JCA connection problem

Hi.

I have a question about JCA connection pool.

When we made a Function Call to SAP R/3 in Portal, Can Serveral Portal user share JCA Connection ?

Here is MY Scenario.

1. "UserA" login portal and made a Function call to SAP R/3 (Login Method : SAPLOGONTICKET)

2. "UserA" close SAP Connection.

3. "UserB" login portal and made a Function call to SAP R/3 (Login Method : SAPLOGONTICKET)

4. "UserB" close SAP Connection.

5. I checked JCA Pool and they have 2 free connection.

6. I Checked SAP R3 User monitor and I found two login user ID ("UserA","UserB")

Why "UserA" and "UserB" doesn't share one JCA connection in spite of Pooling ?

Anybody know JCA Pooling mechanism ?

Regards, Arnold.