7


TB005  SNA ENVIRONMENTAL BUZZWORDS AND DEFINITIONS
 
                J.D.S. MicroProcessing Technical Bulletin             

Date Written: 08/02/89                   Submitted by: R. SANDE     
    Sequence: 1 of 1                           FileID: 4.TB005      

                                                                        
           SNA ENVIRONMENTAL BUZZWORDS AND DEFINITIONS          
                           
                                                                        
PLU  Primary Logical Unit  Located within the mainframe's application
program. Ex. Condor, an application by Phoenix Software, speaks to the PLU which in turn talks to the SLU's on the HydraSNA.                                                       
                                                                        
SLU  Secondary Logical Units  Are located in the actual cluster       
controller.                                                             
                                                                        
NAU  Network Addressable Unit. Contains the local address of the       
device. NOTE: 00 & 01 are reserved for the physical unit. This is       
a VTAM specific limitation.                                             
                                                                        
                                                                        
==== Physical Unit Types Available ====                                 
                                                                        
PU 1.0 = Intelligent Workstation (Ex. 3770 Workstation)                   
PU 2.0 = Cluster Controller, HydraSNA, 3274, 3174                      
PU 4.0 = Communication Controller (Ex. 37xx)                            
PU 5.0 = Another Mainframe Entity Running VTAM                          
                                                                        
                                                                        
====Logical Unit Types Available ====                                   
                                                                        
LU 1.0 = SCS Printer (SNA Character Stream)                             
LU 2.0 & 2.1 = Display terminals 3277, 3278, 3279                       
LU 3.0 = Printers 328x DSC mode (Data Stream Compatibility)             
LU 4.0 = RJE Station with Multiplexed Printer (Ex. 3770)                
LU 6.2 = Application to Application (Ex. CPU to CPU transactions)       
                                                                        
BIU  Basic Information Unit                                            
PIU  Path Information Unit                                             
                                                                        
TH  Transmit Header (6 bytes)                                          
RH  Request/Response Header (3 bytes)                                  
RU  Request/Response Unit (variable size)                              
LH  Link Header (4 bytes)