The original definition of the end-to-end principle assigned the maintenance of state and overall intelligence at the edges of the network and that the Internet would connect these edges while focusing on simplicity and speed. The lowest layer of IP, it is used to move data packets between the Internet Layer interfaces of two hosts on the same link.
Information can be transported that relates to a number of upper layer protocols which are identified by a unique protocol number. The network layer implements logical addressing for data packets to distinguish between the source and destination networks.
The OSI model is widely criticized for an inherent implementation complexity that renders networking operations as inefficient and slow. While Generic Routing Encapsulation GRE might seem to be a network-layer protocol, if the encapsulation of the payload takes place only at the endpoint, GRE becomes closer to a transport protocol that uses IP headers but contains complete Layer 2 frames or Layer 3 packets to deliver to the endpoint.
In the OSI model, this layer is responsible for gracefully closing a session, which is handled in the Transmission Control Protocol at the transport layer in the Internet Protocol Suite.
The protocol can also not support internetwork traffic because it cannot route traffic between networks.