EasyServer II: Using the Communications Server

Contents: 

• Introduction
• Changing the Prompt
• Connecting to Services
• Sessions 
• Configuring your Port 
• Additional Local Server Commands 

Click Here to go to Using the Communications Server Part One

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Introduction 

This chapter focuses on using the Communications Server from a non-privileged port. The discussion assumes you do not have privileged access to the communications server and are confined to a subset of commands that allow you to modify your own port and display communications server characteristics and services. 

If you are working on a secure or limited view port, you may get error messages when trying some of the commands discussed. On a secure port you are restricted to commands that affect that port only. On a limited-view port, in addition, you are not able to SHOW or LIST services or Internet databases. 'Online Help' in this chapter tells you how to find out what commands are available to you. 

Commands and procedures are presented in this chapter in their simplest form. Refer to the EasyServer Command Reference Manual [PDF - 417KB]for additional information. 

Changing a Port Prompt 

The default port prompt is '%N %p>%P '. The %N is replaced by the communications server's name, or Local if there is no name assigned to the server. The %p is replaced by the current port number. And the %P signifies privileged mode by appending an angle bracket (>) to the prompt. If you haven't previously changed the default prompt or communications server name, the default prompt appears as Local 1> on the screen. 

You can change the default port prompt with the CHANGE PORT PROMPT command. For example, to change the port prompt to Deb>, type: 

Local 1> CHANGE PORT PROMPT 'Deb>' 

You can also use any combination of the special characters shown in the table below. 

Note: With the CHANGE PORT PROMPT command, you can also override any prompt changes made by a user with privileged access.

Table 6-2 Changing Prompts *   

 
* The examples shown in this table assume that you are using port 1 and have not previously changed the default prompt of the Communications Server.   

Refer to the EasyServer II Command Reference Manual [PDF - 417KB] for information about the CHANGE PROT PROMPT command. 

Connecting to Network Services 

From the communications server's local prompt, you can issue commands to connect to network services. The connection between a user and a service is called a session. The following sections explain how to establish sessions using: 

• Telnet 
• rlogin 

and also describes: 

• Setting up a Terminal Model String

Using Telnet  

From the Communications Server, you can establish a Telnet session using the CONNECT/OPEN TELNET command. 

The following example shows how to use the CONNECT/OPEN TELNET command to establish a Telnet session with a remote host named steve. 

Local 1> CONNECT TELNET STEVE 

Note: To connect to a remote host using the host name, the host name must be in the communications server's host table; otherwise, use the remote host's Internet address. 

In the previous example:  

• You can use OPEN instead of CONNECT. 
• If Telnet is the default protocol of the current communications server port, TELNET can be omitted.
• If Telnet is the default protocol of the current port and steve is the preferred host, use the CONNECT/OPEN command (followed by nothing else). 

From the communications server, you can use the DISCONNECT or CLOSE command to end the current session. 

From a remote host, you can establish a Telnet session with the Communications Server or a device attached to the server. The following example shows how to connect to a communications server named termserv. 

% TELNET TERMSERV 

To connect to a communications server using the host name, the host name must be in the remote host's host table; otherwise, use the server's Internet address. 

To establish a Telnet session with a device (such as a modem) attached to the communications server, specify the server's name or Internet address followed by the TCP port number of the device attached to the communications server. The following example shows how to connect to a device attached to a communications server named termserv at TCP port 2001. 

% TELNET TERMSERV 2001  

Refer to the following commands in the EasyServer II Command Reference Manual [PDF - 417KB] for more information: 

• CONNECT/OPEN 
• CONNECT/OPEN TELNET 
• DISCONNECT/CLOSE  

Using Rlogin  

From the Communications Server, you can establish an rlogin session using the CONNECT/OPEN RLOGIN command. 

To establish an rlogin session as a specific user, use the CONNECT/OPEN RLOGIN command, the host name or Internet address of the host to which you want to connect, followed by the user name. The following example shows how to use the CONNECT/OPEN RLOGIN command to establish an rlogin session with a remote host named sherril as user barbara. 

Local 1> CONNECT RLOGIN SHERRIL BARBARA  

Note: To connect to a remote host using the host name, the host name must be in the communications server's host table, otherwise, use the Internet address. 

The following example shows how to use the CONNECT RLOGIN command to establish an rlogin session with a remote host named sherril. 

Local 1> CONNECT RLOGIN SHERRIL  

In the previous example: 

• You can use OPEN instead of CONNECT. 
• You can add a user name to establish an rlogin session as a specific user. 
• If rlogin is the default protocol of the current communications server port, RLOGIN can be omitted. 
• If rlogin is the default protocol of the current port and sherril is the preferred host, use the CONNECT/OPEN command (followed by nothing else). 

From the communications server, use the DISCONNECT or CLOSE command to end the current session. 

Refer to the following commands in the EasyServer II Command Reference Manual [PDF - 417KB] for more information: 

• CONNECT/OPEN 
• CONNECT/OPEN RLOGIN 
• DISCONNECT/CLOSE 

Setting Up a Terminal Model String 

You can set up a terminal model string for a port. This model string is passed to a remote host when a Telnet or rlogin session starts. In a UNIX environment, the terminal model string is used to specify a different terminal type for use with termcap or terminfo. You do not need to set the terminal model string if the communications server's default string is useable. The following example shows how to set up a terminal model string for use with termcap on a Wyse WY-60 terminal in 132 column mode: 

Local 1>> CHANGE PORT TERMINAL wy60-w  

Sessions 

This section outlines the following topics: 

• Switching Sessions
• Using the FORWARDS or BACKWARDS Command
• Using Mapped Keys
• Using the RESUME SESSIONS Command
• Using Toggle Keys
• Displaying Multiple Sessions
• Disabling Multiple Sessions

Any connection to a service or remote host is called a session. The Communications Server supports up to eight separate sessions on any one port. If, for example, your port has access to many different remote hosts, you can establish a connection with two, three, or more of them (to a maximum of eight sessions). Then you can switch easily among the resulting sessions. Sessions can be opened using the TELNET or RLOGIN commands. 

While each session can receive information from its host, only one session at a time can receive input from the keyboard. The session connected to the keyboard is called the active session. 
 

Establishing More than One Session  

You can establish more than one session in the same way you would normally connect to a single session. To enable more than one session: 

Step 1.  From within an active session, press the Break key to return to the communications server prompt. (Refer to your terminal documentation if you're not sure which is the Break key on your keyboard.) The session that was active when you pressed the Break key continues although it's no longer displayed. 

Step 2.  From the communications server prompt, enable another session. (For example, use the TELNET TOPDOC command to connect to a host named topdoc.) 

Step 3.  Repeat steps 1 and 2 until you've enabled the desired number of sessions or reached the eight-session-per-port limit. 
 

Switching Sessions  

You can switch sessions using: 

FORWARDS or BACKWARDS.  These commands let you switch to the next or previous session. 

Mapped keys.  These keys let you specify keys for forwards and backwards switching. 

RESUME SESSIONS.  This command lets you resume a specific session. 

Toggle keys.  These keys are previously set up by the terminal manufacturer to let you switch between active sessions. 

To view the status of the current sessions, type: 

Local 1> SHOW SESSIONS 

A display similar to the following appears: 

Port 1:     jozef         Current Session: 1 
       Session 1: Protocol: TELNET  Host: topdoc 
       Session 2: Protocol: TELNET  Host: docserv 
       Session 3: Protocol: TELNET  Host: blazer 

Local 1> 

The first line of this display shows your port number, user name, and current session number. The next three lines describe other active sessions. 
 

Using the FORWARDS or BACKWARDS Command  

From the communications server prompt, switch to the next active session by typing: 

Local 1> FORWARDS  

For example, if you're in session 2, type FORWARDS to switch to session 3. 

Or you can switch to the previous active session by typing 

Local 1> BACKWARDS  

For example, if you're in session 2, type BACKWARDS to switch to session 1.  

Using Mapped Keys  

You can map keys to switch among sessions without returning to the communications server prompt. Pressing a switch key (mapped key) is the same as pressing the Break key from within a session and then typing the FORWARDS or BACKWARDS command. Switch keys cycle you through multiple sessions the same as the FORWARDS and BACKWARDS commands. If you have only two sessions connected, pressing either switch key returns you to the inactive session. 

Switch keys must be control key combinations. Do not define as switch keys any keys or key combinations you are likely to use in an application, because pressing those keys will interrupt your session. 

In the following example, the forward switch is set to <Ctrl> F and the backward switch is set to <Ctrl>  B  on port 3. (Refer to the commands SET/DEFINE/CHANGE PORT FORWARDS SWITCH and SET/DEFINE/CHANGE PORT BACKWARDS SWITCH in the EasyServer II Command Reference Manual.) 

Local 1> SET PORT FORWARDS SWITCH ^F BACKWARDS SWITCH ^B  

Note:  Normally, to indicate a control character, enter either a carat (^) followed by the character or type the control character literally (hold down <Ctrl> while pressing the character). In the example above where ^B is used as the BACKWARDS switch, use the carat notation because <Ctrl> B is the line editing function for going to the beginning of the line in local mode. 

To nullify a switch key assignment, substitute NONE for the control key combination as follows: 

Local 1> SET PORT FORWARDS SWITCH NONE  

To switch among sessions, press the mapped control key combination to move forwards or backwards, then press <Enter>. For example, if <Ctrl> F is designated for switching forward to the next session, type <Ctrl> F then press <Enter>. 

You can temporarily disable switch keys for a particular session with the SET TELNET CLIENT PROFILE command (refer to the EasyServer II Command Reference Manual [PDF - 417KB]). The switch keys remain in effect outside the session. 
 

Using the RESUME SESSIONS Command  

From the communications server prompt, you can switch to any session directly by typing the RESUME command. To resume a particular session, type 

Local 1> RESUME SESSION session_number  

Where session_number is the number of the session you want to resume. For example, if you have three sessions active and you want to resume session 2, type: 

Local 1> RESUME SESSION 2  

To resume the last active session, type: 

Local 1> RESUME  

Using Toggle Keys  

You can also use toggle keys to switch between two sessions that appear on the screen at the same time. Refer to your terminal documentation for more information. 

Displaying Multiple Sessions  

If your terminal supports Session Support Utility (SSU), you can display multiple sessions (in most cases, two) at the same time. You can still enable up to eight terminal sessions. 

To configure the Communications Server to display multiple sessions: 

• Configure your terminal for SSU. (Refer to your terminal documentation for instructions.) 
• Type: 

Local 1> SET PORT MULTISESSION ENABLED  

to enable SSU on the current port. The following message appears on the screen if SSU is enabled on the communications server port: 

Done 

If your terminal is not set up correctly, meaningless characters spill onto the screen, and the following message appears: 

Local -037- Session management terminated  

(Refer to your terminal documentation for more information about configuring your terminal for SSU.) 

Press <Enter> and the following prompt appears on the screen: 

Service Name=  

Enter a host name or Internet address to connect to a remote host. For example, you could type topdoc to connect to a host named topdoc. The following message appears on the screen: 

Session opened  

Or you can press <Enter> to enable another session in local mode (at the communications server prompt). 

Note:  For instructions about how to enable more than one session, see 'Establishing More than One Session' earlier in this section. 

To disable multiple sessions and SSU, see the next section, 'Disabling Multiple Sessions.' 

  Disabling Multiple Sessions  

To disable SSU and disconnect any remote sessions: 

Step 1.  
Return to the communications server prompt by pressing the Break key. (Refer to your terminal documentation if you're not sure which is the Break key on your keyboard.) 

Step 2.  
From the communications server prompt, type: 

Local 1> SET PORT MULTISESSION DISABLED  

All active sessions on the current port are discontinued. If you have several sessions enabled, messages such as the following appear: 

Local -012- session 1 [topdoc] disconnected  
Local -012- session 2 [topdoc] disconnected  
Local -012- session 3 [topdoc] disconnected  
Local -012- session 4 [topdoc] disconnected  
Local -012- session 5 [topdoc] disconnected  
Local -037- Session management terminated  
 

Configuring Your Port 

The Communications Server provides you with a wide range of commands to configure your port for very specific uses. 

Table 6-3 lists the keywords available to non-privileged users with the SET/DEFINE/CHANGE command set.  Note, however, that as a non-privileged user you can change only your own port settings. 

Changes to the operational database (SET command) take effect immediately but are lost when you log out of the communications server. 
To save your port settings, instead of logging out when you've 
finished working with the server, use the LOCK command (see "Additional Local Server Commands" later in this chapter) to password-protect your communications server port. 

Use the keywords listed in Table 6-3 (below) with the SET PORT command. 

Refer also to the EasyServer II Command Reference Manual [PDF - 417KB] for a full discussion of command syntax before trying these commands. 
As an alternative to this process, a forms based port configuration utility is available via a web browser. 
For more information about this facility, please refer to the 'HTTP (Web) Service' section in the Server Administration section. 

Table 6- 3:  
Non-privileged SET/DEFINE/CHANGE PORT Command Keywords. 

 

Additional Local Server Commands 

Some additional commands are available to you in local mode that do not involve port configuration, sessions, or connecting to services. 

The following topics are discussed below: 

• BROADCAST
• LOCK
• PING/TEST INTERNET
• Status Displays

BROADCAST  
The BROADCAST command allows you to send messages to other users on the Communications Server if your system administrator has enabled this command. To broadcast a message to port 5, for example, type: 

Local 1> BROADCAST PORT 5 'Still on for Lunch?'  

Note:  If you don't use quotes, the message automatically appears in uppercase. 
 

LOCK  
The LOCK characteristic allows you to restrict access to your port without logging out, if your system administrator has enabled it. To lock your terminal port, type LOCK at the local prompt. Type your password when prompted (it is not echoed). You are prompted to verify the password by typing it again (also not echoed). 

Passwords can be from 4 to 16 characters. 
Your terminal remains locked until you enter the password and your local prompt appears. Note that a privileged user is still able to log out of your port with the LOGOUT command. 
 

PING/TEST INTERNET  
The PING, or TEST INTERNET, command allows you to test for TCP/IP network connections. 

For example, to determine if host enghost is accepting network requests, enter: 

Local 1> PING enghost 

The ping command is run 23 times and then the results are summarised. To specify a different number of times to run, refer to the PING command in the EasyServer II Command Reference Manual. 

If you do not have nameservice or do not have an entry for enghost in your local host names table, enter the Internet address of the host, for example: 

Local 1> TEST INTERNET 123.4.5.6  
 

STATUS DISPLAYS  
The SHOW/LIST command set allows you to display information about your port, the server, and services available to you. Except where noted, each command can be used with any of the keywords listed in Table 6-3. The two commands that make up the SHOW/LIST command set differ as follows: 

• SHOW displays a snapshot of operational database status. 
• LIST displays a snapshot of permanent database status. 

Although all status display commands can be executed with just the keywords listed in Table 6-3, many take options, and some restrictions apply. To take full advantage of the command set and avoid errors, look up the commands in the EasyServer II Command Reference Manual [PDF - 417KB] or in the Online Help before you try them. 
 

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