Internet Layer

The group of internetworking methods in the Internet protocol suite, which is commonly called as TCP/IP, which is the foundation of Internet, is termed as Internet Layer. Internet layer is the concept of interconnecting multiple networks with each other through gateways. The Internet layer derives its name from facilitating internetworking or from its function of forming an internet. It is group of protocols used to carrying datagram packets from its originating Host across network boundaries.

The Internet layer never encompasses the protocols which describes the communication between local network nods. This local network node normally fulfill the purpose of maintaining link states between local nodes such as local topology, and that use the protocols, which is based on the framing of packets specific to the link types and this kind of protocols belongs to the Link layer.

Purpose of Internet layer

 The three basic functions of Internet layer: For outgoing packets, select the next-hop host and transmit the packet to this host by passing it to the appropriate Link layer implementation; for incoming packets, capture packets and pass the packet payload up to the appropriate transport layer protocol, if it is appropriate. In addition to this, it provides error detection and problem-solving capability.

The Internet layer is not responsible for the reliable transmission in its operation. It provides unreliable service and best effort delivery. It shows that the network makes no guarantees about packets proper arrival. It is the important design principle and change from the previous protocols which was used on the early ARPANET. From then the packet delivery across diverse network is unreliable and failure operation, the trouble of providing reliability was placed with the communication path, i.e. the hosts, rather than on the network. 

IP

Internet protocol is the main protocol in the Internet Layer of the internet protocol suite. It has the duty of transferring datagrams from the source host to the destination host, purely based on addresses. For this, IP briefs the addressing methods and structures for datagram encapsulation.

ICMP

The Internet control message protocol is one of the main protocols of the Internet protocol suite. To send the error message indicating, it is mainly used by the operating systems of networked computers. The ICMP can also used to communicate the query messages, that a requested service is not available or that a host could not be reached. ICMP for the internet protocol version 4 (IPv4) is also known as ICMPv4 and IPv6 has a similar protocol, ICMPv6.

Questions:

• What is Internet layer?
• What is IP and what is its task?