QueTwo's Blog

thouoghts on telecommunications, programming, education and technology

Monthly Archives: December 2007

Wireless IP Phones

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A few months ago, my boss came back excited about some news coming out of Ohio State University — they were going to be implementing WiFi IP Phones throughout their campus.  I’m sure you can guess what the next things were out of his mouth :  “Lets do that!”

WiFi phones, while sounding like a great idea on paper, their implementation is a lot more tricky than one would first imagine.  Everybody thinks that WiFi is one of those technologies that just ‘work’ — you just open your laptop and start your work.

Unfortunately, VoIP (Voice over IP), is extremely sensitive to any network activity or blips.  A typical conversation will begin to be broken up if there is a disruption on the network for longer than 50ms.   Often times when a VoIP system is deployed, the IT infrastructure needs to be conditioned for voice traffic.  You need to set priorities to the different types of traffic, regulate how much bandwidth each type of traffic can have, etc.  Over the past 7 years or so, this field has been growing and is finally becoming mature.  VoIP works fairly well, assuming you have done the above. 

When you throw VoIP onto a wireless network, you throw an entire additional host of problems into the mix. 802.11a, b, g and n networks behave very similar to token-ring based wired networks; only one device can talk at a time, and only when told it can talk.  In addition, the data rates that the devices communicate at change based on the quality of the signal to the access points.  Most of the technologies that exist today rely on the principal that says we can dedicate xxKb of bandwidth to application a, and let application x talk as much as it wants until it fills that pipe.  With no guaranteed bandwidth transmission rate, or no guaranteed talk path, voice becomes a “best effort” to most equipment, and usually suffers.  Add in a few WiFi VoIP devices and you have a true contention issue. 

Avaya / Spectralink designed a box that is supposed to “schedule” the WiFi devices so they do not attempt to talk at the same time.  That, combined with some of the new WiFi technologies from Meru and Aruba, will allow WiFi VoIP devices to work properly in theory.  Again, sounds good on paper, but we will see in short order.  At MSU, we recently setup a lab with two WiFi VoIP phones (models 3645), and the “AVPP” or Avaya Voice Priority Processor.  This setup is supposed to allow the phones to work within the range of the AP.  Seems to work, except, as expected, the voice is very choppy. Since we did not deploy the solution on one of the newer access points, I’ll leave my final decision until we do.

Flex Everywhere!

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So, my 6 year old HP printer “died” the other day (a.k.a. the printer head carriage system got buggered up), and at a quick stop at the CompUSA ‘Estate Sale’, I picked up a new HP D5360.  Seems to be a nice printer — although the old one really set my expectations high.  One thing I noticed is that the printer came with some software called the “HP Solutions Center v90″, which came with a familiar Flex loading screen…

Now, I doubt this is already an AIR app (I don’t think Adobe would let them publish beta software as drivers), so it must be using something else to bake the .EXE files, and let it communicate with my printer..  But, wow, that’s cool!

What Labs gave us for Christmas

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Better head over to Adobe Labs!  Today Adobe announced lots of new stuff:

  • Beta 3 of the Flex 3, Flex 3 Builder – The latest, and very polished versions of the Builder and runtime leading up to the final release of Flex 3.
  • Beta 3 of the AIR Runtime — Now with the final API’s named and placed, it is time to start building those AIR apps!  For those who don’t know what AIR is, it is an SDK that allows you to take your existing AJAX or Flex apps and make them desktop applications (browserless), in a Operating System agnostic way.  It also bring offline synchronization, filesystem and clipboard access to your applications as well.
  • BlazeDS — Adobe had decided to open-source a large portion of LiveCycle Data Services ES (formerly Flex Data Services), including the AMF protocol! The new platform includes all the Messaging (send a message out to the “channel”, and all the other clients get it in real-time), and Remote Object functionality.  Cost is no longer any issue for those applications.  Data Services and Proxying are still apart of the real LDS (but remember, there is LDS Express Edition, which is free for a single CPU!)   With AMF being opened up to the world, people will be able to make fully-compatible application servers in little time. 

Well, I know what I’ll be doing this weekend!

Adobe.com Redesigned

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Well, it’s official :  The Adobe.com site has been relaunched as of this morning.  This is a big move, because since Macromedia and Adobe officially merged, their front page (and any other pages) simply took the layout and form of the old Macromedia site (which mind you, was redesigned a few years before the merge).  The new site is said to focus on content, rather than navigation like the previous sites, and follows their own design principals that they lay out in their own documentation.  Unfortunately, ColdFusion is again not listed in their “quick pick of products”, but it can be found using the drop-down menus. 

So long “Halo”, welcome “UnNamed Design!”

Mapping in Flex

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Modest MapsMapping for me has always been one of those things that just wasn’t interesting, and well, something my apps just didn’t need.  Now I’ve got two apps in the hopper, and both could benefit from a mapping solution. Since my University has their own staff that is responsible for GIS, I thought the way to go was to tap into their database to display a campus map. I saw a demo from ArcGIS at the original 360|Flex back in the spring, and got really excited.  The component that was shown was in Beta, and so I waited.

In doing some research, I recently ran across a project called modest maps, which lets you implement 3rd party mapping solutions (Yahoo! Maps ,Goggle Maps, and Microsoft Live Earth), in addition to some open source maps and lets you place them right in your app.  What is neat about it is it takes the map tiles directly from the 3rd party and renders them in your app, making it seamlessly.  Completely awesome!  I simply had to import the ActionScript into my project, and drag-and-drop the map component into my canvas.  It really was that easy. Even though the project isn’t done (but according to their trac, they are close to 1.0), it seems to work very well.

I’ll write about it even more as I get closer to putting this app into production.. 

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