The Free On-line Dictionary of Computing (30 December 2018):

Upper Layer Protocol

    1. (ULP, or upper-layer protocol)
   Any protocol residing in OSI layers five or above.

   The Internet protocol suite includes many upper layer
   protocols representing a wide variety of applications
   e.g. FTP, NFS, RPC, and SMTP.  These and other network
   applications use the services of TCP/IP and other lower
   layer protocols to provide users with basic network services.

   2. A protocol higher in the OSI reference model than the
   current reference point.  Upper Layer Protocol is often used
   to refer to the next-highest protocol in a particular
   protocol stack.

   (1999-02-17)