Encapsulation of application data carried by UDP to a link protocol frame The Internet Protocol is responsible for addressing host interfaces, encapsulating data into datagrams (including fragmentation and reassembly) and routing datagrams from a source host interface to a destination host interface across one or more IP networks.[2] For these purposes, the Internet Protocol defines the format of packets and provides an addressing system. Each datagram has two components: a header and a payload. The IP header includes source IP address, destination IP address, and other metadata needed to route and deliver the datagram. The payload is the data that is transported. This method of nesting the data payload in a packet with a header is called encapsulation. IP addressing entails the assignment of IP addresses and associated parameters to host interfaces. The address space is divided into subnetworks, involving the designation of network prefixes. IP routing is performed by all hosts, as well as routers, whose main function is to transport packets across network boundaries. Routers communicate with one another via specially designed routing protocols, either interior gateway protocols or exterior gateway protocols, as needed for the topology of the network.[3] Version history[edit]A timeline for the development of the transmission control Protocol TCP and Internet Protocol IP. In May 1974, the Institute of Electrical and Electronics Engineers (IEEE) published a paper entitled "A Protocol for Packet Network Intercommunication".[4] The paper's authors, Vint Cerf and Bob Kahn, described an internetworking protocol for sharing resources using packet switching among network nodes. A central control component of this model was the "Transmission Control Program" that incorporated both connection-oriented links and datagram services between hosts. The monolithic Transmission Control Program was later divided into a modular architecture consisting of the Transmission Control Protocol and User Datagram Protocol at the transport layer and the Internet Protocol at the internet layer. The model became known as the Department of Defense (DoD) Internet Model and Internet protocol suite, and informally as TCP/IP. IP versions 1 to 3 were experimental versions, designed between 1973 and 1978.[5] The following Internet Experiment Note (IEN) documents describe version 3 of the Internet Protocol, prior to the modern version of IPv4:
The dominant internetworking protocol in the Internet Layer in use is IPv4; the number 4 identifies the protocol version, carried in every IP datagram. IPv4 is described in RFC 791 (1981). Versions 2 and 3, and a draft of version 4, allowed an address length of up to 128 bits,[6] but this was mistakenly[citation needed] reduced to 32 bits in the final version of IPv4. Version number 5 was used by the Internet Stream Protocol, an experimental streaming protocol that was not adopted.[5] The successor to IPv4 is IPv6. IPv6 was a result of several years of experimentation and dialog during which various protocol models were proposed, such as TP/IX (RFC 1475), PIP (RFC 1621) and TUBA (TCP and UDP with Bigger Addresses, RFC 1347). Its most prominent difference from version 4 is the size of the addresses. While IPv4 uses 32 bits for addressing, yielding c. 4.3 billion (4.3×109) addresses, IPv6 uses 128-bit addresses providing c. 3.4×1038 addresses. Although adoption of IPv6 has been slow, as of September 2021, most countries in the world show significant adoption of IPv6,[7] with over 35% of Google's traffic being carried over IPv6 connections.[8] However, server support for IPv6 is uncommon even among technology companies. Outside of Google, Facebook, Netflix, and some CDNs, few other server operators have adopted IPv6. As of October 2022, neither microsoft.com, amazon.com nor apple.com possess AAAA records, IPv6 redirect servers to their www domain, or IPv6-capable MX records, required for IPv6 to operate correctly. Most do not have IPv6-capable DNS servers. The assignment of the new protocol as IPv6 was uncertain until due diligence assured that IPv6 had not been used previously.[9] Other Internet Layer protocols have been assigned version numbers,[10] such as 7 (IP/TX), 8 and 9 (historic). Notably, on April 1, 1994, the IETF published an April Fools' Day joke about IPv9.[11] IPv9 was also used in an alternate proposed address space expansion called TUBA.[12] A 2004 Chinese proposal for an "IPv9" protocol appears to be unrelated to all of these, and is not endorsed by the IETF. Reliability[edit]The design of the Internet protocol suite adheres to the end-to-end principle, a concept adapted from the CYCLADES project. Under the end-to-end principle, the network infrastructure is considered inherently unreliable at any single network element or transmission medium and is dynamic in terms of the availability of links and nodes. No central monitoring or performance measurement facility exists that tracks or maintains the state of the network. For the benefit of reducing network complexity, the intelligence in the network is purposely located in the end nodes.[13] As a consequence of this design, the Internet Protocol only provides best-effort delivery and its service is characterized as unreliable. In network architectural parlance, it is a connectionless protocol, in contrast to connection-oriented communication. Various fault conditions may occur, such as data corruption, packet loss and duplication. Because routing is dynamic, meaning every packet is treated independently, and because the network maintains no state based on the path of prior packets, different packets may be routed to the same destination via different paths, resulting in out-of-order delivery to the receiver. All fault conditions in the network must be detected and compensated by the participating end nodes. The upper layer protocols of the Internet protocol suite are responsible for resolving reliability issues. For example, a host may buffer network data to ensure correct ordering before the data is delivered to an application. IPv4 provides safeguards to ensure that the header of an IP packet is error-free. A routing node discards packets that fail a header checksum test. Although the Internet Control Message Protocol (ICMP) provides notification of errors, a routing node is not required to notify either end node of errors. IPv6, by contrast, operates without header checksums, since current link layer technology is assumed to provide sufficient error detection.[14][15] Link capacity and capability[edit]The dynamic nature of the Internet and the diversity of its components provide no guarantee that any particular path is actually capable of, or suitable for, performing the data transmission requested. One of the technical constraints is the size of data packets possible on a given link. Facilities exist to examine the maximum transmission unit (MTU) size of the local link and Path MTU Discovery can be used for the entire intended path to the destination.[16] The IPv4 internetworking layer automatically fragments a datagram into smaller units for transmission when the link MTU is exceeded. IP provides re-ordering of fragments received out of order.[17] An IPv6 network does not perform fragmentation in network elements, but requires end hosts and higher-layer protocols to avoid exceeding the path MTU.[18] The Transmission Control Protocol (TCP) is an example of a protocol that adjusts its segment size to be smaller than the MTU. The User Datagram Protocol (UDP) and ICMP disregard MTU size, thereby forcing IP to fragment oversized datagrams.[19] Security[edit]During the design phase of the ARPANET and the early Internet, the security aspects and needs of a public, international network could not be adequately anticipated. Consequently, many Internet protocols exhibited vulnerabilities highlighted by network attacks and later security assessments. In 2008, a thorough security assessment and proposed mitigation of problems was published.[20] The IETF has been pursuing further studies.[21] See also[edit]
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What is the primary infrastructure that creates Internet?The backbone of the Internet, that part serviced by Network Service Providers and Backbone Providers, is constructed using a fiber optic cable infrastructure.
Which is the following protocol is the primary infrastructure that creates?Which of the following protocols is the primary infrastructure that creates the Internet? TCP/IP; The TCP/IP protocol is what allowed computers to share information outside their network, which stemmed the creation of the Internet as we know it today.
Which protocol is used to handle delivery of information from one network to another?Transmission Control Protocol (TCP) is a standard that defines how to establish and maintain a network conversation by which applications can exchange data. TCP works with the Internet Protocol (IP), which defines how computers send packets of data to each other.
Which of the following can connect directly to the Internet?Internet users are one of those who can connect directly to the Internet. Internet Users : A direct connection occurs when one computer is connected to another computer using a cable rather than through an Internet user. When compared to using a network, this type of connection is usually quicker.
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