What is Data Link Layer Switching
Network switching is the process of forwarding data frames or packets from one port to another leading to data transmission from source to destination. The second layer of the Open System Interconnections (OSI) model, known as the data link layer, is responsible for dividing the physical layer’s bitstream into data frames and transmitting those frames in accordance with switching requirements. Bridges are network devices that perform switching at the data link layer.
Bridges
To create a larger local area network (LAN), a data link layer bridge joins several smaller LANs. Network bridging is the term used to describe this network aggregation process. The various parts are connected by a bridge, making them appear to be a single network.
Switching by Bridges
The data link address, or more specifically the MAC address, of a data frame is examined by a bridge when it arrives at a specific port. The bridge sends the frame to the intended port if the destination address and necessary switching are both correct. If not, the frame is thrown away.
End-to-end data transfer is not the responsibility of the bridge. From one hop to the next, the data frame must be transmitted. As a result, they do not check the frame’s payload field. They can assist in switching any kind of packet from the network layer above as a result.
Bridges also connect virtual LANs (VLANs) to make a larger VLAN.
A wireless bridge is used to handle the switching if any wireless segments of the bridged network exist.
There are three main ways for bridging −
- simple bridging
- multi-port bridging
- learning or transparent bridging
Switching
- Messages are sent through the network of transmission media when a user accesses the internet or another computer network from a location other than their immediate area. Switching is the term used to describe this method of moving data between computer networks.
- Switches are used to perform switching in computer networks. A switch is a discrete piece of hardware that connects various computers to a single local area network.
- In the OSI model, network switches operate at layer 2 (Data link layer).
- Switching is transparent to the user and doesn’t need the home network to be configured.
- On the basis of MAC addresses, switches are used to forward the packets.
- To transfer the data only to the addressed device, a switch is used. To properly route the packet, it validates the destination address.
- It is operated in full duplex mode.
- Since the source and destination are communicating directly, packet collision is minimal.
- It does not broadcast the message as it works with limited bandwidth.
Why Switching Concept is required
Switching concept is developed because of the following reasons:
- Bandwidth: It is described as a cable’s maximum transfer rate. It is a valuable but pricey resource. As a result, switching techniques are used to efficiently utilise a network’s bandwidth.
- Collision: When multiple devices transmit data over the same physical medium and collide with one another, the effect is called collision. Switching technology is used to prevent packet collisions in order to solve this problem.
Advantages of Switching
- Switch increases the bandwidth of the network.
- Since only the device that has been addressed receives the information, it lessens the workload on individual PCs.
- Since only the device that has been addressed receives the information, it lessens the workload on individual PCs.
- As the switch creates the collision domain for each connection, there will be fewer frame collisions.
Disadvantages of Switching
- A Switch is more expensive than network bridges.
- A Switch cannot determine the network connectivity issues easily.
- Multicast packet handling requires proper switch design and configuration.