Java EE (Java Enterprise Edition) General Discussion

I'm new to JMS. Read through JMS tutorial and ran all examples. I have several fairly simple questions.

1. Does Message consumer and Message producer of a message have to use same ConnectionFactory (Both of them get the connection factory through JNDI lookup).

2. My understanding of message ack is that for message consumer the ack would be sent back to topic/queue. for message producer the ack would be sent back to the sender. Is that correct?

3. If in my client I get two different connection factory cf1 and cf2 and one topic first. Then I create two publisher with the same topic. If I sent two messages through two publishers respectively, do these two messages go to the same topic? If they do, how does subscribers know which message is for it and which one is not. Is it based on how the subscriber is created, ie, which connection factory is used to create the subscriber?

Thanks.