Telserv Manual

Subsystem Control Facility (SCF) for Telserv
Telserv Manual—427174-009
4-13
Object-Name Templates
SU Windows
SU windows support applications that must keep the context of the previous session
when the client reconnects. To configure an SU window, use a null string for the
SERVICENAME attribute of the WINDOW object. For example:
ADD WINDOW #win, SERVICENAME ""
Only one SU window exists for each Telserv process.
Clients can access SU windows only by specifying the window name (for example,
#win). An SU window emulates the behavior of ATP6100-over-dial up-lines in support
of 6530 terminal emulators and 6530 terminals attached to the Ungerman-Bass
terminal server. SU windows differ from static windows in that Telserv does not reject a
connection from a remote client when an SU window is not opened by the application.
Such connections are rejected in the case of a static window.
Whenever TCP/IP reports a fatal error, Telserv returns an file-system error 140
message (FEMODEMERR) for all outstanding requests. However, it keeps its internal
control block open, preserving the content of the previous session. Consequently, the
application can retry the I/O operation without reopening the window. When
applications must maintain security, they should authenticate the remote client before
retrying the I/O operation or repainting the screen.
Summary of Window Types
Table 4-3 summarizes the differences among static, dynamic, and SU windows.
Object-Name Templates
Object-name templates allow you to specify multiple objects by entering a pattern
composed of a single wild-card symbol or of text and one or more wild-card symbols.
With Telserv, you can use the following wild-card symbols in object-name templates:
* Use the asterisk to represent a character string of undefined length. You can use
an asterisk to represent the following:
Table 4-3. Window Types
Static Window Dynamic Window SU Window
SERVICENAME specifi-
cation in SCF ADD com-
mand
Quoted string N/A Null String
Client connects using Service Name TACL, etc. Window Name
File-system error
returned to application
140 66 140
Expected application
recovery action
Re-open the win-
dow and start new
session
Terminate Authenticate client
before restarting
I/O