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.

learn more… | top users | synonyms

0
votes
2answers
30 views

What does a network packet consists of?

I know basic networking but I am not very good at it. Now I am calculating how many packets will be lost if I use UDP over IPv4. I can assume that the protocol overhead for data sent via UDP over IPv4 ...
1
vote
1answer
29 views

14 bytes preceeding the UDP packet, what is their purpose? Linux

I am analysing packets being sent from an MT4000 telemetry device. I have set up a listener in the terminal(Linux) and set to display the packets being received in hex. So far the packet incoming ...
0
votes
0answers
47 views

Streaming screen over LAN with VLC using RTP

I am trying to stream the screen (video and audio) from a Windows PC to a Linux one (Raspberry Pi), using VLC. I have tried emitting the screen through RTP (I want to do unicast), and then in the ...
0
votes
0answers
39 views

udp client sending ICMP “port unreachable” when receiveing messages from the server

(Note: I moved this question from StackOverflow, because it's to be considered off-topic there, better fits here, and still unsolved) I have a udp client using luasocket, basically doing this (with a ...
-2
votes
1answer
40 views

Public wifi on public bus blocks all udp packets [closed]

Our public bus service gives us free WiFi but all UDP packets are blocked because I couldn't play online games that uses the udp protocol or make voip calls on my android phone. I ran a test on the ...
-1
votes
2answers
49 views

Is there a simple audio player that can be remote controlled with UDP or TCP commands? [closed]

Is there a simple audio player that can be remote controlled with UDP or TCP commands? The control needed is very simple: Stop Play Pause Volume up Volume down Next Track Previous Track
1
vote
0answers
37 views

Is it possible to edit TCP and UDP packets?

Is it possible to edit the UDP and TCP packets a program sends? For example, we have a program that sends some information to its server. But we don't want to send some information that might be ...
0
votes
0answers
53 views

UDP port binding to loopback interface

I've been trying to play a video game in multiplayer, but after trying a lot of time, I begun to realize there was some problem with my loopback interface (Windows 7) I have UPnP activated in my ...
0
votes
0answers
44 views

How to sync two looping videos with mplayer and upd?

I am trying to sync two instances of mplayer with -upd-master and -udp-slave, and notice that the slave staggers for about a second when the master begins the loop anew. I am running debian 7.1 with ...
1
vote
1answer
57 views

TCP vs UDP. Sending data on a closed port

I try to understand differences between TCP and UDP packet on the error-checking. I know that UDP packets are connectionless and doesn't care that the packet will arrive the destination safely. And ...
4
votes
1answer
422 views

For what does ssh use UDP?

Wile doing research I noticed that SSH both uses TCP and UDP. I completely understand the use of TCP, but UDP seems a bit strange. Why would I use an "unreliable" transport protocol with minimal ...
0
votes
3answers
57 views

Changing the ports a program uses

This question might not even make sense. I have a very limited understanding of how networking protocols work. My phrasing of these questions might be very poor. My school has a firewall enabled. ...
0
votes
2answers
160 views

UDP Flood to Host in the firewall logs

When the router's firewall logs shows as follows UDP Flood to Host PRIVATE_LAN_CLIENT_IP, PORT ->> EXTERNAL_PUBLIC_IP, PORT (from WAN Outbound). Will those packets be routed to the private lan ...
0
votes
0answers
38 views

How to use netperf on specific NIC port?

I have two servers, SERVER and CLIENT and each server has its own onboard 1 GbE ports, and its own NIC with a 10 GbE port. SERVER and CLIENT are interconnected on both a 1 GbE switch (administrative ...
4
votes
3answers
919 views

How to force a process transmit over UDP instead of TCP?

I 'm running an ffserver process on a Linux machine, in order to achieve video streaming via ffmpeg. However, there is a delay on video streaming. On ffserver configuration file I define Port 8090. ...
0
votes
1answer
54 views

DNS Resolver for Windows over TCP

I know that DNS uses UDP with Port 53 for DNS queries. However, at my place sometimes UDP requests are blocked and DNS fails. I know that there is protocol for DNS over TCP and many public DNS servers ...
0
votes
0answers
30 views

UDP causing problems with other connections

I have implemented a file transfer program on Windows 64-bit platform using winsock API. I am using a 1Gbps connection. When I transfer files using TCP protocol, I am getting only 320 Mbps. when I ...
0
votes
0answers
24 views

UDP packet priorization simple howto

Is there a simple straightforward way to prioritize all UDP packets incoming on a specific interface? I have a UDP listener that receives information from external GPS devices through UDP, and when ...
0
votes
2answers
77 views

Can using UDP and OpenVPN lead to file corruption?

I know with TCP that it always checks your files to ensure nothing got fragmented or lost or destroyed. So if I use UDP for OpenVPN to download files or access an internal network, does that mean I ...
0
votes
2answers
537 views

OpenVPN client behind corporate firewall

I cannot connect from the corporate network at work to my OpenVPN server. However, with client and server settings untouched, connecting from other networks works. I can only assume that this is due ...
0
votes
2answers
135 views

UDP communication through proxy

I have following scenario: PC B must be capable of full TCP/UPD connectivity, so I'm testing scenario with typical FPS game. ProxyCap is proxifier software, that can connect to outside world ...
4
votes
1answer
1k views

WiFi UDP unicast vs. multicast speed

From what I have gathered UDP multicast / broadcast over WiFi will not yield the speed as one would have thought. What about UDP unicast over WiFi? Can anyone confirm that the latter will have a ...
-1
votes
1answer
30 views

How does an ADSL modem tell which local client to associate with each response from a server?

Does an ADSL modem generate a random string for each request I make and when response comes it directs it to my computer (but not to my phone)?
0
votes
0answers
177 views

Windows 8.1 cannot block UDP connection?

I installed a BT software, which requires both TCP and UDP inbound connection. But my router is very weak. If the UPD/Tx goes up over 100, the router will die. And Windows does not have a function to ...
0
votes
2answers
2k views

what is type of ICMP packets? TCP or UDP

ping packets is a type of ICMP packets.Is there any relation between ICMP with TCP.In other can we guaranty their arrival in the network I want to know ICMP packets in the network is tcp or udp or ...
0
votes
0answers
13 views

Ping works, TraceRt is intermittent [duplicate]

When contacting any somewhat remote IP outside my ISP's network, their edge router (hop 5 in my case) shows partial failures (perhaps 3-4 out of 5 attempts generate *'s), but PING traffic goes through ...
0
votes
0answers
49 views

How to determine mcast_if of process listening on UDP multicast address?

How to determine mcast_if of process listening on UDP multicast address? I know I can netstat -lnp to show what processes are listening on which addresses, but a process may have a mcast_if ethX. ...
2
votes
1answer
96 views

How to monitor TCP and UDP port changes

I am running software on a server that may be turning off some ports and need to find out what it is. I have the ports I need to check. I just need to find out what is turning them off. How can I ...
2
votes
3answers
265 views

Broadcast address in IPV4

I have a small network with the subnet mask 255.255.255.240 and the IP range is 192.168.2.1 - 192.168.2.12. From 192.168.2.1, I want to broadcast a packet. I don't want this packet to go anywhere ...
0
votes
1answer
148 views

Using and testing UDP data over the internet [duplicate]

I have a GSM modem that sends data via UDP (it appears) I have configured it to send all data to my public IP address over the internet but no data is arriving at my end so I need to troubleshoot. I ...
0
votes
1answer
64 views

Are all internet file downloads using FTP protocol?

I heard, FTP is used to transfer files over a network. Also heard that it uses TCP port 20 and 21. So TCP is connection oriented. We have acknowledgments. If the transmission is lost, we should be ...
2
votes
1answer
701 views

Linux SOCKS5 tunneling not working with udp traffic

I am using the command ssh -N -D 0.0.0.0:1080 localhost which works perfectly fine for my web browser, but when I try and tunnel a UDP traffic application it doesn't work. I thought that socks5 ...
0
votes
0answers
97 views

How to monitor the Remote IP Address to which UDP packets are sent in a particular process?

I am able to do this with NetworkTrafficView or SmartSniff (both from Nirsoft), but on my friends machine (Windows XP), when running this application the internet is just cut off, like the entire ...
0
votes
0answers
173 views

Netcat one-time message

I'm trying to use Netcat to debug a UDP listen server that I'm writing, and I'm surprised by the behaviour: $ echo -n Hello World | nc -v -u -6 localhost 12201 - Connection to localhost 12201 port ...
1
vote
1answer
334 views

“udp relay” via openssh socks proxy

I'm trying to run a UDP based multiplayer game (dota 2) via the following chain dota2 (OS X)-> proxycap -> ssh tunnel -> home machine (OS X) -> internet The home machine is running the ...
1
vote
1answer
367 views

How does a proxy know where to forward the requests to?

When a proxy receives a connection how does the proxy know where to forward the request to? For example in Java we can set a system property for proxy. So we set the IP of the proxy and the request is ...
0
votes
1answer
471 views

Are UDP packets firewall proof?

I have been testing this "bittorent sync" software (a peer to peer application) as an experiment. I decided to block the application using the Windows firewall on the computer that is running the ...
0
votes
1answer
1k views

What range of UDP ports may rtsp use, to configure a firewall?

To allow incoming rtsp streams, I must open incoming TCP port 554. I must also open a range of UDP ports. 6970 through 6999, says http://comments.gmane.org/gmane.comp.security.shorewall/660 . At ...
1
vote
1answer
116 views

Wake-On-LAN and Access Control List with Mac over Internet

I am researching the best way to wake my computer through a firewall over the internet remotely (the computer to be woken is a Mac). Through external research, I have seen that I should be able to ...
0
votes
1answer
1k views

netcat udp address already in use

I am trying get a response from the server by using the command echo 'my message' | nc -l -u 127.0.0.1 2947 But I get nc:Address already in use. for a response. How do find the reason for this ...
0
votes
0answers
125 views

Send data from file to local UDP port

I've got an application, A, that listens on a user-defined UDP port for a specific message that normally comes from another application, B. Application B has a tool that allows recording these ...
1
vote
1answer
813 views

Limit UDP outbound traffic to loopback (localhost) instead of eth0

Atm i'm testing it on Ubuntu Server at VMware Workstation + Windows 7 local host with bridged connection. Later this has to go to live server. I have VLC streaming video file on Ubuntu with cvlc ...
1
vote
1answer
52 views

TCP vs UDP Error-Checking

I've bounced upon two articles that describe in-depth on how TCP and UDP connections work. However there is some kind of inconsistency. Where one article tells me that UDP does no Error-Checking at ...
0
votes
2answers
94 views

Port forwarding beginner

I have been trying to set up port forwarding for the past 48 hours and I can't quite get it. I have used online port scanners to see what ports are open and they are saying none, not even the port I ...
0
votes
1answer
284 views

DNS: can't dig 8.8.8.8 directly

me@ubuntu:# dig @8.8.8.8 google.com ; <<>> DiG 9.9.2-P2 <<>> @8.8.8.8 google.com ; (1 server found) ;; global options: +cmd ;; connection timed out; no servers could be ...
1
vote
0answers
720 views

FFmpeg/avconv and UDP - connect listener after sender?

I'm trying to troubleshoot a port binding issue in avconv/FFmpeg. I have two test commands; one which sends an audio stream over UDP: avconv -i test.wav ...
2
votes
2answers
2k views

How to detect if network is dropping UDP packets?

I'm got a video streaming application that runs fine in my office but fails miserably at the customer location. The symptom is that every couple of seconds, I stop receiving UDP packets for 2 seconds, ...
0
votes
1answer
1k views

vlc part of desktop streaming to <host>:<port>

With VLC, I wish to stream a portion of the desktop and send it to another host on my local area network. The capture seems to work, I see a correct portion of the desktop into the VLC server, but ...
0
votes
2answers
125 views

Is sending syslog events over udp secure?

I'm considering using a service from papertrailapp.com (other similar services are loggly and splunk), where you configure your syslog to echo events to it over udp. It involves adding this entry to ...
0
votes
1answer
77 views

My laptop can't find a device that is connected to a my router but my other laptop can find it

I have this device that uses port 80000 and UDP. It came with a program that communicates with it. However, my laptop (laptop A) can't find that device using the program. So I tested the program to my ...