A logical unit is a named access point into an SNA network. The SNA
   LU Services LU entity defines one logical unit that is owned and
   managed by the Peer Server.  Each logical unit has a corresponding
   SSCP-LU session which is also owned and managed by the entity. An LU
   can participate in one or more LU-LU sessions, each of which is
   supported by a corresponding Session subentity