Wow, is all I can say. What a great conference. This was my first time at the CTIA conference and I was very impressed. This was a massive show, tens of thousands in attendance. I’ve already signed up for my CCIE wireless written exam and am ready to start my journey in the wireless arena – 3G/4G, DAS, and WiFi will be on my resume in the near future.

Small Cell and Wifi offload were big topics as well as spectrum availability. The FCC chairman discussed the spectrum issues and today Bill Clinton gave the keynote. The CEO panel discussion/keynote was also very interesting but a little too high-level, pie-in-the-sky, for me.

The short of it. Consumer mobile bandwidth demand is increasing at a staggering rate, if nothing is done demand will surpass supply by 2014. Of course nobody is going to sit idly by and do nothing. In order to keep up with that bandwidth demand the coverage area or “cell” needs to get smaller, supporting less users, but increasing overall bandwidth for those users. There were a lot of small cell products being touted at the show. These are basically small base stations with all of the necessary components built-in. Mount and power and plug-in your backhaul.

Another component of the solution is WiFi offload. Currently most smart mobile devices like tablets and smartphones have built-in 3G/4G radios as well as WiFi radios. When both are active in most cases the device puts the data over the WiFi and the voice over the cellular side – whether the actually quality of service on the WiFi is better than the 3G/4G or not. Part of the offload solution is to begin building in intelligent routing algorithms into the devices that make network selection decisions based on quality of service and bandwidth availability. In other words, make use of the best available network based on dynamic quality measurements.

More to come as I get more and more into the service provider/carrier grade wireless networks.


The basic building block of IPv6 is the IPv6 packet header. Unlike IPv4, IPv6 uses a fixed length packet header. This improves processing efficiency of routing devices that the packet traverses through.

The illustration above shows the difference between an IPv4 header and an IPv6 header. You notice there isn’t a header length field in the IPv6 header. The header is always 40 octets (bytes) long.

Version (4 bits) – Always set to 0110 (6) representing version 6
Traffic Class (8 bits) – Most significant 6 bits are used for DSCP; 2 other bits used for ECN
Flow Label (20 bits) – First uses of this field are still emerging
Payload Length (16 bits) - size of payload in octets. Includes extension headers.
Next header (8 bits) – Indicates an IPv6 extension header or another header such as TCP or UDP header
Hop limit (8 bits) – Replaces TTL field. Each intermediate hop decrement this field by one. If it hits 0 the packet is dropped.
Source Address (128 bits) – Source IPv6 address
Destination Address (128 bits) – Destination IPv6 address

There is a great article in the TCP/IP Guide regarding encapsulation that is a must read as well. You can see where the IPv6 header fits in the packet encapsulation process.

Now that you have an idea of what an IPv6 header looks like we will cover the 128-bit IPv6 address in our next article.




After upgrading my MBP to Snow Leopard and now to Lion I had issues using CTC on Mac OS X (10.6+). CTC is a complex java applet ran through a browser that requires access to the $HOME directory of the user. It creates a .ctc directory in the $HOME directory and stores various .jar files.

Since upgrading OS X the security features of the Java runtime environment prevented the automatic download and execution of the .jar files. This short tutorial goes through getting CTC to launch on Mac OS X, although the process is a little manual, it doesn’t take much time.

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