Type              (TCT) 

DESCRIPTION
"Type" indicates the type of connection to a Sun MTP system rather than an 
actual device "Type". All connections to Sun MTP comprise some form of 3270 
communication. Each "Type" of connection is handled by a context-specific 
terminal handler process or Application Programmatic Interface (API). Therefore,
"Type" indicates the process type used to handle a particular terminal 
connection.


VALUES
The "Type" may be one of the following values:  3270, EPI, Free, Local, Remote, 
TN3270, TR, or Unknown (if the "Type" is truly not known by Sun MTPScan). The value
may have a '*' prefix if there is something wrong with the entry. For example,
all items of unknown "Type" show the following value: '*Unknown'.


INTERPRETATION
3270    - Both real 3270 terminals and 3270 emulators connect to a Sun MTP system
          through an XPUx Server. On UNIX platforms except for NCR systems, a 
          unikixb client process handles a terminal connection. A single unikixi 
          server process coordinates multiple unikixb clients. The unikixi and 
          unikixb processes are not required to run on the same "Host" as Sun MTP.
          However, each remote node requires a unikixi coordinator. An NCR with 
          a Comten interface collapses the functionality of unikixb and unikixi
          into a single process called unikixc, one for many terminals. All of
          these processes communicate with Sun MTP via operating system sockets 
          over port 2000 (unless using the -s option to unikixmain). The Trin 
          Server, unikixtrin, must be running to initiate contact. To run this 
          Server, initiate Sun MTP with the KIXHOST environment variable set to 
          the name of the machine that hosts the Sun MTP region.

Free    - This field is marked 'Free' for unused Sun MTP TCT slots. 

EPI     - An EPI connection is a process running on the same host as Sun MTP that
          uses the standard External Presentation Interface (EPI) API to 
          communicate with a Sun MTP system. In this case, there is not a Sun MTP
          provided terminal handler; the application program is its own terminal
          handler.

Local   - A local terminal handler is a 3270 emulator, unikixl, that
          runs on the same "Host" as the Sun MTP system. The unikixl client 
          process can handle both dumb terminals and xterms in the X Window 
          System environment. 

Remote  - A remote terminal handler is a 3270 emulator, unikixs, that uses 
          operating system sockets to communicate across the network with Sun MTP 
          server processes. The remote terminal handler requires unikixtrin 
          running on the KIXHOST. Like unikixl, unikixs handles both dumb 
          terminals and xterms. A user may run unikixs locally and incur the 
          overhead of using the socket interface. Sun MTPScan points this case out 
          with a value of '*Remote'.

TN3270  - TN3270 refers to a Telnet 3270 client. Sun MTP provides a TN3270 Server
          called unikixtn that listens for TN3270 requests. When it receives a 
          request for a connection, the Server spawns a copy of itself to handle
          a particular connection. The unikixtn Server uses a different port 
          than unikixtrin.

TR      - TR refers to a Transaction Route. This is a special case of the 3270
          "Type" because the connection terminal is still a 3270 device. 
          However, the real definition of the terminal resides on the remote 
          system. A TR entry is actually a surrogate entry in the Sun MTP TCT.
          
Unknown - Sun MTPScan shows this value only if it cannot determine the "Type" of
          connection. This value more likely indicates an internal logic error 
          than an actual unknown type of terminal.



CONCLUSIONS
The "Type" field provides the context to give meaning to the rest of the columns
in a TCT Screen entry. Because the TCT Screen displays a variety of connections,
the columns often have multiple meanings depending on the "Type". Furthermore, 
the "Type", together with "Model", "Host", "Device Name", and "LU Name" 
fields, help identify exactly where a connection originates.
