This packet exchange between two hosts requires a diversity of protocols that must exist at the Data Link layer. Although the two hosts may be communicating with their peer Network layer protocols (IP for example), it is likely that numerous Data Link layer protocols are being used to transport the IP packets over various types of LANs and WANs.
#What re the eleme ts of the ppp frame Pc#
Imagine a data conversation between two distant hosts, such as a PC in Paris with an Internet server in Japan. At each hop along the path, an intermediary device - usually a router - accepts frames from a medium, decapsulates the frame, and then forwards the packet in a new frame appropriate to the medium of that segment of the physical network. In any given exchange of Network layer packets, there may be numerous Data Link layer and media transitions. This layer provides services to support the communication processes for each medium over which data is to be transmitted. The Data Link layer relieves the upper layers from the responsibility of putting data on the network and receiving data from the network. Sometimes, a physical network is also referred to as a network segment.Īs we have discussed, a network model allows each layer to function with minimal concern for the roles of the other layers.
Physical networks represent the interconnection of devices on a common media. Logical networks are defined at the Network layer by the arrangement of the hierarchical addressing scheme. ** A physical network is different from a logical network. In this chapter media does not refer to content programming such as audio, animation, television, and video as used when referring to digital content and multimedia. Media is the physical copper cable, optical fiber, or atmosphere through which the signals travel. Here, these words refer to the material that actually carries the signals representing the transmitted data. * It is important to understand the meaning of the words medium and media within the context of this chapter. The Data Link layer is responsible for the exchange of frames between nodes over the media of a physical network. Network (physical)** - Two or more nodes connected to a common medium Media/medium (physical)* - The physical means for the transfer of information between two nodes Node - The Layer 2 notation for network devices connected to a common medium
0 kommentar(er)
