multicast | 易学教程

Reliable Multicast over local network

阅读更多关于 Reliable Multicast over local network

问题 I am implementing a messaging system using C++ and Qt. After much thought, I have determined that multicasting or a multicast-style technique will work best to solve my problem. However, I have learned about UDP's unreliability and believe it to be unacceptable. My requirements are as follows: Messages are to be sent in a binary serialized form. From any given node on the network, I must be able to send messages to the other nodes. Message delivery must be insured. I have heard of OpenPGM and

How to minimize UDP packet loss

阅读更多关于 How to minimize UDP packet loss

问题 I am receiving ~3000 UDP packets per second, each of them having a size of ~200bytes. I wrote a java application which listens to those UDP packets and just writes the data to a file. Then the server sends 15000 messages with previously specified rate. After writing to the file it contains only ~3500 messages. Using wireshark I confirmed that all 15000 messages were received by my network interface. After that I tried changing the buffer size of the socket (which was initially 8496bytes):

How to send multicast messages and reuse a port in Erlang?

阅读更多关于 How to send multicast messages and reuse a port in Erlang?

问题 I have gotten a good start on my program, my first REAL Erlang program. I have it listening for messages, reading them and parsing them. I also have it sending them. The one little thing that is bothering me is I can't SEND on Port 5353, I have tried everything. All the other applications on my machine can listen AND send on port 5353, SubEthaEdit, iTunes, iChat. The solution MUST broadcast send on port 5353 and here is why. " If the source UDP port in a received Multicast DNS Query is not

MultiCast Messages to multiple clients on the same machine

阅读更多关于 MultiCast Messages to multiple clients on the same machine

问题 Im trying to write a server/service that broadcasts a message on the lan ever second or so, Kind of like a service discovery. The message needs to be received by multiple client programs that could be on the same machine or different machines. But there could be more than one program on each machine running at the same time. Im using delphi7, with indy 9.0.18 where im stuck is if i should be using UDP(TIdUDPClient/Server) or IP MultiCast (TIdIPMCastClient/Server) or if its even possible...

Creating a class for an interface at runtime, in C#

阅读更多关于 Creating a class for an interface at runtime, in C#

问题 I'm looking at taking a set of objects, let's say there's 3 objects alive at the moment, which all implement a common interface, and then wrap those objects inside a fourth object, also implementing the same interface. The fourth object's implementations of methods and properties would simply call the relevant bits on those 3 underlying objects. I know that there will be cases here where it won't make sense to do that, but this is for a service multicast architecture so there's already a good

In order for Udp multicast to work, router must support it?

阅读更多关于 In order for Udp multicast to work, router must support it?

I am wondering for the udp multicast to work, router must support it? Multicast is based on dynamically generated trees that can (theoretically) span the entire internet. These multicast trees are based on two protocols: IGMP : Internet Group Management Protocol. Used by receivers and users like me and you. PIM : Protocol Independent Multicast. Used by routers to replicate and reroute the packets accordingly. The client needs to be IGMP -compatible, and the routers need to be PIM -compatible. To be precise, you will need a multicast router if you want the traffic to traverse different subnets.

How to receive Multicast UDP?

阅读更多关于 How to receive Multicast UDP?

I'm using GCDAsyncUdpSocket and i can send either Multicast or normal UDP packets. I'm receiving normal packets with no problem but I cant receive Multicast packets from another iOS device. To receive I use: - (void)udpSocket:(GCDAsyncUdpSocket *)sock didReceiveData:(NSData *)data fromAddress: (NSData *)address withFilterContext:(id)filterContext { NSString *msg = [[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] autorelease]; NSString *host = nil; uint16_t port = 0; [GCDAsyncUdpSocket getHost:&host port:&port fromAddress:address]; if (msg) { NSLog(@"Message = %@, Adress = %@

How can I diagnose our java IP multicast application?

阅读更多关于 How can I diagnose our java IP multicast application?

问题 For some reason, every multicast example I run (the computer runs OpenSUSE Linux) will work. The clients all just sit silently. How do I figure out why the multicast is being blocked/ignored? Some of the examples: EXAMPLE 1 http://www.roseindia.net/java/example/java/net/udp/UDPMulticastServer.java Example 2 http://docs.oracle.com/javase/tutorial/networking/datagrams/broadcasting.html (uses these files:) http://docs.oracle.com/javase/tutorial/networking/datagrams/examples/MulticastServer.java

Multicast in java

阅读更多关于 Multicast in java

I am trying to write a simple multicast trial. I used a standard code (sender and reciever). I tried a few different standard pieces of code. it appears that the receiving code is stuck on receive (as if it's not receving anything). receive side: byte[] b = new byte[3]; DatagramPacket dgram = new DatagramPacket(b, b.length); MulticastSocket socket = new MulticastSocket(4545); // must bind receive side socket.joinGroup(InetAddress.getByName("226.100.100.125")); while(true) { socket.receive(dgram); // blocks until a datagram is received System.err.println("Received " + dgram.getLength() + "

Why are (UDP multicast) packets not being received?

阅读更多关于 Why are (UDP multicast) packets not being received?

问题 So, I've been trying to figure out exactly why this isn't working but I haven't a clue. I've managed to send packets from the iPhone and receive them on my Mac. And according to tcpdump my mac is correctly sending the packets. Additionally, if I run this in the simulator it works fine. This leads me to believe that it's a network problem, but I have no idea what that could be, so I was hoping(!) that it's something below. CFSocketContext socketContext = {0, self, NULL, NULL, NULL};