Network Terminal Accelerator Installation and Configuration Support

The following information helps system administrators and Network Terminal Accelerator software application writers understand the installation and configuration support requirements for the adapter program.

This section discusses:

• Software Distribution
• Target Directories
• System Configuration
• Download
• Terminal Connectivity Services
• TCP/IP Configuration
• MLI Ethernet Interface
• SNMP Management

Software Distribution

The adapter directories and files contain the sample programs and executable files to support the adapter. The software distribution contains the following components:

Target Directories

The executable images from the software distribution are installed in the following directories:

System Configuration

The ODM database maintains the system configuration and driver support. The system configuration includes ODM device object classes and configuration methods that manage the database for the adapter. Additionally, the /etc/inittab file is modified during the adapter's installation to support the product's initialization.

Device Driver Configuration Methods

The device driver configuration methods manage the ODM database for the adapter. Each device driver has a set of configuration methods. They define the run-time attributes and channel configuration to the AIX system. The following table contains the device drivers and methods.

The configuration methods are run automatically during a system restart. To run them from the command line, use the cfgmgr command.

Inittab File

The /etc/inittab file contains entries to execute adapter initialization commands and to enable logins. The /etc/rc.ntx file is called by the inittab file and contains the adapter's initialization commands.

The /etc/rc.ntx file contains shell script command lines. The commands run at the conclusion of the system boot procedure. You can use the /etc/rc.ntx file to perform site-specific configuration commands such as setting the adapter Internet addresses, default route, and hty device call-type and protocol-port parameters.

The /etc/inittab file contains hty device entries. These entries identify the hty device, run level, action, and getty login process. The default run level is 2, and the default action is off. The penable and pdisable commands enable and disable logins for an hty device. The following hty device entry defines hty device 7:

hty7:2:off:/usr/sbin/getty /dev/hty7

Refer to the rlogin command information in "Host Commands" for information on how to enable automatic logins.

Man Pages

The Network Terminal Accelerator software is distributed with AIX-style man pages. The man pages describe the adapter commands, library routines, and special files. Refer to AIX Version 4.3 Commands Reference for more information on the Network Terminal Accelerator commands.

Note: In AIX Versions 3.2 through 4.2, the InfoExplorer package must be installed to access the man pages.

Download

Two versions of the download image file are installed in the /usr/lib/microcode directory. The ntx8023.04F.00 file is downloaded when the adapter is configured with the TCP Protocol Timeout value set to long (default value). Otherwise, the ntx023.04F.01 file is downloaded. The /usr/bin/ntx_load command transfers the download image to the adapter. The cfgrhp configure method runs the ntx_load command to download the adapter at system startup.

You must restart the system after the software installation. The reboot procedure loads the new drivers and downloads the adapter's program. To verify the driver software installation and download image, use the ntx_ver command after the system boots. The following command retrieves and displays the software version information from the adapter drivers and download image for the /dev/rhp1 adapter:

ntx_ver -d/dev/rhp1

Title: NTX-8023 Download Software 
Version: 04F 
Date: Dec 28 09:49:43 1995 
Description: TCS/Telnet with TCP/IP 
       
Title: rhp 
Version: 01A 
Creation Date: Feb 6 18:54:36 1996 
Description: Network Terminal Accelerator Raw Driver 
 
Title: mli 
Version: 01A 
Creation Date: Feb 6 18:55:59 1996 
Description: Network Terminal Accelerator MLI Driver

The adapter program does not accept download requests until the self-test sequence completes.

Terminal Connectivity Services

The following terms are essential to understanding how the Network Terminal Accelerator adapter's terminal services configuration works:

Channel Definition

The adapter's software provides standard Telnet and rlogin protocol services to support network virtual terminal sessions for hty devices. The AIX htydd device driver in conjunction with the adapter's terminal control software (TCS) manage the session logins.

The htydd device driver interfaces the host applications to the TCS and manages the POSIX-line discipline emulation. The TCS performs the line-discipline character processing on the input and output data streams. The tty configuration defines the hty device characteristics.

The hty channels are allocated to the adapters and defined to the htydd device driver and TCS with the /usr/bin/hty_load command. The hty_load command reads the /etc/hty_config configuration file, which contains the hty channel assignment for the adapters in the system.

The Network Terminal Accelerator configuration methods generate the hty_config file based on each adapter's no_of_htys attribute. You can set this attribute in the Number of Channels to Configure field in the Set GLOBAL Modes SMIT menu.

The hty_config file has the following format:

• Comment lines start with the # (pound sign) in the first column.
• Blank lines are ignored.
• Fields for each entry are delimited by tabs or spaces.
• One entry for each adapter.
• The first field of an entry is the adapter minor number X from /dev/rhpX.
• The second field is reserved and must always equal 1.
• The third field is the number of hty devices. For the Network Terminal Accelerator-256, this may be any number from 1 to 256. For Network Terminal Accelerator-2048, this may be any number from 1 to 2048.

This is a sample hty_config file. It defines 256 hty channels for the /dev/rhp0 adapter, 2048 hty channels for the /dev/rhp1, and 700 hty channels for /dev/rhp2. Both /dev/rhp1 and /dev/rhp2 must be Network Terminal Accelerator-2048 models for the configuration to be valid.

# Adapter      Cluster           Number 
# minor #      address           of channels 
    0             1                256 
    1             1                2048 
    2             1                700

Default Protocol-Port Services

The adapter's software binds services to numbered protocol-ports. The ntx_pserv command modifies and displays the protocol-port assignments. The following list contains the default protocol-port and service relationships:

Configuring Channels and Services

The default channel configuration for the adapter TCS is call-in mode with dynamic channel assignment. In call-in mode, the TCS accepts connection requests from user terminals and establishes a connection to any defined service. The default channel protocol-port number is 0, which specifies dynamic assignment of sessions to channels based on the port to which the original incoming connection request was directed. For example, when an incoming connection request arrives on port 23, the TCS will automatically assign its Telnet service to handle data that passes through that connection. The first available channel supporting the Telnet service is selected for the connection.

If the remote device is passive (for example, a printer or dial-out modem) and cannot initiate the connection request, the hty channel may be configured in call-out mode. In this mode, the TCS initiates the connection request to a specific remote IP address and protocol port number whenever an application opens the hty device mapped to that channel.

Call-in channels may be configured for dynamic or fixed channel assignment. Call-out channels always use fixed channel assignment.

Dynamic Assignment for Call-In Channels

The Network Terminal Accelerator adapter can accept connection requests from terminal servers or remote clients and dynamically assign each session to an available channel. In this mode, the adapter waits for incoming connection requests. The first available open channel is assigned as requests arrive at the adapter. Since the correspondence between the channels and the AIX devices is fixed, a terminal may become connected to any /dev/hty device, depending on when you logged on.

In the Configuring Channels and Services figure, channels 000 , 005 , and 686 were connected to terminals in this fashion. At the time the session on channel 000 was established (when an rlogin session on the host was requested), channel 000 was the lowest-numbered open, unconnected channel available for an rlogin connection. The initial request arrived on TCP port 513 (the "well-known" rlogin port) and the adapter's rlogin service honored the request by establishing a new rlogin session on channel 000 . The session on channel 005 was set up in exactly the same way. In this case, the initial request was for a Telnet session and arrived on TCP port 23 .

Also, as illustrated in the "Configuring Channels and Services" figure, the adapter will honor the next request that arrives on port 23 for a Telnet session by connecting channel 145 to the Telnet service. Note that channel 100 is unavailable to the Telnet service since it is reserved for exclusive use of the rlogin service.

Fixed Assignment for Call-In Channels

It may be necessary to establish a fixed relationship between a particular terminal (or printer or modem) on the network and a particular AIX logical device. For example, a print spooler must know which device to open to send output to its printer. In some applications, it may be desirable to establish such a fixed relationship for user terminals as well.

Remote devices normally direct their connection requests to "well known" port numbers on the Network Terminal Accelerator adapter (for example, port 23 for Telnet and port 513 for rlogin). The adapter assigns these connections to the first available open channel. If desired, channels can be assigned specific address/port pairs. Remote users can then direct their connection requests to a specific address or port and know the channel (/dev device) to which they will be connected.

In the "Configuring Channels and Services" figure, channel 694 is configured to only accept rlogin connection requests directed specifically to TCP port 9998 . To make proper use of this facility, the system administrator can take steps to ensure that only one user requests connections to this particular port by, for example, appropriately configuring the user's terminal server.

To establish the configuration for channel 694 as shown in the "Configuring Channels and Services" figure, both the ntx_pserv and ntx_chaddr commands must be used. The ntx_pserv command can be run any time after the board is downloaded (even before the ntx_ifcfg command is run). It associates Network Terminal Accelerator services with ports or ranges of ports. For example, the following would assign the rlogin service to ports 9998 and 9999 :

%ntx_pserv rlogin 9998-9999 tcp

After the hty_load command establishes the channel configuration, use the following command to associate channel 694 with port 9998:

%ntx_chaddr -p 9998 694  

In both examples, assume that the adapter being configured is the default /dev/rhp0 .

Use the following procedures to configure call-in channels for fixed assignment to addresses and/or ports. When the desired configuration has been established and tested, you must add the ntx_pserv and/or ntx_chaddr commands to the end of the /etc/rc.ntx file to restore the configuration after every system boot.

Fixed Assignment Using Address/Port Number Pairs from the Command Line

1. Use the ntx_pserv command to assign the desired port numbers to the Telnet or rlogin service. Use port numbers > 2048, since port numbers 0-2048 are reserved by convention and may be defined for other services.
2. Use the ntx_chaddr command to assign one of the defined port numbers to a channel. The assignment of an IP address is optional with ntx_chaddr. If no IP address is specified, the channel remains assigned to the default IP address for the adapter hty interface (as shown by the ntx_ifcfg command).
3. On the remote terminal or client, enter telnet IP_Address Port_Number to establish a connection with the hty channel specified in step 2.
4. After testing the new configuration, add the ntx_pserv and ntx_chaddr commands to the /etc/rc.ntx file.

Fixed Assignment Using Address/Port Number Pairs from SMIT

1. Use the ntx_pserv command to assign the desired port numbers to the Telnet or rlogin service. Use port numbers > 2048, since port numbers 0-2048 are reserved by convention and may be defined for other services.
2. Use the smit htyDevice_menu fast path to access the HTY Devices menu.
3. Select Configure HTY Channels.
4. Enter the adapter name in the Network Terminal Accelerator Adapter field.
5. Accept Call-in as the Call Type field value.
6. Leave the Service field blank.
7. Enter the desired Protocol Port Number and Channel Number.
8. Enter the desired Internet Address. This field is optional.
9. On the remote terminal or client, enter telnet IP_Address Port_Number to establish a connection with the hty channel specified in step 7.
10. After testing the new configuration, add the ntx_pserv and ntx_chaddr commands to the /etc/rc.ntx file.

Fixed Assignment Using Addresses from the Command Line

1. Use the ntx_chaddr command to assign a unique IP address to each channel requiring fixed assignment. The default IP address for the adapter hty interface (as shown by the ntx_ifcfg command) remains assigned to all other channels.
2. On the remote terminal or client, enter telnet IP_Address to establish a connection with the hty channel specified in step 1.
3. After testing the new configuration, add the ntx_chaddr command to the /etc/rc.ntx file.

Fixed Assignment Using Addresses from SMIT

1. Use the smit htyDevice_menu fast path to access the HTY Devices menu.
2. Select Configure HTY Channels.
3. Enter the adapter name in the Network Terminal Accelerator Adapter field.
4. Accept Call-in as the Call Type field value.
5. Leave the Service field blank.
6. Enter the desired Internet Address and Channel Number.
7. On the remote terminal or client, enter telnet IP_Address to establish a connection with the hty channel specified in step 6.
8. After testing the new configuration, add the ntx_chaddr command to the /etc/rc.ntx file.

Fixed Assignment for Call-Out Channels

The call-out mode can be used to establish a fixed relationship between remote devices and Network Terminal Accelerator adapter channels. This method is best suited for passive devices, such as printers and dial-out modems, which cannot take the initiative to request a connection. This feature can also be used to establish connections to user terminals.

When a host process (for example, getty or a print spooler) opens a device mapped to a call-out channel, the adapter attempts to connect to a predefined remote address and port. If the connection is established, the host process is able to transfer data to and from the remote port.

To operate channels in call-out mode, the channel must be configured to make an outgoing connection request to a specific address and port, and the remote device must be configured to accept an incoming connection request on the same address and port.

In the "Configuring Channels and Services" figure, channel 422 has been configured for call-out using the Telnet service. This channel has been opened by the system line-printer daemon. At the remote end of this connection, there is a terminal server with an attached printer. The adapter automatically assigns port numbers to its end of the call-out connections. Ports are assigned starting at number 1024 and working consecutively upward.

To establish the configuration for channel 422 as shown in the "Configuring Channel and Services" figure, enter:

%ntx_chaddr -c telnet -p 2000 -i termserv_3 422

The host must be able to resolve the name termserv_3 to a reachable IP address (the address of the terminal server to which the line printer is connected). Also, the terminal server must be configured to accept a Telnet connection request on its port 2000 , and honor this request by establishing a Telnet session with the physical I/O port to which the printer is attached. The following figure shows both ends of such a printer connection after it has been established.

Use the following procedure to configure call-out channels for fixed assignment to addresses and ports. When the desired configuration has been established and tested, you must add the ntx_chaddr command to the end of the /etc/rc.ntx file to restore the configuration after every system boot.

Fixed Assignment Using Addresses and Ports from the Command Line

1. Use the ntx_chaddr command to specify the remote service and IP address for each channel requiring fixed assignment. Specifying a service enables the channel as call-out. The assignment of a port number is optional. If no port number is specified, the "well-known" port number for the service is used.
2. On the remote terminal server or client system, configure the same service, port, and IP address for the remote device to be connected with the hty channel specified in step 1.
3. After testing the new configuration, add the ntx_chaddr command to the /etc/rc.ntx file.

Fixed Assignment Using Addresses and Ports from SMIT

1. Use the smit htyDevice_menu fast path to access the HTY Devices menu.
2. Select Configure HTY Channels.
3. Enter the adapter name in the Network Terminal Accelerator Adapter field.
4. Enter Call-out in the Call Type field.
5. Enter the desired Service, Internet Address, and Channel Number.
6. Enter the desired Protocol Port Number. This field is optional.
7. After testing the new configuration, add the ntx_chaddr command to the /etc/rc.ntx file.

TCP/IP Configuration

The adapter supports network virtual terminal sessions on hty devices in a TCP/IP environment. You must set the adapter's Internet address for this hty interface in the ODM database to enable the Ethernet interface controller. You set the Internet address during installation using the System Management Interface Tool (SMIT). After installation, the configuration methods run the ntx_ifcfg command at system startup. The ntx_ifcfg command modifies and displays the adapter's network interface and broadcast addresses for the hty interface.

You can set the network address manually using the ntx_ifcfg command. The following command configures the /dev/rhp1 adapter with Internet address 192.6.153.90:

ntx_ifcfg -d/dev/rhp1 -i 192.6.153.90

You can also use the ntx_ifcfg command to display the adapter's Internet address and state of the adapter's network interface. The following commands retrieve and display the Internet addresses for the /dev/rhp1 and /dev/rhp2 adapters:

ntx_ifcfg -d/dev/rhp1 
ie0: flags=63<UP,BROADCAST,NOTRAILERS,RUNNING> 
inet 192.6.153.90 netmask ffffff00 broadcast 192.6.153.255
 

ntx_ifcfg -d/dev/rhp2 
ie0: flags=02<BROADCAST> 
inet 0.0.0.0 netmask 00000000 broadcast 0.0.0.0

The ntx_ifcfg command reports that no Internet address has been specified for the /dev/rhp2 adapter.

The ntx_ping command verifies the operational state of the adapter's Ethernet controller and network connection. It asks the adapter to send an Internet Control Message Protocol (ICMP) echo request datagram (ping) to an active host on the network.

Note: The ntx_ping command accepts the dotted decimal Internet address notation or host name from the /etc/hosts file.

The following example displays both the command that pings a host machine named bach and the system response to the command:

ntx_ping bach 
bach is alive

In addition to the ntx_ifcfg and ntx_ping commands, the adapter software provides the following commands to manage adapters in a TCP/IP environment:

MLI Ethernet Interface

The adapter's MAC Layer Interface (MLI) is an Ethernet device driver for the host TCP/IP network interface driver. The network interface driver is identified as enX, where X equals 0 for the primary network interface, 1 for the secondary network interface, and so forth. The MLI devices are identified as /dev/entX, where X is the MLI device minor number.

The ifconfig command binds the /dev/enX network interface driver to the /dev/entX Ethernet device driver. The following command enables the primary network interface driver on MLI device /dev/ent0:

ifconfig en0 HostName

where the /etc/hosts file defines the host specified by the HostName parameter.

The following command disables the primary network interface driver on MLI device /dev/ent0:

ifconfig en0 detach

SNMP Management

The adapter program supports the Simple Network Management Protocol (SNMP). The adapter's SNMP agent complies with the Management Information Base (MIB) II (RFC 1213) and SNMP protocol (RFC 1157). The following commands allow you to manage and configure the adapter's SNMP: