This is usually done because of the requirements of the data transfer. For example, FTP (file transfer protocol) will use TCP for transport because we want to make sure the data was transferred reliably. DNS will use UDP because we don't need the handshaking or connection based transport.
The transport layer uses port numbers to identify source and destination application layer protocols. Each application layer protocol is associated with a specific port number, allowing the transport layer to direct incoming and outgoing data to the correct application. For instance, HTTP typically uses port 80, while HTTPS uses port 443. This mechanism enables multiple applications to communicate simultaneously over a network without interference.
Once data is routed through the network and delivered to a specific host, it must be delivered to the correct user or process. As the data moves up or down the layers of TCP/IP, a mechanism is needed to deliver data to the correct protocols in each layer. The system must be able to combine data from many applications into a few transport protocols, and from the transport protocols into the Internet Protocol. Combining many sources of data into a single data stream is called multiplexing. Data arriving from the network must be demultiplexed, divided for delivery to multiple processes. To accomplish this, IP uses protocol numbers to identify transport protocols, and the transport protocols use port numbers to identify applications.
Layer 4, often referred to as the Transport Layer in the OSI model, does not have a specific historical occurrence but rather represents a conceptual framework for networking protocols. It encompasses the transport of data between devices, primarily utilizing protocols like TCP (Transmission Control Protocol) and UDP (User Datagram Protocol). The development of these protocols began in the 1970s, with TCP being standardized in 1981. Thus, layer 4 has been integral to networking since the early days of the internet.
Yes. Three examples are:HTTP - HyperText Transfer Protocol (used to transfer web pages)FTP - File Transfer Protocol (as it says)SMTP - Simple Mail Transfer Protocol (supports some functions of the email system)These are all service layer protocols. Underpinning these are transport layer protocols, principallyTCP - Transport Control Protocol (used for most services)UDP - User Datagram Protocol (used for services and internal internet mechanisms that favor unimpeded delivery over assurance, order, and/or control of data flow)There are layers of protocol below this; the immediate one is the internetwork layer, which allows the higher layers to work seamlessly over multiple interconnected network media such as WiFi, Ethernet, optical fiber, etc. Below that are the protocols that correspond to the specific media.
RIP and OSpf are non-proprietary protocoleigrp is a proprietary protocol i.e it is a vendor specific
The TCP/IP suite includes the following protocols Data Link Layer: ARP/RARP Address Resolution Protocol/Reverse Address DCAP Data Link Switching Client Access Protocol Network Layer: DHCP Dynamic Host Configuration Protocol DVMRP Distance Vector Multicast Routing Protocol ICMP/ICMPv6 Internet Control Message Protocol IGMP Internet Group Management Protocol IP Internet Protocol version 4 IPv6 Internet Protocol version 6 MARS Multicast Address Resolution Server PIM Protocol Independent Multicast-Sparse Mode (PIM-SM) RIP2 Routing Information Protocol RIPng for IPv6 Routing Information Protocol for IPv6 RSVP Resource ReSerVation setup Protocol VRRP Virtual Router Redundancy Protocol Transport Layer: ISTP Mobile IP Mobile IP Protocol RUDP Reliable UDP TALI Transport Adapter Layer Interface TCP Transmission Control Protocol UDP User Datagram Protocol Van Jacobson compressed TCP XOT X.25 over TCP Session Layer: BGMP Border Gateway Multicast Protocol Diameter DIS Distributed Interactive Simulation DNS Domain Name Service ISAKMP/IKE Internet Security Association and Key Management Protocol and Internet Key Exchange Protocol iSCSI Small Computer Systems Interface LDAP Lightweight Directory Access Protocol MZAP Multicast-Scope Zone Announcement Protocol NetBIOS/IP NetBIOS/IP for TCP/IP Environment Application Layer: COPS Common Open Policy Service FANP Flow Attribute Notification Protocol Finger User Information Protocol FTP File Transfer Protocol HTTP Hypertext Transfer Protocol IMAP4 Internet Message Access Protocol rev 4 IMPPpre/IMPPmes Instant Messaging and Presence Protocols IPDC IP Device Control IRC
The IP stack, also known as the Internet Protocol Suite, is a set of networking protocols that govern how data is transmitted over the internet. It is commonly organized into four layers: the application layer, transport layer, internet layer, and link layer. Each layer has its own specific functions and protocols, such as TCP and UDP at the transport layer and IP at the internet layer, enabling communication between devices across diverse networks. This layered architecture helps manage the complexities of data transmission and ensures interoperability among various network technologies.
Protocol independence means that an application or service is able to utilize more than one communications protocol. The most common protocol would be TCP/IP which actually encompasses different types of IP protocols such as IP or UDP. The TCP component is responsible for connection management and the IP component is the actual communications protocol. It is possible to use IP without the TCP component. This is also referred to as a connectionless protocol like UDP. These different types of IP communications could be considered different protocols. This could be an example protocol independence if either can be used for a specific application. There are less common protocols like Novell's IPX/SPX which do not interoperate with TCP/IP in any way. However, there are applications that can use either protocol making them completely protocol independent. Both TCP/IP and IPX followed the OSI model, and it is possible to load both protocols on the same network interface on a host, and even on a CISCO router as a sub-interface. Remember that the lower levels of the OSI model such as physical, data, network and transport are open and can be replaced with different media and or data frame size etc. Try to find a detailed OSI model and you will see more than one protocol within the transport layer. This would also help in understanding protocol independence. It is also possible to encapsulate or hide one protocol inside of another to allow say NetBIOS or IPX to be carried over an IP network within a pure IP packet. This requires that all the IP packet header and footer be stripped away and the inside or encapsulated protocol to be handed off to a higher OSI layer such as the Session layer. I forgot to login MPGMichael first answer
Application protocol layers that are specific to certain applications such as the World Wide Web (WWW), email, and FTP causes websites to appear on the computer screen.
Well-known communications protocols are Ethernet, a hardware and Link Layer standard that is ubiquitous in local area networks, and the Internet Protocol Suite, which defines a set of protocols for internetworking, i.e. for data communication between multiple networks, as well as host-to-host data transfer, and application-specific data transmission formats.
Connectionless Protocols: These protocols do not establish a connection between devices. As soon as a device has data to send to another, it just sends it. Answer:A Connectionless Protocol is a data communication method in which communication occurs between hosts with no previous setup. The device at one end of the communication transmits data to the other, without first ensuring that the recipient is available and ready to receive the data. The device sending a message simply sends it addressed to the intended recipient. The Internet Protocol (IP) and User Datagram Protocol (UDP) are connectionless protocols, but TCP/IP (the most common use of IP) is connection-oriented
Nonstandard protocol refers to a communication protocol or set of rules that deviates from commonly accepted standards. These protocols may be specific to certain systems or applications, making them incompatible with industry-wide specifications. Their use can pose interoperability issues and security risks.