Week 2 Individual Assignment

Week 2: Individual Assignment

Christopher Hamer

NTC/249

April 6, 2015

Layering is a structuring technique that is widely accepted and was chosen by ISO. Each layer performs functions that are a related subset that are required to be able to communicate with another system. Layering depends on the layer lower to it to complete its specialized functions before the next layer can complete its specialized functions. The lower layer also provides services to the next layer up to be able to complete its job and if changes need to occur then it does not mean that changes need to occur in every layer just the one that needs it. Each layer has a set of functions and services that need to be performed only in each layer (Stallings. 2013). We are going to discuss different layers that operate on WAN protocols and what are those protocols. We will discuss the layers that routers and switches operate on and if routers reside at more than one layer.

WAN protocols operate on the lowest three layer of the OSI model; network layers, data link layers, and physical layers (Davis, 2009). The physical layer deals with the transmission of unstructured bit stream over a physical medium, it also deals with the electrical, mechanical, procedural, and functional characteristics to be able to reach the physical medium (Davis, 2009). Now the data link layer is concerned with the reliable transfer of information across the physical link, it also sends blocks that have synchronization, flow and error control. Last the network layer, establishes, maintains and terminates connections. This layer makes it better for the layers above it to not be dependent on the data transmission and switching technology used to connect systems (Stallings. 2013).

Three of the WAN protocols people should know about are the HDLC, PPP, and Frame-Relay. I will start with the HDLC protocol, HDLC stands for High-level data link control protocol (Davis, 2009). The HDLC protocol operates on the data link layer....