The internet protocol works by splitting data into little chunks called datagrams or packets. The chunks are then sent across the internet from one IP address to another.
UDP stands for User Datagram Protocol. Recall that a datagram and a packet are more or less the same thing. UDP, also built on top of the IP protocol, works similarly to TCP, but is simpler and faster.
Humor TCP Data Vs UDP Data
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Hanselman said Data Expedition is unique for the general-purpose nature of its technology, which can be implemented in a relatively straightforward way. He cited other high-volume data transport protocols, such as XTP, that he said can be difficult to integrate.
The packet is the basic unit of information transferred across a network, consisting, at a minimum, of a header with the sending and receiving hosts' addresses, and a body with the data to be transferred. As the packet travels through the TCP/IP protocol stack, the protocols at each layer eitheradd or remove fields from the basic header. When a protocol on the sending host adds data to the packet header, the process is called data encapsulation. Moreover, each layer has a different term for the altered packet, as shown in the following figure.
Suppose the user issues an rlogin command to log in to the remote host, as shown in Figure 4-1. The rlogin command uses the TCP transport layer protocol. TCP expects to receive data in the form of a stream of bytes containing the informationin the command. Therefore, rlogin sends this data as a TCP stream.
TCP is often called a "connection-oriented" protocol because it ensures the successful delivery of data to the receiving host. Figure 4-1 shows how the TCP protocol receives the stream from the rlogin command. TCP divides the data received from theapplication layer into segments and attaches a header to each segment.
Segment headers contain sender and recipient ports, segment ordering information, and a data field known as a checksum. The TCP protocols on both hosts use the checksum data to determine whether data has transferred without error.
TCP uses segments to determine whether the receiving host is ready to receive the data. When the sending TCP wants to establish connections, it sends a segment called a SYN to the peer TCP protocol running on the receiving host. The receiving TCP returns a segment called an ACK to acknowledge thesuccessful receipt of the segment. The sending TCP sends another ACK segment, then proceeds to send the data. This exchange of control information is referred to as a three-way handshake.
UDP is a "connectionless" protocol. Unlike TCP, it does not check to make sure that data arrived at the receiving host. Instead, UDP takes the message received from the application layer and formats it into UDP packets. UDP attaches a header to each packet, whichcontains the sending and receiving host ports, a field with the length of the packet, and a checksum.
As shown in Figure 4-1, both TCP and UDP pass their segments and packets down to the Internet layer, where they are handled by the IP protocol. IP prepares them for delivery by formatting them into units called IP datagrams. IP then determines the IP addresses for the datagrams,so they can be delivered effectively to the receiving host.
IP attaches an IP header to the segment or packet's header in addition to the information added by TCP or UDP. Information in the IP header includes the IP addresses of the sending and receiving hosts, datagram length, and datagram sequence order. This information is providedin case the datagram exceeds the allowable byte size for network packets and must be fragmented.
Data-link layer protocols, such as PPP, format the IP datagram into a frame. They attach a third header and a footer to "frame" the datagram. The frame header includes a cyclical redundancy check (CRC) field that checks for errors as the frametravels over the network media. Then the data-link layer passes the frame to the physical layer.
Internet Layer reads information in the header to identify the transmission and determine if it is a fragment. If the transmission was fragmented, IP reassembles the fragments into the original datagram. It then strips off the IP header and passes the datagram on to transportlayer protocols.
Transport Layer (TCP and UDP) reads the header to determine which application layer protocol must receive the data. Then TCP or UDP strips off its related header and sends the message or stream up to the receiving application.
Transmission Control Protocol (TCP) :It is a connection-oriented protocol that is used for the reliable transfer of data from one process to another process. It takes the help of the Port numbers for transmission. It uses flow control and error control mechanisms at the transport level. There are three phases in which TCP transmits the data between the sender and receiver which is as follows:
In the early 1970s, Vint Cerf, together with Bob Kahn and their students, developed the Transmission Control Protocol (TCP) and the Internet Protocol (IP), that is, the collection of rules by which computers and computer networks can be connected to form a larger network, with data packets finding their way from any node to any other without having to worry about the networks' physical implementation.
Of course, with Google being one of the companies that collect huge amounts of person-specific information, is that not a threat to privacy in and of itself? Cerf is very insistent that Google's business model does not involve sharing, or selling, person-specific information - on the contrary he argues that, if they were to do that, no-one would use Google any more. I must confess to some skepticism on that count, seeing that Facebook's evolving data use policies apparently have not triggered a massive exodus from that social network, either.
We agree that it should be made similarly clear and simple for everyone to understand and to control what they share online. But do companies really want that? Cerf, rightly, claims that he cannot "speak for [Facebook's] Mark [Zuckerberg, who's] a young kid who has a different view of privacy than many of the rest of us." For Google, he says, that's what Circles in Google+ were/are all about - "may be not totally successfully". Even with Circles, you have no control over what those other people then do with the data you've handed them.
Then there is the question of eavesdropping, by governments or others. For Google specifically, Cerf states his belief that, as Google builds all of its own equipments and software for the data centers, including the internal networks, he does not believe that there is likely to be a back door allowing the NSA or other agencies direct access to Google data. (He does admit that they assemble their equipment using commercially available chips - if the chips should be modified, that might change matters.)
Knowing what he knows now, if he were going back in time, would he include stronger cryptography to protect Internet transmissions? He did, in fact - in 1975, he started working with the NSA to design a secure internet. But the only equipment available to build such a thing, and encrypt the data packet sent back and forth, was classified. The secure publicly available Internet, in what Cerf calls "a sad story", appears to have missed its chance by bad timing. When Cerf's Stanford colleagues Marty Hellman and Whitfield Diffie published public key encryption in 1976 that was what Cerf calls a "speculative mathematical paper." (The British intelligence agency GCHQ had in fact developed the same algorithm some years earlier, but kept it classified.) By the time Cerf and colleagues standardized the Internet in 1978, there had not yet been a practical (non-classified) implementation - that, the RSA algorithm, came out just a tad later. [I haven't traced the details of the history, but everything appears to have been really close.]
The UDP (User Datagram Protocol) and the TCP (Transmission Control Protocol) are networking communication protocols for transferring data between two devices. You may be wondering why we're covering UDP and TCP connections in an article about chat protocols. Well, all chat protocols are built on either a UDP or a TCP connection. So, it's important to understand the benefits and drawbacks of each protocol.
UDP's biggest benefit is speed. But that speed is achieved by sending packets (units of data) directly to a device without first establishing a connection. This means that UDP doesn't define the order of packets sent or even check to see if they arrived successfully. UDP is often used for time-sensitive data transmissions such as video playback or DNS lookups.
Unlike a traditional HTTP system in which communication can only be initiated from the client, a WebSocket connection is bidirectional. The WebSocket API is supported by all modern browsers and, just like the HTTP protocol, data is transmitted over a TCP port.
XMPP is a protocol for transmitting XML data (Extensible Markup Language) over a network. By streamlining the push mechanism between clients, it enables a real-time messaging experience. XMPP focuses on delivering a network of connected devices that are capable of communicating via their own trusted servers.
The most common use case for MQTT is to automate and communicate IoT devices for a smart home. For example, you can send data from a motion sensor to your mobile device which then triggers your garage door to close. Or you can send data from a dusk to dawn sensor to a Raspberry Pi to trigger your front porch lights to turn on.
This protocol is secure, multichannel, portable, and very efficient. It offers encryption via SASL or TSL and uses the TCP protocol for data transmission. AMQP works in a very similar manner to the MQTT protocol we discussed earlier.
The goal of RCS is to create a richer, more interactive text messaging experience for users. One of its biggest selling points is that it allows for multiple data types including pictures, videos, PDF files, location data, and even Microsoft Word documents. It can also allow customers to complete entire transactions within the messaging app. With RCS one can easily imagine a future in which you can buy, sell, and transfer digital goods right in your messaging app. 2ff7e9595c
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