number. Worse, they may be intimidated – after all, there must be some incredibly complicated formula involved with representing the decimal 11 with the letter "b", right?

Wrong.

The numbering system we use every day, decimal, concerns itself with units of ten. Although we rarely stop to think of it this way, if you read a decimal number from right to left, the number indicates how many units of one, ten, and one hundred we have. That is, the number "15" is five units of one and one unit of ten. The number "289" is nine units of one, eight units of ten, and two units of one hundred. Simple enough!

Hex numbers are read much the same way, except the units here are units of 16. The number "15" in hex is read as having five units of one and one unit of sixteen. The number "289" in hex is nine units of one, eight units of sixteen, and two units of 256 (16 x 16).

Since hex uses units of sixteen, how can we possibly represent a value of 10, 11, 12, 13, 14, or 15? We do so with letters. The decimal "10" is represented in hex with the letter "a"; the decimal 11 with "b"; the decimal "12" with "c", "13" with "d", "14" with "e", and finally, "15" with "f". (CCNA candidates will remember that a MAC address of "ffff.ffff.ffff" is a Layer 2 broadcast.)

Practice Your Conversions For Exam Success

Now that you know where the letters fall into place in the hexadecimal numbering world, you'll have little trouble converting hex to decimal and decimal to hex – if you practice.

How would you convert the decimal 27 to hex? You can see that there is one unit of 16 in this decimal; that leaves 11 units of one. This is represented in hex with "1b" – one unit of sixteen, 11 units of one.

Converting the decimal 322 to hex is no problem. There is one unit of 256; that leaves 66. There are four units of 16 in 66; that leaves 2, or two units of one. The hex equivalent of the decimal 322 is the hex figure 142 – one unit of 256, four units of 32, and 2 units of 2.

Hex-to-decimal conversions are even simpler. Given the hex number 144, what is the decimal equivalent? We have one unit of 256, four units of 16, and four units of 4. This gives us the decimal figure 324.

What about the hex figure c2? We now know that the letter "c" represents the decimal number "12". This means we have 12 units of 16, and two units of 2. This gives us the decimal figure 194.

Tips For Exam Day

Practice your binary and hexadecimal conversions over and over again before you take your CCNA exams. Binary math questions come in many different forms; make sure you have practiced all of them before exam day. The number one reason CCNA candidates fail their exam is that they're not prepared for the different types of binary math questions they're going to be asked, and that they aren't ready for hexadecimal questions at all.

You don't have time to learn how to do in on exam day. You've got to be ready before you go into the exam room, and the only way to be ready is a lot of practice.

Finally, make sure you read the question carefully. You've got hex, decimal, and binary numbers to concern yourself with on your CCNA exams. Make sure you give Cisco the answer in the format they're looking for.

Chris Bryant, CCIE (TM) #12933, has been active in the Cisco certification community for years. He has written several books that have helped CCNA candidates around the world achieve the coveted CCNA certification, including several concentrating on binary math conversions and subnetting questions that the average CCNA candidate will need to answer on their CCNA exams. He is the owner of The Bryant Advantage (http://www.thebryantadvantage.com ) where he teaches affordable world-class CCNA courses via the Internet. He's proud to have helped CCNA candidates around the world achieve their career goals. Mr. Bryant's books and courses are sold on his site, on eBay, and on several other major Cisco certification sites.

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To learn more about Telepresence, the revolutionary new style of immersive video conferencing; visit these websites:

Telepresence - "Ride on the Next Plane of Existence" - Telepresence
Telepresence Web Portal - Telepresence Internet web portal
Telepresence Report - 24/7 breaking Telepresence related news and information
Via Telepresence - Video conferencing via Telepresence
Telepresence Forum - Free user discussion forum for everything Telepresence related
Telepresence Today - Telepresence information and editor qualified headline news
Telepresence Resource Directory - Telepresence web resource directory
Telepresence Tube - Telepresence videos, pictures and more