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Questions tagged [udp]

UDP stands for User Datagram Protocol. With UDP applications can send messages (datagrams) to other hosts on a network without requiring prior communications to set up special transmission channels or data paths.

Because UDP doesn't rely on handshaking to guarantee that packets arrive and in order it can be seen as an unreliable protocol, but for real time systems where acting on the data immediately is the most important consideration not having to wait for delayed packets is a distinct advantage.

UDP is just one communications protocol on the web. Others include:

  • Transmission Control Protocol (TCP)
  • Internet Control Message Protocol (ICMP)
  • Hypertext Transfer Protocol (HTTP)
  • Post Office Protocol (POP3)
  • File Transfer Protocol (FTP)
  • Internet Message Access Protocol (IMAP)

UDP on Wikipedia

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How does udp work when links en route have different speeds?

My understanding of UDP is that it is a best effort protocol. The data is simply sent and may or may not get there. If I am sending data from A to B using UDP over the Internet and the first link runs at 100Mbps and the last at 10Mbps, why don't I…
Simd
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Multicast and duplicate IP addresses

I've developed a Multicast UDP client/server application, which allows a user to remotely change the network configuration of devices belonging to the same multicast group. But what if a device was assigned the same IP address as another device…
H_squared
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Is ARP Connection oriented or connectionless?

Is ARP Connection oriented or connectionless? It uses TCP, but does that consider it connection oriented?
Rick
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TCP/UDP Small Package Size optimization

I currently have the problem, that when a LOT of RTP streams (>800) go to one server the max. speed is onlynabout 70-80 Mbit (on a Gigabit LAN - all Hardware components are Gigabit components) 130 byte payload - with large payload everything is…
pinas
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Set udp packet size limit

I have a CentOS server with a JAVA application that receive UDP data packets, it works all OK until the packet is bigger than 584 bytes, I read something about and seems to be a limit of UDP protocol. My bigger packet is 631 bytes length(payload) I…
E_Blue
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How to handle an abuse complaint?

I have just received an abuse complaint from my hosting service: [2014-04-04 03:30:23 CET] [Timestamp:1396575024] [11717182.634230] Firewall: UDP_IN Blocked IN=eth0 OUT= SRC=My IP DST=128.204.203.251 LEN=70 TOS=0x00 PREC=0x00 TTL=118 ID=6181…
kleinohad
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Segments/Processes running on same UDP socket

Suppose a process in Host C has a UDP socket with port number 12345. Suppose both Host A and Host B each sends a UDP segment to Host C with destination port number 12345. Will both of these segments be directed to the same socket at Host C? Why? I…
Hi There
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Range of Normal Usage for Domain Controller's LDAP Ping

I'm a security research studying CLDAP as a vector for UDP reflection attacks, a from of Denial of Service. I'm not a MS Server expert, so I want to sure up my understanding of the context of the CLDAP service. The CLDAP service is a UDP version of…
chad
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What are TCP Port 5445 and UDP Port 3935 used for on Windows Server 2016?

I'm facing a dilemma, I built 2 physical servers and for some reason for all the IP addresses assigned to that server it's listening on Port 5445 (TCP) and also 3935 (UDP). Applying the same configuration but in VMWARE, it doesn't listen on these…
Henry
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Why I can only send 3 row via netcat on UDP port?

I am new to this command I am sending a file data on UDP 9415 port . --> I have file which has 1000 rows --> I am firing here IP is my destination IP cat test1 | netcat -u 172.x.x.x 9514 --> Now on destination i have syslog-ng which recieves data…
user3332404
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Does UDP includes of source address?

Both UDP and TCP does not include source address, but how does it say UDP IP spoofing is easier than TCP? For example, the following webpage also says about UDP vulnerability. "Unlike TCP, UDP does not have a mechanism for verifying a packet…
Jaeh
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What does the following UDP connection mean?

What does the following entry mean? Is that mean someone has connected to the server from this IP or somthing else? Nov 23 15:33:54 www-prod-2 snmpd[1573]: Connection from UDP: [66.151.147.194]:47011->[xxx.xxx.xxx.xxx]:161
1Bladesforhire
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NAT UDP port switching?

I've read about the Quake 3 networking code that they had to deal with a situation where some older NATs would randomly switch client ports. How common is this issue these days? Is it worth handling when implementing a game network protocol? In…
Nuoji
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Two-way UDP on varying-IP networks

I've heard that on some corporate networks, outbound traffic from the same user can hop around different "from" IPs. Does that break two-way UDP, or do the networks only act that way for TCP? If it does break two-way UDP, is there a common way…
Abscissa
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I have no access to router and portforward and i need to run a webserver

I got some PCs in some different locations with different ISPs and networks with dynamic ip addresses and I have a dynamic dns server that can records new IPs. but there is a problem. ISPs blocked all user to buy static ip and do portforward and…
Reza Azimi
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