It is possible that two different MIDlets try to reserve the same sip identity for incoming SIP messages. In this case, the basic principle is that the first MIDlet that reserves the MIME type gets to keep it.
If the reservation is done in the JAD file, when the second MIDlet is installed, the user is notified that the MIDlet requests to use sip identity conflicts with another MIDlet. If the conflict is not resolved (e.g. by deleting the other MIDlet), the new MIDlet will not be installed and an error is indicated.
Dynamic reservations using the PushRegistry API
use the same principle and Connector.open() throws IOException when
the second application tries to open SipConnectionNotifier with
a sip identity that is already reserved by some other application.