Routers at this layer help do this efficiently. Layer 2: Data Link ... the OSI model is obsolete (due to its conceptual nature) and less important than the four layers of the TCP/IP model, Kumar ...

Ethernet is a layer 2 data link ... the TCP/IP protocol, which resides at layers 3 and 4. To understand network communications, it is essential to learn about the protocol layers (see OSI model).

One of the most widely used is the Transmission Control Protocol/Internet Protocol (TCP/IP ... layer (Fig. 1). 1. In the OSI model, data flows down the transmit layers, over the physical link ...