Android Question UDPSocket

[peggjones]

I am trying to use UDPSocket. How do I find out which port number to use?

I'm sure this is a daft question to many but I am completely new to any form of networking.

Many Thanks

 

[Erel]

Do you want to listen to incoming data? You can choose any port between 1024 to 65535. You will need to set the same port in the app that sends the data.

 

[peggjones]

Could you help me further please?

I'm playing with your UDPSocket example. I've set the IP correctly but the message never seems to be received. Any ideas why?
.

 

[Erel]

There isn't enough information here.

Are you sending from the device to the desktop?

 

[peggjones]

There isn't enough information here.

Are you sending from the device to the desktop?

No from one tablet to another.

Sorry about lack of info. I know so little I don't know what is relevant. What I have done is as follows -

Copied your example.

Changed line 22 so it has the IP of one of the tablets.

Compiled the programme to both tablets.

Run the programme on both tablets.

I expected the receiving tablet to display "message received".

Many thanks, I do appreciate how difficult it is to understand someone who doesn't really understand what they're talking about!!

 

[Erel]

Which example are you referring to?

Have you set the ports correctly?

 

[peggjones]

Which example are you referring to?

Have you set the ports correctly?

The code I am using is

Sub Process_Globals
Dim UDPSocket1 As UDPSocket
End Sub

Sub Globals
End Sub

Sub Activity_Create(FirstTime As Boolean)
If FirstTime Then
UDPSocket1.Initialize("UDP", 0, 5000)
End If
Dim Packet As UDPPacket
Dim data() As Byte
data = "Hello from Android".GetBytes("UTF8")
Packet.Initialize(data, "192.168.1.96", 5000)
UDPSocket1.Send(Packet)
End Sub

Sub UDP_PacketArrived (Packet As UDPPacket)
Dim msg As String
msg = BytesToString(Packet.Data, Packet.Offset, Packet.Length,"UTF8")
Msgbox("Message received: " & msg, "")
End Sub

I don't understand how the packetarrived routine knows which port it's listening on.

As far as I can see the packet is sent but never received.

 

[Erel]

It should be:

UDPSocket1.Initialize("UDP", 5000, 8192)

 

[peggjones]

Excellent that worked thanks.

Can I ask, how did you know the buffer size needed to be 8192?

 

[Erel]

The problem was not with the buffer size. You set the port to 0 instead of 5000.

You can set the buffer size to a different value based on your packets size.