udp

问题 I have simple UDPServer class, which is fetching some data, and I can setup what size of each packet do I need. When I set packetSize = 1024 (this property set on Windows desktop application) everything seems work fine, but when it's more, for example 2048, i have weird logs like this: [] udp_validate_cksum_internal [C6:1] udp incorrect IPv4-UDP non-offload checksum 0xf3ff ulen 1506 [] nw_protocol_ipv4_get_input_frames_block_invoke [C6:2] Dropping unused IPv4 extra fragment Appears on iPhone

问题 The remote device is sending live raw PCM audio(no header included) in UDP packets and I need to implement a program in java to receive these packets and play them on the PC live. As I know that raw PCM's attributes are 16bit, mono, sampling rate 24KHz, so I tried to add a wav header to this raw PCM audio and play but the problem is I don't have File size of the audio. I also implemented a program based on this link but it only gives noise in output. I am bound to use UDP and I can get only

问题 I have a linux applications which sends data over UDP protocol. It uses these header files: #include <stdio.h> /* standard C i/o facilities */ #include <stdlib.h> /* needed for atoi() */ #include <unistd.h> /* defines STDIN_FILENO, system calls,etc */ #include <sys/types.h> /* system data type definitions */ #include <sys/socket.h> /* socket specific definitions */ #include <netinet/in.h> /* INET constants and stuff */ #include <arpa/inet.h> /* IP address conversion stuff */ #include <netdb.h

问题 Why does UDP have a length field in the header and TCP does not? I am guessing that the length of the segment in TCP is inferred from the IP header but one should be able to do the same for a UDP datagram 回答1: According to TCP/IP Illustrated Volume 1 , the length field is redundant. That's all Stevens says on the matter. I personally believe it was to make the UDP header length (in bits) divisible by 32 :) 回答2: There is a 96 bit pseudo header conceptually prefixed to the TCP header that

问题 I have the following typical code in C under Linux to get UDP data: sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP); mysock.sin_family = AF_INET; mysock.sin_addr.s_addr = INADDR_ANY; mysock.sin_port = my_port; bind(sock, &mysock, sizeof(mysock); recvfrom(sock, buf, PKTSZ, 0, &client, len); All the above code works, but now I have a need to find out the sender's udp port, is there a structure or system call I can use to retrieve such info when I receive a udp packet ? thanks 回答1: recvfrom(sock

问题 Following on from my previous thread, I seem to be closer to decoding IPFIX data from a Sonicwall firewall using a UDP listener and a BitArray in C#. I now get data in my BitArray but it doesnt make sense - I thought I would see binary in my array but I am getting values very different e.g. 8 - 10 characters some positive and some negative and the Count of the array always varies. Here is the main part of the code I am using to get the bits: byte[] bytes = listener.Receive(ref _myEndPoint);

问题 Following on from my previous thread, I seem to be closer to decoding IPFIX data from a Sonicwall firewall using a UDP listener and a BitArray in C#. I now get data in my BitArray but it doesnt make sense - I thought I would see binary in my array but I am getting values very different e.g. 8 - 10 characters some positive and some negative and the Count of the array always varies. Here is the main part of the code I am using to get the bits: byte[] bytes = listener.Receive(ref _myEndPoint);

问题 I observed a behavior of my python code running in a docker container I don't understand. Maybe someone can explain me the behavior and can me tell the difference between python socket on Ubuntu 18.04 and the docker image python:3.6 If I start my UDP socket at my host the server thread unblock on every received datagram and print the bytes out. That is the behavior I expect. If I start the same code in docker container, there is no unblocking and no output to stdout. If a stop the server with

问题 I observed a behavior of my python code running in a docker container I don't understand. Maybe someone can explain me the behavior and can me tell the difference between python socket on Ubuntu 18.04 and the docker image python:3.6 If I start my UDP socket at my host the server thread unblock on every received datagram and print the bytes out. That is the behavior I expect. If I start the same code in docker container, there is no unblocking and no output to stdout. If a stop the server with

问题 I have an Android app written using the DatagramSocket library, and Python server on my laptop written using the socket library. They both communicate with each other. When the Android phone and laptop are connected to my home internet it works fine. Standard out-of-the-box router setup. However, when I connect the phone and laptop to a mobile hotspot it won't work. I need this functionality for a demonstration in college, as the college wifi doesn't work either. Any suggestions what's