how to receive multicast packet

[electro179]

hello


The multicast receiving doesn't work

I explain my network

My software on my computer sends a message
port = 3693
destination = 239.255.36.93


my code

Sub Activity_Create(FirstTime As Boolean)   
UDPSocketAdn.Initialize("UDPSocket",3693,1000)

Obj1.Target = Obj1.GetContext
   Obj1.Target = Obj1.RunMethod2("getSystemService", "wifi", "java.lang.String")
   Obj1.Target = Obj1.RunMethod2("createMulticastLock", "mylock", "java.lang.String")
   Obj1.RunMethod2("setReferenceCounted", False, "java.lang.boolean") 


   Obj1.RunMethod("acquire")
end sub
Sub UDPSocketArtnetAdn_PacketArrived (Packet As UDPPacket)
   ToastMessageShow("received Multicast",True)

End Sub

and
<uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE"/> in the manifest

How to do to receive a message ?
Have I do a mistake ?
thank to for your help

 

[Vader]

Is the packet going through any routers? Most routers are configured to block UDP traffic.

 

[Vader]

Actually, try this...

Change this line:

UDPSocketAdn.Initialize("UDPSocket",3693,1000)

To this:

UDPSocketAdn.Initialize("UDPSocketArtnetAdn",3693,1000)

 

[electro179]

sorry but I misspelled but my code is correct

Between 2 pc there is no problem I see the message with wireshark


An idea ?

 

[Erel]

Do you see regular UDP packets sent to the device?

 

[electro179]

yes if I send from android a udp packet, I can see on Wireshark.

I receive on android if it's not a multicast packet

 

[electro179]

and the other dircetion, no problem

 

[Erel]

Seems like Android support for multicast packets is not perfect: Programming Mobile: Multicast and Android – A Big Headache

Try to install this application and see whether it works: Testing multicast support on Android devices : Caffeinated Bitstream

 

[electro179]

who has already received a multicast packet ?

I work on android 2.3 (galaxy beam)

this code must be call once time and where ?

   ReflectorADN.Target = ReflectorADN.GetContext
   ReflectorADN.Target = ReflectorADN.RunMethod2("getSystemService", "wifi", "java.lang.String")
   ReflectorADN.Target = ReflectorADN.RunMethod2("createMulticastLock", "mylock", "java.lang.String")
   ReflectorADN.RunMethod2("setReferenceCounted", False, "java.lang.boolean") ' not really necessary but safer

   ' needs <uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE"/>
   ReflectorADN.RunMethod("acquire")

I am blocked in my program. :BangHead:

thank you for you help

 

[Vader]

Why not in Activity_Create ?

Sub Activity_Create(FirstTime As Boolean)
   'Do not forget to load the layout file created with the visual designer. For example:
   'Activity.LoadLayout("Activity1")
   
   If FirstTime Then
      ReflectorADN.Target = ReflectorADN.GetContext
      ReflectorADN.Target = ReflectorADN.RunMethod2("getSystemService", "wifi", "java.lang.String")
      ReflectorADN.Target = ReflectorADN.RunMethod2("createMulticastLock", "mylock", "java.lang.String")
      ReflectorADN.RunMethod2("setReferenceCounted", False, "java.lang.boolean") ' not really necessary but safer
      
      ' needs <uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE"/>
      ReflectorADN.RunMethod("acquire")
   End If

 

[electro179]

Igmp

Hello

I tested the application : multicast test cool and my mobile can receive the multicast packet.

I saw with wireshark that this application send a message IGMP to join the group.
My question is : This protocole is required ? and if yes how to do with b4a

thank you

 

[electro179]

In java, we can do it

MulticastSocket | Android Developers

by using the function

joinGroup(InetAddress groupAddr)

How to do it with b4a to include the java code

 

[Erel]

This is currently not possible. You can write a Java library and use it.

 

[electro179]

I'm going do it

do you think I must rewrite the library "network" or I can write a little program to send a command to join a group =>
- Create socket with library network and an other to join the group. There will be 2 different sockets. No ?

 

[Erel]

It will be difficult to work with the current class as it create a DatagramSocket, not MulticastSocket.

 

[electro179]

ok thank you for your help

I'm going to begin to do a new library

 

[Kevin]

Just curious if this ever went anywhere. I am having the same issue. I need to specify an address {joinGroup(InetAddress groupAddr)}.

 

[klarsys]

Anybody got success here?

I'm not able to receive any messages in Multicast Test Tool even if I run iTunes on my Windows machine or run 'perl send_mdns.pl' without any errors.
Does that mean my device does NOT support multicast messages?

Is there any other way to check?

 

[klarsys]

Anybody got success here?

Never mind. Although test tool did not work, my code for listening to IPort worked.