I have never seen that limitation in the Spec, but I could be wrong. But basically for any connection in J2ME, you always want to make sure that you aren't trying to bring over the world. Think about how small the device is, its available memory and what people use phones for. You wouldn't want any Phone App hogging the entire phone for a service that takes forever to occur, and stops calls from coming in. That would be why you would want to limit the amount of stuff that gets tranferred through COnnections.