There are many UTP cables for sale in your favorite computer store, but, it is good to know how to make them. First, there are two standards for the UTP cabling pinouts as defined by the TIA (Telecommunications Industry Association) as well as by EIA (Electronics Industry Alliance). These standards are called: T568A and T568B. Basically, they differ by the order of the wires attached to the RJ-45 connector. For both, T568A & T568B, the wires can be grouped in 4 pairs.
Read more…
The OSI Reference Model consists of 7 layers. When OSI was in active development, new protocols and specifications to implement the functions specified by each layer were made. Today, the OSI model can be used as a standard of comparison to other networking models (to TCP/IP, for example).
Let’s take a look in the OSI Reference Model layers:
7) Application.
It provides an interface between the communications software and any applications that need to communicate outside the computer on which the application resides. It also defines the authentication process.
Read more…
We finished our last post writing about the Transport Layer of the OSI Reference Model of the network. Now, I’m going to summarize the Internet & Network layers of such model.
Internet Layer.
The Internet layer primarily defines the Internet Protocol (IP) and defines IP addressing, so, that devices can have its own unique IP. In addition, the Internet layer defines the process of routing to let routers deliver packets of data to the correct destination.
The data encapsulated in the Internet layer is a called a packet.
Network Layer.
The Network access layer defines the hardware and protocols required to deliver data across some physical network. It includes all the variations of Ethernet protocols, PPP and Frame Relay.
The data including Ethernet header/trailer and PPP header/trailer in the Network layer is called a frame.
In a brief, the TCP/IP model consists of the following layers:
- Application
- Transport
- Internet
- Network Access
The next post of this CCNA crash course will about the OSI reference model of the network.
