Thanks on the link!

The address 255.255.255.3 was just an example.
I have 3 subsystems and (currently) each one of them has just 1 node.

What I really need is:
1. Check if specific component (I know just the component Id) is up somewhere - 255.255.X.255.
2. Send a message to a group of components with the same Id - X.Y.Z.255.

As you wrote, when I send message to X.Y.Z.255, actualy the message arrives to X.Y.255.255.

Thanks for the explanation. That helps a lot!

I think I have a solution for your problem.

First, to address the discovery problem ( 1. ). There is an undocumented experimental function that allows components to ask the node manager to lookup JAUS addresses. The function is: ojCmptLookupAddress(). It takes two parameters. The first is your component's handle, then next is a JAUS Address that you wish to lookup. In this case you would like to lookup 255.255.X.255. If such a component exists in the system, the function will return a value of true, and the JausAddress that you passed in will be modified with the first component that the node manager finds that matches your requirements. So in your case, you should be passed back some address: P.Q.X.R. You can then send messages to P.Q.X.255.

To address the broadcasting problem ( 2. ). I have made a modification to JausOpcUdpInterface.cpp and pushed it to our version33c repository on googlecode. You can use that modified version and it should no longer send: X.Y.Z.255 to X.Y.255.255. Let me know if it works and I'll make the change official. If not, I can back the change out of the repository.

Thanks!
Tom

The good news are that ojCmptLookupAddress() works.
The bad news are about the broadcast...

For the test, I've executed 2 subsystem s1, s2 that each one of them has one node with Id 1.
I've also turn on few components with Id 2 and 3 (so I'll have more than 1 instance).
I wrote a component that run over subsystem s1 that sends the broadcast message.

And the results are:
s1.1.2.255: No component received message.
s2.1.2.255: Works!
s1.1.255.255: Works!
255.255.2.255: Only components with Id 2 on s2 got the message.

My conclusion is that there is some problem when the destination is internal and the component Id is specific.

I don't know why all combination is needed, but it's part of JAUS standart, so I think it should work...


Thanks Tom!

Glad to hear we're making progress. I think I found the solution to the specific component id problem. I committed a change to the version33c repository in file: JausComponentCommunicationManager.cpp

I believe it should fix the problem. Let me know if it works!

It seems to work - thank you on the fast solution!


I went over the different options and I think that now everything works accept for broadcast when the instance Id is fixed:

255.255.255.W: All components receive.
255.Y.255.W: All components receive.
X.Y.255.W: All components on subsystem X receive.
X.255.255.W: All components on subsystem X receive.
255.255.Z.W: No component receives.
255.Y.Z.W: No component receives.
X.255.Z.W: No component receives.