The network layer is responsible for routing data across networks, and there are several design issues and concepts associated with it. Here’s an explanation of the points you mentioned:
- Store and Forward Packet Switching:
In packet switching networks, data is divided into smaller units called packets. At each intermediate node (router or switch), the entire packet is received, stored briefly in a buffer, and then forwarded to the next node on the path towards its destination. This process is known as store and forward packet switching. - Services Provided to the Transport Layer:
- The network layer services should been designed with the following goals in mind.
- –The services should be independent of the router technology
- –The transport layer should be shielded from the number, type, and topology of the routers present.
- –The network addresses made available to the transport layer should use a uniform numbering plan, even cross LANs and WANs
- Two types of network layer services:
- –Connection oriented service vs connected less service
- Implementation of Connectionless Service:
The network layer can implement a connectionless service, which is a datagram service like the User Datagram Protocol (UDP). In a connectionless service, each packet is treated independently, and there is no prior setup or teardown of a dedicated end-to-end path. Packets are routed individually based on their destination address. - Implementation of Connection-Oriented Service:
Alternatively, the network layer can implement a connection-oriented service, which is a virtual circuit service like the one provided by the Internet Protocol (IP) in combination with protocols like TCP. In a connection-oriented service, a logical connection or virtual circuit is established between the source and destination before data transfer begins. This connection ensures that packets follow the same path and arrive in the correct order. - Comparison of Virtual Circuit and Datagram Subnets:
