How Networks Work

I found a really good video which explains how data is travelled in the network. This explains in simple words with animation about the tasks done by the following main components and more.

• Packet
• Router
• Switch
• Firewall

If anyone is interested in networking I highly recommend you to watch this.

Determining the Network

In the BlackBerry project that I am in now we are having the requirement to detect the mobile network the phone is currently in.
Basically in BlackBerry mobile network is uniquely identified by the Mobile Country Code (MCC) and the Mobile Network Code (MNC).
To get these details from your code what you have to do is to call

RadioInfo.getMCC()
and
RadioInfo.getMNC()

These will return the codes in decimal.
You can find a full list of MNC codes of the mobile phone operators and a list of country codes by following the following URLSs to Wikipedia.
http://en.wikipedia.org/wiki/Mobile_Network_Code
http://en.wikipedia.org/wiki/Mobile_Country_Code

If you need to access the BlackBerry knowledge base article describing the above process you can follow the following link.
http://www.blackberry.com/knowledgecenterpublic/livelink.exe/fetch/2000/348583/800332/1467358/How_To_-_Determine_the_MCC_and_MNC_of_the_current_network.html?nodeid=1467359&vernum=0

Creating a Crossover Cable

A crossover cable is a special cable we use when we needs to connect two computers together directly. But the thing is when creating the crossover cable you have to create it properly. As of the name suggests we have to cross some cables when clipping the network cable.

The following image will show how to do the cross.

If you have additional time you can visit the following site which is a good site explaining different color code standards.
http://www.patraswireless.net/tutorial/basic%20tutorial/tut-equipemt/cable_utp.htm

If you already have an existing network cable and if you would like to make it a crossover cable, the following site will be useful since there you can change the wires (by changing the color drop down controls) as it is clipped in one end and can find out the way the other end needs to be clipped.

http://www.davidj.org/tools/cabler/cabler.html