TCP/IP Network Interface Layer

Network Interface layer is the lowest layer in TCP/IP model. The protocols in this layer provide the means of transferring the data between the host and the network.

Network Interface Layer describes the standards for physical media and electrical signaling during communication process. Network interface layer is used to connect host computer which is not a part of network to the network. Some of the standards defined by network interface layer are Ethernet, Token Ring FDDI and frame Relay. Ethernet defines the required cabling, addressing and protocols.

TCP/IP network interface provides services to the layer above it. Internet protocol used at network interface layer delivers IP packets across the physical network. Internet protocol recognizes the topologies, how host computer is linked to the network and it also understands the IP addressing schema.

Network Interface layer includes number of protocols like Ethernet and other LAN standards. It also includes some of the well known WAN standards such as Point-to-point protocol (PPP) and frame Reply.

Let’s taken an example to explain how IP transfers data from John wants to send the IP packet, he does it by sending it to R2. John adds Ethernet header and trailer to send it to R2. At R2, the headers and trailers are stripped off from the IP packet. To transmit the packet from R2to R1, PPP serial link is used; R2adds its own PPP header and trailer. When R1 receives the IP packet, it removes PPP headers and trailers. Then R1 send the packet over the Ethernet to Ruby. R1 accomplishes this task by adding its own header and trailer and forwards the packet to Ruby.

IP uses network interface protocol to deliver the packet to intended host. Each router repeats the process until the IP packet is delivered to desired destination station. Network interface layer uses header to encoder to the data which is required the data across the physical network.