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UDP, or User Datagram Protocol is a very simple communication protocol. It is a part of the Transport Layer of the OSI model - the same as the well known TCP.
UDP is very straight forward, containing very few features. There is no hand shaking, no security, no ordering of packets and very little error detection (if any at all).
The structure of a UDP packet is as follows:
Bits 0-15: Source Port Number (optional - leave as all zeros if unused)
Bits 16-31: Destination Port Number
Bits 32-47: The length of the entire UDP datagram (note that the maximum size is 2^16-1)
Bits 48-63: The checksum (optional under IPv4 - leave as all zeros if unused)
Bits 64-??: The actual data.
About the checksum: this is the confusing part about UDP. When a checksum is computed, the UDP software creates a fake header to include in the checksum calculation - but this fake header is not actually transmitted. The structure of this fake header (officially called the "pseudo header") is:
For IPv4:
Bits 0-31: Source IP address (taken from the IP header)
Bits 32-63: Destination IP address (taken from the IP header)
Bits 64-71: Reserved - leave as all zeros
Bits 72-79: Protocol (taken from the IP header)
Bits 80-95: Length (taken from the UDP datagram)
Bits 96-??: The UDP datagram described above.
For IPv6:
Bits 0-127: Source IP address
Bits 128-255: Destination IP Address
Bits 256-287: Length
Bits 288-311: Reserved (leave as all zeros)
Bits 312-319: Next header
Bits 320-???: The UDP datagram described above
NOTES:
-this is only the structure of the UDP packet - and does not include the IP header.
-Since it is possible for the checksum to end up as 0, the standard dictates that a checksum of zero be changed to 0xFFFF in order not to confuse with a checksum field which is disabled. This is true even under IPv6, where the checksum MUST be used. A checksum field value of zero is an error and the datagram should be discarded.
-UDP makes no guarantees that the datagram will arrive, nor does it make any guarantees about the order that the datagram arrives in. If the user wants these features, then these will need to be implemented by the applications using UDP to communicate, or use a different communication protocol such as TCP.
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Explain the format of udp hearder udp message queqe?
. A Explain the overview of UDP messaging.
Why is UDP considered unreliable?
Routers Drop a lot of UDP packets
How do you explain the format of udp hearder and explain the udp message queue?
i want argent answer
What is ntp port number?
UDP port 123. (UDP is a connectionless protocol that sacrifices reliability for speed and bandwidth).
What is an important characteristic of UDP?
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What is the Difference between the TCP and UDP in computer networking?
An important difference is that TCP includes mechanisms for reliable data communication (lost parts of the communication are re-sent), UDP doesn't. TCP is used when such a reliable communication is important. When speed is more important than reliability, UDP is used instead. This is the case with phone or video communication over the Internet.An important difference is that TCP includes mechanisms for reliable data communication (lost parts of the communication are re-sent), UDP doesn't. TCP is used when such a reliable communication is important. When speed is more important than reliability, UDP is used instead. This is the case with phone or video communication over the Internet.An important difference is that TCP includes mechanisms for reliable data communication (lost parts of the communication are re-sent), UDP doesn't. TCP is used when such a reliable communication is important. When speed is more important than reliability, UDP is used instead. This is the case with phone or video communication over the Internet.An important difference is that TCP includes mechanisms for reliable data communication (lost parts of the communication are re-sent), UDP doesn't. TCP is used when such a reliable communication is important. When speed is more important than reliability, UDP is used instead. This is the case with phone or video communication over the Internet.
What is the difference between a DNS port and UDP?
There are a lot of differences between a DNS port and UDP. An example would be DNS is for translation while UDP actually relays the host communication.
How the operating system knows the difference between tcp and udp packet?
The "packets" are actually called "segments" in the case of layer 4 (i.e., TCP or UDP).When creating an IP packet, a host (computer, or other equipment that participates in a communication) adds information to the "protocol" field. This indicates whether the IP packet transports a TCP segment, a UDP segment, or some other kind of information.The "packets" are actually called "segments" in the case of layer 4 (i.e., TCP or UDP).When creating an IP packet, a host (computer, or other equipment that participates in a communication) adds information to the "protocol" field. This indicates whether the IP packet transports a TCP segment, a UDP segment, or some other kind of information.The "packets" are actually called "segments" in the case of layer 4 (i.e., TCP or UDP).When creating an IP packet, a host (computer, or other equipment that participates in a communication) adds information to the "protocol" field. This indicates whether the IP packet transports a TCP segment, a UDP segment, or some other kind of information.The "packets" are actually called "segments" in the case of layer 4 (i.e., TCP or UDP).When creating an IP packet, a host (computer, or other equipment that participates in a communication) adds information to the "protocol" field. This indicates whether the IP packet transports a TCP segment, a UDP segment, or some other kind of information.
Which protocol provides connectionless network service?
In internet protocol suite UDP is the connectionless protocol. There is no initial communication between client and server. UDP will not check whether the transmission was successful.
Which Transport layer protocol does TFTP rely?
TFTP uses UDP - TFTP stands for Trivial FTP, and it is called trivial because it does not check to ensure delivery, it uses UDP which makes a best-effort delivery attempt
What is the difference between TCP and UDP socket?
TCP and UDP are both communication network protocols. TCP protocol in its essence is to guarantee delivery of information, and in the order sent. UDP protocol is lighter, by fact of not checking for the connection to be ready to receive on the other end, not checking if the information getting to the other end is correctly received.
What is fastest udp or tcp?
UDP
What is are pieces of software allowing communication between peripherals called?
I think the word you're looking for is 'drivers'. Drivers are small pieces of program that allow the computer to recognise and 'talk' to peripherals.
Explain the format of udp hearder udp message queqe?
. A Explain the overview of UDP messaging.
What is the layer 4 UDP PDU called?
Datagrams TCP/IP layer 4 PDU's are called segments...
What protocol uses udp?
DNS uses both TCP and UDP, also a lot of online chats use UDP. I think even when you want videos on YouTube UDP is used to deliver video and audio.
Which is one of protocols of transport layer?
The two that are most commonly used are called TCP and UDP.
