Telserv Manual

Modes of Operation
Telserv Manual—427174-009
10-2
client software uses option TELOPT_TTYTYPE during negotiation and sends one of
the following strings:
TN6530
TN653X
UB6530
UB653X
In block mode, additional applications are available to the terminal user; for example,
TEDIT on a NonStop S-series server operates in block mode.
Telserv ignores all other terminal-type options requested during negotiation with a
client program.
Line Mode and Character Mode
In character mode, the TELNET client immediately sends each character the user
types to the remote system. In line mode, the text the user types is echoed locally and
sent to the remote host when the terminal user presses the RETURN key (start and
stop bits indicate the beginning and end of the data string). The TELNET client enters
the mode the user specifies only if the remote host is capable of entering that mode.
By default, the mode is CHARACTER.
ASCII Mode and Binary Mode
Telserv supports both ASCII and Binary transfer modes. ASCII is the default mode.
When in ASCII mode, Telserv performs end-of-line processing of incoming and
outgoing data.
Telserv can provide binary data transfer when the client software and the application
on the NonStop system perform the actions described below.
Client Software
The client must initiate TELNET Binary mode for both directions. This action results in
turning off end-of-line processing. However, incoming and outgoing <CR><NULL> and
<CR><LF> remain unchanged.
Note. For the negotiation to succeed, the Telserv process must be in 8-bit mode. By default,
Telserv runs in 8-bit mode.
To set 8-bit mode, the system administrator who starts the process can use the -8 start-up
option, or the application can issue a SETMODE 23 procedure call.
Failure of the SETMODE 23 requires system administrator intervention. The system adminis-
trator must restart Telserv and either explicitly specify -8 for the start-up option or allow the
option to default to 8-bit character mode.
Even when Binary mode is set, both the Telserv process and the client software must escape
IAC so as not to conflict with TELNET commands