Network Layer Design Issues
Network layer does the following functions:
- It maintains the address at the frame header and does the addressing to detect devices in the network.
- The packets from the upper layer are converted by the network layer.
- It also chooses the best path for the data transmission from the source to the destination.
- The network layer delivers a logical connection across multiple devices.
The Network layer design issues are as follows:
- Store and Forward packet switching
The host sends packets to the nearest router, the packet is stored there till it is fully processed by verifying the checksum, then it is shifted to the next router till it reaches the destination.
- Services provided to Transport layer
The network layer provides the following services to the transport layer:
- Connectionless: Where the routing and insertion are done individually, and no set-up is required.
- Connection-oriented: All the packets are transmitted through a single route.
- Implementation of connectionless service
If there is a situation where the message size that needs to be transmitted is four times the size of the packet, then the Network layer divides it into 4 packets and then transmits each packet to a router.
- Implementation of connection-oriented service
In this, a connection is established first. Then it is used and released. The data packets are transmitted to the receiver by the same route as it is sent by the sender. It can be done by two methods:
- Circuit Switch Connection: A circuit is established between the connecting nodes.
- Virtual Switched Connection: A virtual path is established between the connecting nodes.