To use ISDN, you initiate a connection to a remote system or network in one shell window, then use another shell window to log in to or transfer files between your system and the remote system or network.
The connection uses PPP (Point-to-Point Protocol). For more information than is available in this chapter, see the ppp man page.
This chapter contains these sections:
When you start an ISDN connection, you are placing a telephone call from your system to another system. The telephone company charges you by the minute while the connection is open, regardless of whether you are actively transferring files or are logged in to a remote system. Be sure to close the connection when you are not using it (see “Stopping an ISDN Connection”).
Only the Administrator can start an ISDN connection. Follow these steps:
Log in as root through a shell window.
Choose “Unix Shell” from the Desktop toolchest.
Position your cursor within the new window and type:
login root
If a prompt for a password appears, type the password then press <Enter>. If a prompt appears but the root account has no password, just press <Enter>.
If you like, you can monitor the progress of the ISDN connection or of PPP in a separate shell window.
To monitor the progress of the ISDN connection, open another shell window, and type:
isdnstat
When you actually place the call in the next step, isdnstat reports the progress of the call. For more details, see the isdnstat man page. To stop isdnstat from running, type:
q
To monitor the progress of PPP, open another shell window, and type:
netstat -C
When you place the call in the next step, the asterisk (*) next to the ppp0 listing should disappear. For more details, see the netstat man page. To stop netstat from running, type:
q
In the shell window in which you are logged in as root, start an ISDN connection to a system whose information your entered in “Building a List of Remote ISDN Systems and Networks” by typing:
ppp -r <hostname of remote system>
For example, to connect to the system named mars, type:
ppp -r mars
After several seconds, you'll know the connection is established and ready to use when you see a message similar to this:
ppp[395]<host> IPCP1 ready: <IP addr> to <IP addr>
If you see a different message, see “Troubleshooting the ISDN Connection.”
Do not close the shell window in which you started the connection; the window must remain open to keep the connection open. You may want to resize or minimize the window to save screen space.
To use the connection, see “Logging In to Remote Systems” and “Transferring Files Across an ISDN Connection.”
To close the connection, click the minimized icon of the window in which you made the connection (if you minimized it), position your cursor over the window, and type:
<Ctrl-c>
The connection is closed when you see the system prompt.
 | Note: Be sure to close your ISDN connection when you are not using it. As long as the connection is open, your telephone company charges you just as it does for a standard telephone call. |
Once the ISDN connection is open (see “Starting an ISDN Connection”), you can log in to:
the remote system to which you connected using ISDN
any remote system that's on the same network as the system to which you connected, and whose hostname and IP address appear in your /etc/hosts file. For more information, see “Adding Remote Systems to the /etc/hosts File.”
To log in to a remote system, follow these steps:
Choose “Unix Shell” from the Desktop toolchest.
You can log in to the system using either the rlogin command or the telnet command.
To use rlogin, position your cursor over the shell window and type:
rlogin <remote hostname> -l <your login name>
You are logged in when you see the remote system's prompt. For more information, see the rlogin man page.
If you do not see the prompt after several seconds, type:
<Ctrl-c>
To use telnet, position your cursor over the shell window and type:
telnet <remote hostname>
When the remote system responds, you see a login prompt. Type your login name, and, if requested, your password. For more information, see the telnet man page.
If you do not see the prompt after several seconds, type:
<Ctrl-c>
To log out of a remote system, type:
logout
When you are finished using the remote system, you may want to close your ISDN connection; see “Stopping an ISDN Connection.”
Once the ISDN connection is open (see “Starting an ISDN Connection”), you can transfer files between your system and:
the remote system to which you connected using ISDN
any remote system that's on the same network as the system to which you connected, and whose hostname and IP address appear in your /etc/hosts file. For more information, see “Adding Remote Systems to the /etc/hosts File.”
You can transfer files using any of several transfer utilities. See “Copying Files Across the Network” in the online document IRIS Essentials for details on copying files graphically using the Indigo Magic desktop, and for an overview of rcp and ftp. For more details on rcp and ftp, see their man pages.
If you encounter any problems copying files, first make sure that you can successfully log in to the remote system; see “Logging In to Remote Systems.” If you cannot log in, see “Troubleshooting the ISDN Connection.” If you can log in but still cannot successfully transfer files, see the man page for the utility you are using, or see IRIS Essentials.
Only the Administrator can stop (close) an ISDN connection. Be sure to close the connection when you are not using it; the telephone company charges you by the minute while the connection is open, regardless of whether you are actively transferring files or are logged in to a remote system.
To close the connection, follow these steps:
If the window in which you started the connection is minimized, click it to open it.
Position your cursor over the window in which you started the connection, then type:
<Ctrl-c>
The connection is closed when you see the system prompt.