Tuesday, January 10, 2012

Networking Part 2: Devices

Media is what data travels through.  There are three main types of media: Copper, Fiber (glass), and Air.
    Copper: Signal can travel 300 meters unrepeated.
    Fiber: Signal can travel 3000 meters unrepeated in single mode, 2000 meters unrepeated in multi mode.
    Air- Signal can travel 300 meters unrepeated.


Repeater- Retimes and regenerates networks signals
Hub- multi-port repeater, huge collision domain
    Collision Domain- Area where collisions occur
Bridge- Filters traffic based on physical addresses (MAC addresses)
Switch- multi-port bridge with lots of collision domains
    Micro Segmentation- Create a lot of collision domains
Router- routes data packets based on IP address
    IP- Internet Protocol Address
NIC- Network Interface Card.  This gives you your digital "fingerprint"

Switches are much better than repeaters, hubs, and bridges.  They do everything the first three do, except with less problems.  Since they have a lot of small collision domains instead of one huge one (like a hub), there is less chance a collision will occur.

Monday, January 9, 2012

My First Flash Movie

This is my first Flash movie for my Communications Technology class.


Bits, Cookies, Bytes, RAM, Static, Dynamic, Compression, HTTP, HTTPS.
All familiar terms, popping up while you play around on your computer.  For me, at least.
Now I know what they mean... Sort of.  Let's find out what these common network terms mean.

Bits are the smallest unit of information.  Cookies are 4 bits and Bytes are 8 bits.

RAM is Random Access Memory, which is what your computer uses whenever you have applications open.  If your computer's slow, this is usually one of the main reasons- you're clogging up your RAM space.

Static means unchanging, and dynamic means changing.  Static is the reason everything you do on the internet can be traced.  A URL is dynamic.

Compression happens when you shrink data.  You can compress images or files so they take up less memory.

HTTP is hyper text transfer protocol, and HTTPS is basically the same, except it's secure (see the S on the end)

Some less familiar terms (for me, anyway): Node, Encapsulation, De encapsulation, Encryption, FTP, Bandwidth, Throughput.

Node- network ready device
Encapsulation- wrapping of data
De encapsulation- very obvious if you know encapsulation, it means unwrapping of data
Encryption- securing data
FTP- file transfer protocol
Bandwidth- maximum amount of data that can travel at a given time
Throughput- actual amount of data traveling at a given time (always less)

OSI is a seven layered reference model.  It goes as follows:
    7) Application (browsers, email) Data
    6) Presentation (common data format, encryption and compression) Data
    5) Session (virtual session, end-to-end conversations like facebook chat) Data
    4) Transport (quality of service, flow control) Segments
    3) Network (routing, logical/dynamic IP addressing) Packets
    2) Data Link (MAC Address- not the computer, media access control-/Physical Static address) Frames
    1) Physical (bits, binary, voltage) Bits

There is an introduction to networking.  Not too confusing, I hope, but these are just the basics.