Tag Archives : Diagrams


Adventures in Home Networking II

Welcome back to ‘Adventures in Home Networking’ – Part 2. 

Recently, due to changes in our household, we were forced to consider making some physical changes to the way the house was set up.  A decision was reached to move my home office into one of the bedrooms, so that it could be closed/sealed off by a single doorway; to prevent our young baby from access to potentially swallowable items on low shelves.

This change induced some necessary changes to the home networking infrastructure.  The main ADSL router, which also acted as a gigabit switch, needed to stay in place (due to wiring of the house, only two telephone jacks are properly wired for DSL).

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A new, top-of-the-line Netgear wireless router/switch (also gigabit) was purchased and added to the networking gear in my office.  The 500mb/s D-Link PowerLine adapters are used to network the WWW-enabled router to the office router.

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Home Configuration (Current)

So there are two main WLAN access points, both wireless routers are dual band (2.4 GHz and 5 GHz) and allow for up to 300 Mpbs (router A) and 450 Mpbs (router B).  The WLAN coverage is pretty consistent, with both being detected at the rear of the property.  The picture above merely illustrates the intention – actual coverage is better.

The main problem was how to facilitate the kitchen area where there is a large concentration of electrical interference.  Placing the WLANs on either side of the kitchen means that wireless devices can connect to the closest access point.


Quick Sequence Diagram Editor

Not long ago, I posed a question to the Stack Overflow community – (is there a) “Good Visio Template (or alternative) for SOA/Distributed Systems?”.  Surprisingly, there was only one response!

Since then, I have been recently introduced to, of all things, a Java based tool called the ‘Quick Sequence Diagram Editor’ which can be used to produce really useful UML Call Sequence Diagrams.  Using this tool, you can effectively call out the interface definitions of your distributed services or service library.

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The tool uses a pseudo code syntax to produce (render) the sequence diagrams.  Services (or classes) are declared first , and then subsequent code calls out the service behaviour (request/response, arguments).  It also supports inline annotations (comments) as well as conditional (branching) IF/ELSE logic.

Code is evaluated/rendered as you add the code so that it is impossible to model a sequence with invalid object names.

From the site, here are the principal features:

  • The diagram changes as you type.
  • Diagram code is instantly checked, errors are pointed at.
  • Diagrams can be exported and zoomed.
  • Long diagrams can be paginated.
  • There are constraints imposed on diagram specifications, so one cannot model something that is impossible to implement.

All it requires is Java (for your platform), the downloadable is an executable .jar file which consumes the specification files (which can be used with other UML document tools as well).

Enjoy

Download: http://sourceforge.net/projects/sdedit/