You might need to allow permission in manifest file to enable ur code to create server socket.
<uses-permission android:name="android.permission.INTERNET"></uses-permission> I am not very sure but this thing worked in my case when i was trying to create a UDP socket. enjoy Pankaj anad On Sat, Mar 13, 2010 at 7:07 AM, Larry <lar...@gmail.com> wrote: > I have tried many tests on how to create a UDP server on android > phone. > > - Devices I was testing: > > PC (has static public IP over Internet. has a UDP server running) > GPhone (it is real phone, not emulator. runs in Tmobile 3G network) > > - Send a UDP packet from GPhone to PC: > > [On GPhone:] > // create a sender socket > DatagramSocket udpClientSocket= new DatagramSocket(); > // send data > udpClientSocket.send(packet); > > [On PC:] > // create a listener socket > DatagramSocket udpServerSocket = new DatagramSocket(SERVER_PORT); > // receive data > udpServerSocket.receive(packet); > > - Send a UDP packet from PC to GPhone > > After a whole day testing on this problem, I can only find this > solution: > > [On PC:] > // get the client's address and port > address = packet.getAddress(); > port = packet.getPort(); > // create packet to send to client > packet = new DatagramPacket(....address, port); > // use the server socket to send a packet > udpServerSocket.send(packet); > > [On GPhone:] > // use the sender socket to receive data > udpClientSocket.receive(packet); > > With these codes, the client can actually receive packet from server. > However, there are 2 problems: > > 1. YOU HAVE TO USE THE SERVER SOCKET TO SEND > > If we change the PC code to: > .....(same stuff) > // create a new socket to send data > DatagramSocket anotherSocket = new DatagramSocket(); > anotherSocket.send(packet); > > The phone will never receive the packet. > > 2. YOU CANNOT ESTABLISH A UDP SERVER ON GPHONE > > If we want to have a UDP server on GPhone just like we have a server > on PC. So that GPhone can talk to a server on PC and PC can talk to > another server on GPhone, using DatagramSocket udpGPhoneServerSocket = > new DatagramSocket(GPHONE_SERVER_PORT) DOES NOT WORK. > > I have tried to send a UDP packet from PC to the phone. I tried all > kinds of ports, addresses, etc. No, it doesn't work. > > * * * * * * * * * * * * * * * * * * * * * * * * > > OK. Now in my android app, I have over 100 clients (GPhone) > communicating to the server (PC) at same time. For performance > concern, I want to create one UDP server socket on PC *ONLY* for > receiving. Then I create one UDP sending socket per connection on the > server to send packets back to the phone. Based on my test, since > establishing a UDP server socket on GPhone is not working. The only > option left for me is to use the only UDP server socket for both > receiving and sending. > > My questions are: > > 1. Am I wrong? (Does any1 have a successful design so that you can > send a packet from PC to GPhone without reusing the server socket?) > 2. If I am correct, is it T-mobile blocking all UDPs? > 3. If I use the *ONLY* server socket for both sending and receiving to > handle 100+ connections with real-time data exchanging at same time, > does it have a poor performance? Any better solutions? > > Any comments are appreciated! > > -- > You received this message because you are subscribed to the Google > Groups "Android Developers" group. > To post to this group, send email to android-developers@googlegroups.com > To unsubscribe from this group, send email to > android-developers+unsubscr...@googlegroups.com<android-developers%2bunsubscr...@googlegroups.com> > For more options, visit this group at > http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
