What Is Contained In The Trailer Of A Data-Link Frame?

What Is Contained In The Trailer Of A Data-Link Frame?

The Trailer of a data link frame has all the information about error detection. Today, let us look a closure look into the data link layer. The Data link layer is the second layer of the OSI model. The data link layer is mainly responsible for the transferring of the data between the two hosts.

These hosts are directly linked via a network. The data link layer will offer a service called framing. Now, let us learn the concepts of framing in detail. Let us take an example to understand this concept in detail. Let say, we have two devices that are connected through each other. Each has a device, that has an adapter connected to it. This adapter is used to transmit the information between the two devices. Whatever information that we receive from the data link layer, will be converted in the form of signals.

This kind of cable can be transmitted through a medium, which is then received at the physical layer of the OSI model. Now, the main problem here is that the application which has the information will transmit the data in the form of the zeros and the ones. It converts into the transport layer.

In the transport layer, the will add some of the zeroes, ones, and then it transfers to the network layer of the OSI model. After the network layer, it will be gone to the data link layer, in the data link layer, we will add some sets of the zeroes and ones at the header and the trailer part. This addition of zeroes and ones at header and trailer, we call it as the frame.

These frames can only be understood by the data link layer. All the frames will transmit from the host to the host. The framing consists of a header, data, and the trailer part as shown in the below figure 1.1. Here the header part consists of the frame start, its types, quality control and add. And the trailer consists of error detection and the frame stop. And in the middle, we have the exact data which we need to send.

Simply, between the two devices, when they want to communicate with each other knowingly, we use the frame. These frames set a header and trailer at the end of each data in order to get clarity to the receiver where the data gets ended. The header and trailer contain the same information so that the receiver knows the set of information present in a frame.

At the trailer part, we can also find the detection of the errors along with the trailer part. The detection of errors has two techniques, we add some group of bits at the end of the data. So that we can able to detect the errors, another method is the exact count encoding. The below figure shows the format of the data link frame and the sub parts of the data link frame.

1.1