Telserv Manual
Telserv Manual—427174-009
10-1
10 Modes of Operation
Several modes of communication are used between:
An application on the NonStop system and the Telserv process.
The Telserv process and the client software, including any TELNET client software
you write.
Figure 10-1 shows the relationship among a client, the Telserv process, and a service
application
Conversation Mode and Block Mode
The HP NonStop Kernel defines two modes of operation: conversation mode and block
mode. Conversation mode configures a conversational terminal service and initiates
the session in conversation mode. This is the default service type. Telserv allows the
use of a type-ahead feature while in conversation mode. Telserv echoes each
character, even if the application has not posted a read request. Because of the type-
ahead feature, Telserv might echo the service name or window name sent by the user
or client program even before the Telserv process sends its own banner. (Note that
type ahead is not provided by Termprocess/ATP6100.)
Block mode configures a 6530 terminal-type block-mode service and initiates the
session in block mode. The application may change the mode by using the file-system
SETMODE procedure. Client software is included in terminal emulators from other
vendors, such as Sun Microsystems. This software can run in block mode or
conversation mode. You can also write your own client program that runs in both
modes. The TELNET client supplied by HP runs in NVT mode and does not support
6530 terminal types.
For information about SETMODE procedures, see the Guardian Procedure Calls
Reference Manual.
If Telserv sets the 653X emulation mode, which includes block mode, the capability to
switch back and forth between block mode and conversation mode is available. The
Note. The term application refers to any service application that you write and that the
interactive user can select, as well as to such HP NonStop utilities such as TACL, FUP,
and INSPECT.
Figure 10-1. Client Software, the Telserv Process, and a Service Application
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Client Software
NonStop Telserv
Service Application