Surrey Hills in Spring

Photos from last weekend hike.

Mont Saint-Michel and Rouen

This Easter we made a road trip down to Rouen and Mont Saint-Michel in France.

Bletchley Park and the National Computer Musem

Day trip up to Bletchley Park and the National Computer Museum.

Memorial dedicated to the Polish code breakers

Working computer used to crack the codes

Control Panel

Paper storage

"Too Fast" Speed setting

Bournemouth

We went for a day trip down to Bournemouth.  The weather was amazing, just like in Summer.  Sadly the weather is now gone and it's the typical fog...

Little changing huts

Grand hotel from the Victorian Era

Downtown (or City Centre)

Beach and Boardwalk

Yes, this weather is once a year

Bournemouth from the cliff top

CISSP Done

After 4 month of studies, the CISSP exam is done and dusted.  What started as a plan last summer, and finally as something to complete during the winter is done.

The original plan started out a while back where I had some free time during a project.  I started looking through the books and course notes.  I was planning on looking into learning more about management and maintenance of security, and the CISSP is an excellent path to learn those topics.  Later in November, I did a little more planning and booked the exam for January.  The original plan was during winter break to study, but as always, there was little time and put it off.  Middle January I noticed I was not ready (and with my wife telling me I should use more time to study) I rebooked it to end of March.  It’s winter anyways and the weekends are cold, so it’s perfect to study.

Study plan was:
Conrad’s Blue CISSP book - perfect for getting through the scope of material.
Shon’s "All-in-One"Book - this book is terrible, but because it so badly written and jumps over the place, it’s a good study guide.  Don't use it at first.
CCure.com - This practice website is essential.  The last month I just hammered each section to average at 80%
Paper - I used two full note books of paper, writing down every little note and practice question.  This helps in slowing down and writing is the physical process of memorization.
Eat better - for the past two months I tried to eat as healthy as I can and also started cycling to work.

My Study plan was every Saturday I would go to the library and take a full 250 practice exam.  This is essential for two parts: One it prepares you for the full exam and second is simulates the duration of studies.  You should be able to complete a full exam with 80%

The actual exam is similar, obviously the questions are different.  The point is that they are not like Cisco or other exams.  You'll find only a handful of, “what port does POP use?” type of questions.  Most are along the lines of what would be the best solution from the organization’s perspective.

TCP Flow

Study notes from reviewing TCP and the basic components.

Segments are chunks of data that come into the TCP buffer.  A segment on the wire includes the data and headers.

Sequence numbers start with a random value (ISN) and are unidirectional.  The sequence number tracks the data flow and is used to track down what chuck of the flow is lost.

ACK's are the sequence number plus 1.

Windows size is a collection of sequence numbers and is used to track how much of the buffer the receiver can consume.  It slides is a scaling factor number (grows and the connection is stable and shrinks when drops occur).

Selective ACK's can group a range of packets to identify what was lost (this speeds up the flow of TCP).

TCP is also full-duplex, so the same steam is used for both directions, unlink IPSec SA's.

Economics

Here's an interesting article about Greenspan's new book.  It looks like Greenspan has now come to the conclusion that economics is not a hard science and can't be understood in simple tables.

TCP, HTTP and SPDY Protocols

Here's an interesting webcast by Ivan Pepelnjak on TCP, HTTP and the new protocol from Google called SPDY.

In short, the problem with many websites is that TCP was written back in the 1980's and not optimized for today's high-speed networks.  Add to the problem, HTTP was written also to be a universal protocol delivering many components for web sites.  Put these two together and you have a stack that works, but is not optimized for quick applications.  The solutions now days are to increase the presentation layer to be stateful in keeping connections open to clients for as long as they can (at the cost of memory on the servers) or have the clients process cookies and be slowed down as they reconnect.

Google's answer to the problem is to have a new session layer protocol that establishes connectivity quickly and has a low footprint, allowing legacy http applications to stay open and start-up fast.  The protocol is designed to work over a secure TLS layer without the additional overhead that the current TCP implementation has.

It's a good challenge to see if it works.  Initially the results are that the protocol is not that much faster, but with more light-weight appliances coming online that have built in web server interfaces, this may be a answer to bloated applications we see now.

London Waterloo Station

Here's a typical scene when there's a problem at Waterloo Station on Friday when people want to go home.  Good thing was that my wife and I were meeting at Waterloo to go out to dinner.

Imperial War Museum in Duxford

Some aircraft photos from the Duxford air museum.  Last time I was here I had a simple camera so the photos didn't come out there best, so this time I took my Nikon and 70-300mm to see what kind of photos I could get.

Concord control panel seen from outside

Concord cockpit from inside

Poland on a Spitfire

Polish Squadron 

A-10 Warthog - This aircraft is the ugliest thing to fly, but I like it!

Taking off from the airfield