Not able to receive UDP Data

by Scott » Fri, 18 Mar 2011 00:20:03 GMT

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I am trying to receive UDP data sent from server to my android
emulator client. But i am not able to receive the UDP data in my
android client application which is running on emulator.
packet = new DatagramPacket(buf, buf.length);

1) Can you please let me know how to fix it and receive UDP data on
emulator from server application running on some other system.

2) Will i face same problem in receving UDP data if i run my client on
the Android hardware/Android based mobile.

3) Will i face similar problem in receving the TCP based data when
running the application on the Android Emulator.

Kindly pleas guide/help me to get the answers to the above queries.


Re: Not able to receive UDP Data

by Indicator Veritatis » Fri, 18 Mar 2011 08:09:18 GMT

 Step 1: make sure you can receive TCP. Step 2: open the right UDP
ports on your firewall and run Wireshark if you are still not
receiving anything. Debug based on what you see.Step 3: get it working
on a real phone using WiFi on the same local network as your emulator.

If it then fails when you use your phone carrier's data service, the
problem is almost certainly their firewall.


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Re: Re: Not able to receive UDP Data

by Miguel Morales » Fri, 18 Mar 2011 08:20:45 GMT

 I've read people on the internet recommending to use UDP for game networking
on Android.  However, when I was attempting to implement it using my real G1
device on Tmobile.  However, I didn't have any success.  I don't really
recall having tried it on the emulator, but I probably did.
If anyone had any luck implementing a udp server on an Android device, I'd
be interesting to hear how.

~ Jeremiah:9:23-24
Android 2D MMORPG: http ://


Re: Not able to receive UDP Data

by emymrin » Fri, 18 Mar 2011 16:34:43 GMT

 UDP works well on emulators and devices.

DatagramSocket socket = new DatagramSocket(port);
byte[] data = new byte[1000];
DatagramPacket datagram = new DatagramPacket(data, 0, data.length,
null, 0);


Re: Re: Not able to receive UDP Data

by Miguel Morales » Fri, 18 Mar 2011 17:01:39 GMT

 Can you verify this works on a device through a regular carrier signal and
not through wifi?

~ Jeremiah:9:23-24
Android 2D MMORPG: http ://


Re: Not able to receive UDP Data

by Indicator Veritatis » Sat, 19 Mar 2011 09:40:49 GMT

 t worked when I did it with my G2 on T-Mobile. It worked with either
one of WiFi or 4G (the carrier's data).

But I said to debug on WiFi first, since there you have greater
control and transparency: you can run Wireshark and see configuration
on more points in the network. If you root your phone, you can even
run tcpdump on the phone.

On Mar 18, 2:01am, Miguel Morales <> wrote:


Re: Re: Not able to receive UDP Data

by Miguel Morales » Sat, 19 Mar 2011 10:19:04 GMT

 reat, it's been a while since I played with it because I implemented a
reliable and good enough tcp solution. I'll revisit this if necessary to
improve performance, hopefully this helps the OP resolve his problem.
I was worried that some carriers would not allow UDP to phones, I'll still
have to think of the balance between reliability and performance.


On Fri, Mar 18, 2011 at 6:40 PM, Indicator Veritatis <>wrote:

~ Jeremiah:9:23-24
Android 2D MMORPG:


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