CS601 Quiz Set 3

In this data transfer is done as per patterns so there is a switch that will keep changing as per requirement and connect as per need like

We want 1 to 3 so at MUR it will connect with 1 and Demox will connected with 3rd slot and data will be transferred as per required

Main advantage is we will get rid of cross points.

Data-Link Layer

In case of physical link all links are logical

The internet is combination of networks.

If a packets is to travel from a host to another host it needs to pass through these networks

Data Link Layer controls Node-to-Node Communication

Data link exist btw physical layer and network layer.

It provide services to network layer and take services from physical layer.

Communication at the Data Link Layer

Let we have sending which is alise it will connect with the Data link and that data link will communicate with R2 and like these routers will communicate with each other with the help of data links.

Nodes and Links in Data Link Layer:

As in Data link layer communication is node to node.

Data unit from one point needs to pass through multiple networks ( LAN and WANS) to reach another point or Host.

Hosts and in connecting devices are nodes and these nodes are connected through the links.

Hosts and all the connecting devices are nodes.

Links = Network that are connecting these nodes are links Services That are provided by Data-Link Layer.

It provides services to network layer and receive from physical layers.

Services:

Framing: (Data Link receive data in form of Packets, then First task of data link is to divide these packets into frames) Flow Control: (Transfering needs flow control to manage speed of data creation and data consumption) Error Control: It consist of Error Detection and then Error Correction Congestion Control: It happens at Transfer of the data.

Process in Framing:

Encapsulation and Decapsulation

Data Link Receives data into packets and then it encapsulates into multiple frames. And then at receiving end it decapsulate the frames into packet and transfer it to next layer.

Example: A Communication with only Three Nodes.

Our Datagram or Frames do have Header which is 2 in the following photo