CT(1c,C) AIX Commands Reference CT(1c,C)
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ct
PURPOSE
Dials an attached terminal and issues a login process.
SYNTAX
+-------+ +-------+ +------+ +------+ +------------+
ct ---| |---| |---| |---| |---| |--- telno --|
+- -wn -+ +- -xn -+ +- -h -+ +- -v -+ +- -s speed -+ +---------+
DESCRIPTION
The Basic Networking Utilities (BNU) command ct enables a user on a remote
ASCII terminal, such as an IBM 3161 or a DEC VT100, to communicate with an AIX
system over a telephone line attached to a modem at each end of the connection.
The user on the remote terminal can then log in and work on the AIX system.
A user on the local system issues ct with the appropriate telephone number,
telno, to call the modem attached to the remote terminal. The telno may
include the digits 0 - 9, minus signs (-) representing delays, equal signs (=)
representing secondary dial tones, asterisks (*), and pound/number signs (#).
The phone number may contain a maximum of 31 characters. If you have selected
a language (through the LANG environment variable) that supports multibyte
characters, the 31-character limit may be reduced by as much as 50%, depending
on the character code set being used.
When the connection is established, ct issues an AIX login prompt that is
displayed on the remote terminal. The user on the remote terminal enters an
AIX login name at the prompt, and AIX opens a new shell. The user at the
remote terminal then proceeds to work on the AIX system just like a local user.
The ct command is useful in the following situations:
o When a user working offsite needs to communicate with a local system under
strictly supervised conditions. Because the local system contacts the
remote terminal, the remote user does not need to know the phone number of
the local system.
o When the cost of the connection should be charged either to the local site,
or to a specific account on the calling AIX system. If the remote user has
the appropriate access permission and can make outgoing calls on the
attached modem, that user can make the equivalent of a collect call. The
remote user calls the specified local system, logs in, and issues the phone
number of the remote terminal with the -h flag. The local system hangs up
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CT(1c,C) AIX Commands Reference CT(1c,C)
the initial link so that the remote terminal is free for an incoming call,
and then calls back to the modem attached to the remote terminal.
The ct command is not as flexible as the BNU command cu. For example, the user
can not issue AIX commands on the local system while connected to a remote
system via ct. However, the ct command does have two features not available
with cu:
o The user can instruct ct to continue dialing the specified number until the
connection is established or a set amount of time has elapsed.
o The user can specify more than one telephone number at a time to instruct
ct to continue dialing each modem until a connection is established over
one of the lines.
If the user specifies alternate dialing paths by entering more than one number
on the command line, ct tries each line listed in the file
/usr/adm/uucp/Devices until it finds an available line with appropriate
attributes, or runs out of entries. If there are no free lines, ct asks if it
should wait for one, and if so, for how many minutes. The ct command continues
to try to open the dialers at 1-minute intervals until the specified time is
exceeded. The user can override this prompt by specifying a time with the -wn
flag when entering the command.
After the user logs out, ct prompts the user on the remote terminal with a
reconnect option; the system can either display a new login prompt or drop the
line.
Notes:
1. In order to establish a ct connection, the remote user generally contacts
a local user (with a regular phone call) and asks the local user to issue
the command.
2. Before issuing the ct command, be certain that the remote terminal is
attached to a modem that can answer the telephone.
FLAGS
-wn Allows the dialogue to be overridden by specifying n as the maximum
number of minutes that ct is to wait for a line. The command then dials
the remote modem at 1-minute intervals until the connection is
established or the specified time has elapsed.
-xn Used for debugging. Produces detailed information about the command's
execution on standard error output on the local system. The debugging
level, n, is a single digit between 0 and 9. The recommended default is
9.
-h Allows ct to hang up the current line to answer a return call.
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CT(1c,C) AIX Commands Reference CT(1c,C)
-v Allows ct to send a running narrative to standard error output.
-sspeed
Sets the data rate where speed is expressed in baud. The default is
1200.
EXAMPLES
1. To connect to a modem with an internal number 4-1589 (the - is optional):
ct 41589
The system responds:
Allocated dialer at 1200 baud
Confirm hang_up? (y to hang_up)
2. To dial a modem connected to a local telephone number (dialing 9 for an
outside line and specifying a 3-minute wait time):
ct -w3 9=2453017
3. To dial a long-distance number (specifying an outside line and a 5-minute
wait):
ct -w5 9=15026647003
FILES
/usr/adm/uucp/Devices Information about available devices.
/usr/adm/uucp/Dialcodes Dialing code abbreviations.
/usr/adm/uucp/Dialers Initial handshaking on a link.
/usr/adm/uucp/Permissions Access permission codes.
/usr/adm/uucp/Systems Accessible remote systems.
RELATED INFORMATION
See the following commands: "cu" and "login."
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