I am working on tcp socket project.
This is built with node js.
Now I am trying to send data to express so web client(html) can know if new tcp socket signal is arrived or not.
TCP socket signal comes from android.
Please help me how can I detect if new tcp socket signal is arrived in web client panel.
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Im trying to write a server client program, where client sends request through UDP socket to a server, then server responds back to a client through TCP socket.
My question is, how can server establish a TCP connection back to a client after getting the request through UDP?
I'll add code parts on Monday, but I more interested in pseudocode for that. Does that mean that the client should listen on tcp port after sending udp request? So confused
Ive build a local multiplayer game (multiplayer over wlan network). Now, I want to add an online multiplayer feature..
Currently, the network communications consist mostly of "signals" (tcp/udp packets sent from game-host peer to the game-client peers). I would like to use this mostly signal based communication for my online multiplayer (because of performance and efficiency ), too . But, since the host peer is now replaced by a server there will be a lot problems with sending signals (NAT, firewall,...).
So is there good solution to implement these signals?
regards
there will be a lot problems with sending signals (NAT, firewall,...)_
What problems exactly?
Normally, the clients establish a TCP connection to the server and the server uses this TCP connection to communicate with the clients.
For UDP-based communication the clients use Internet Gateway Device Protocol to forward ports on the router, so that the server can send UDP datagrams to the clients.
Assuming your server is in public internet, not behind any NAT. All the clients must initiate the connection. Otherwise the server can't know clients credential and can't connect. As the server has no NAT it will accept connection from client. And this connection client must keep alive. So when server needs to send some data there should be no problem.
This will work for both UDP and TCP.
I have around 20 clients communicating together with a central server in the same LAN. The clients can make transaction simultaneously with the server. The server forward each transaction to external appliance in the network. Sometimes it works, sometimes my application shows a "time out" message in a client screen (randomly)
I mirrored all traffic and found TCP Retransmission after TCP Reset packets for the first TCP Sequence. I immediately thought about packet loss but all my cables/NIC are fine, and I do not see DUP ACK in the capture.
It seems that RST packets may have different significations.
What causes those TCP Reset?
Where should I focus my investigation: network or application design ?
I would appreciate any help. Thanks in advance.
Judging by the capture, I assume your central server is 137.56.64.31. What's happening is the clients are initiating a connection to the server with a SYN packet and the server responds with a RST. This is typical if the server has no application listening on that particular port e.g. the webserver application isn't running and a client tries to connect to port 80.
The clients are all connecting to different ports on the server, which is unusual for an central server, but not unheard of. The destination ports the clients are connecting to on the server are: 11007, 11012, 11014, 11108, and 11115. Is that normal for the application? If not, the clients should be connecting to whatever port the application server is listening on.
The reason for the retransmits is that instead of giving up on the connection upon receiving a RST from the server, the client tries to initiate the connection again so Wireshark considers it a retransmission.
You have two application that need to exchange information among them in a local area network. The first application uses TCP for communication while the second uses UDP. Can we link both applications directly? If your answer is no, explain how we can link them?
(from a homework assignment)
I think the answer is no, we need to use some translator or middleware between them. But what?
As you figured out, you can't simply combine 2 types of connections into one.
TCP is a state-full connection, which requires two computers to establish the connection,
opposing to UDP which is stateless/connectionless connection that requires just one computer, send and forget style.
If you want them to communicate with each other, you must have a middle-ware.
The TCP application should have a TCP Client and TCP Server
The Middle-ware should have a TCP Server that will listen to the TCP application's client and establish connection and a TCP Client that will establish connection with the TCP application's server.
Now the middle-ware can fully communicate with the TCP Application.
In order to do so with the UDP Application, you should listen to UDP at a certain port in order to listen to incoming data from the UDP Application, and send to it over UDP to the UDP Applicaiton (the UDP Application need to listen on that port)
How to use URLRequest to send data to TCP socket in Flash, Actionscript?
So I have TCP server which is listening to some port and on every connection is sending sounds MP3 data to requestor
I've done URLRequest and Sound class plays my sound.
How to send data to that socket not opening new socket connection (using URLRequest or something )
URLRequest only works with the http protocol. So the "TCP Server" you have running must communicate using the http protocol. If does, you should be able to write the address as http://www.mydomain.com:8080 where 8080 would be the port you server is listening on.
If your sever is using another protocol, you have to use the Socket class (or the XmlSocket class).
Also be sure to check the security details.