An "Entity Bean" is a type of Enterprise JavaBean, a server-side Java EE component, that represents persistent data maintained in a database.
Entity Beans have been marked as a candidate for pruning as of Java EE 6[1][2] and are therefore considered a deprecated technology.
Obtaining 1000 entity beans as a single operation would result in 1000 simultaneous internet connections to the RMI back-end [citation needed].
Since TCP/IP only supports 65536 ports you are essentially limited to using 65536 entity beans at a time.
For example, if a client application wanted to monitor the state of 1024 database entries it would take 1024 entity bean references and thus 1024 RMI connections to the EJB server, the EJB server would in turn need to support all 1024 connections from each client application, and would be limited to serving at most 64 client applications at which point all further internet connections would be ignored.