Requirement: connection.clientID.duplicate

The client state identified by a client identifier can be in use by only one client at a time. A JMS provider must prevent concurrently executing clients from using it. This prevention may take the form of JMSExceptions thrown when such use is attempted; it may result in the offending client being blocked; or some other solution. A JMS provider must insure that such attempted 'sharing' of an individual client state does not result in messages being lost or doubly processed. TODO - don't handle the blocked scenario

See:

• Section 4.3.2, Client Identifier