Contents for TN3270 Service

  Accessing Microsoft Support Services

  Getting Started with TN3270 Service

  Identifying Elements in TN3270 Service Administration Display

  Configuring TN3270 Service

  Specifying Administrative Options

  Administering TN3270 Service

  Using TN3270 Trace Option

  Warning messages

For Help on Help, Press F1.


Accessing Microsoft Support Services

When you have a question

If you have a question about TN3270 Service, first look in the product documentation. If you cannot find the answer, please see the SNA Server Administration Help for instructions on how to contact the Microsoft Support Network.


Getting Started with TN3270 Service

Overview

TN3270 Service combines client/server architecture with the power and productivity of the Windows NT system. By using TN3270 Server you can provide access to your host mainframe environment for TN3270 clients using 3270 terminal emulation services. TN3270 Service also includes support for TN3270E clients, including printing.

TN3270 Service is implemented as a Windows NT Service in the SNA Server environment. SNA Server and TN3270 Service communicate via SNA Server-based Logical Unit Application programming interface (LUA). TN3270 Service communicates with TN3270 clients over a TCP/IP connection using the TN3270 protocol.

TN3270 Service is a client to the SNA Server and a server to TN3270 clients.


Identifying Elements in TN3270 Service Administration Display

Client Address, LU Name, and State of each defined client is displayed in the Session Status area of the TN3270 Administration Display.

From the TN3270 Administration dialog box, you can monitor network activity including the State of each LU or Pool. An LU or Pool will display one of the following States:

State	Description
CONNECTED	The TN client has established a connection to TN3270 Service.
SSCP-LU	The TN client has established a connection to VTAM.
LU-LU	The LU is bound to a host application.
TERM	The connected session is terminating.
From the TN3270 Administration dialog box, you can select one of the following options:

Option	Description
Close	TN3270 Session Administration dialog box closes.
Config	Configure LUs for TN3270 dialog box appears, allowing you to proceed with LUA LU and Pool configuration, including assigning IP addresses.
Options	TN3270 Options dialog box appears, allowing you to define additional administrative features such as idle time out or the use of a local domain name resolver.
Trace	Trace Options dialog box appears, allowing you to define and initiate a trace.
About	TN3270 Service version and release information is displayed.
Refresh	Information displayed in the Session Status dialog box is updated.
Help	TN3270 Service help text is activated.


Configuring TN3270 Service

  Adding An LU

  Deleting LUs

  Editing A TN3270 LU Configuration

  Zooming LUs

  Saving TN3270 Configuration

  Reopening TN3270 Configuration

  Backing Up TN3270 Configuration

  Restoring TN3270 Configuration


Adding An LU

By adding an LU you are defining SNA resource access to TN3270 Service and you are defining logmode entries that are associated with an SNA resource.

  To add a single LU or Pool to TN3270 Service

  To add multiple LUs or Pools to TN3270 Service


To add a single LU or Pool to TN3270 Service

To add a single LU or Pool to TN3270 Service

1.	From the TN3270 Administration dialog box, choose the Config button.

The Configure LUs for TN3270 dialog box appears.

2.	From the Available LUs / Pools list, select an LU or Pool.

3.	Choose the Add button.

The LU or Pool will move into the Configured LUs / Pools list box on the right. By default, the LU or Pool will be assigned an IP address of 0.0.0.0 and a subnet mask of 0.0.0.0. This will allow any TN3270 client to use this LU or Pool.

4.	To specify one or more client IP address(es) for this LU or Pool, see Editing a TN3270 LU Configuration.


To add multiple LUs or Pools to TN3270 Service

To add multiple LUs or Pools to TN3270 Service

1.	From the TN3270 Administration dialog box, choose the Config button.

The Configure LUs for TN3270 dialog box appears.

2.	From the Available LUs / Pools list, select multiple LUs or Pools.

A contiguous range of LUs or Pools can be selected by using the pointing device to select the first item in the range you want to add, holding down the SHIFT key, and using the pointing device to select the last item in the range you want to add.

A noncontiguous range of LUs or Pools can be selected by using the pointing device to select each item in the range you want to add, while holding down the CTRL key.

3.	Choose the Add button.

The LUs or Pools will move into the Configured LUs / Pools list box on the right. By default, the LUs or Pools will be assigned an IP address of 0.0.0.0 and a subnet mask of 0.0.0.0. This will allow any TN3270 client to use these LUs or Pools.

4.	To specify one or more client IP address(es) for these LUs or Pools, see Editing a TN3270 LU Configuration.


Deleting LUs

  To delete a single LU or Pool from TN3270 Service

  To delete multiple LUs or Pools from TN3270 Service


To delete a single LU or Pool from TN3270 Service

To delete a single LU or Pool from TN3270 Service

1.	From the TN3270 Administration dialog box, choose the Config button.

2.	From the Configured LUs / Pools list, select an LU or Pool.

3.	Choose the Delete button.

The selected LU or Pool is reinstalled in the Available LUs / Pools list.

4.	Choose the Save button to save your configuration changes.

5.	Choose the Close button.

Note   Configuration changes are apparent only to users who establish a connection after the configuration changes are saved. Users who were connected at the time the configuration changes were made will not be affected.


To delete multiple LUs or Pools from TN3270 Service

To delete multiple LUs or Pools from TN3270 Service

1.	From the TN3270 Administration dialog box, choose the Config button.

2.	From the Configured LUs / Pools list, select LUs or Pools you wish to delete.

A contiguous range of LUs or Pools can selected by selecting the first item in the range you want to delete, holding down the SHIFT key, and selecting the last item in the range you want to delete.

A noncontiguous range of LUs or Pools can be selected by using the mouse to select each item in the range you want to add, while holding down the CTRL key.

3.	Choose the Delete button.

The selected LU or Pool reappears in the Available LUs / Pools list.

4.	Choose the Save button to save your configuration changes.

5.	Choose the Close button.

Note   Configuration changes are apparent only to users who establish a connection after the configuration changes are saved. Users who were connected at the time the configuration changes were made will not be affected.


Editing A TN3270 LU Configuration

To edit a TN3270 LU configuration

1.	From the TN3270 Administration dialog box, choose the Config button.

2.	From the Configured LUs / Pools list, select one or more LUs or Pools.

3.	Choose the Edit button.

The Edit configuration for LUorPoolName dialog box appears.

Note   This dialog box now contains TN3270E support configuration and provides a place to specify Pool Type, Associated LU, Printer as Terminal Model, and IBM-3287-1 as Terminal Name String. These options are discussed below.

IP address, subnet mask, TN3270 sessions, terminal model, and terminal name strings, as shown in the following table, can all be edited if a single Pool has been selected. If a single LU is selected, all values except the subnet mask can be edited (a single LU can only be reserved for a single IP address). If multiple LUs and/or Pools are selected, then only the terminal model and terminal name strings can be edited.

Values to change	Single Pool	Single LU	Multiple LUs or Pools
IP address	yes	yes	no
Subnet Mask	yes	no	no
TN3270 Sessions	yes	yes	no
Terminal Model	yes	yes	yes
Terminal Name Strings	yes	yes	yes
These options are described below and apply only if you want to change the default value.

4.	Verify LU or Pool name and SNA Resource Information.

5.	Specify the IP address or IP name (or names) you want to assign to this LU or Pool.

IP name allows the user to specify that the client whose address resolves to that name can connect to the LU.

For more information on how this data is used, see Note on IP address comparison.

6.	Specify the Subnet Mask (or accept the default) if you are assigning these values to a Pool.

7.	Choose the Add button to add the IP Address/Subnet Mask values.

To delete an IP address, select the IP Address with the pointing device and choose the Remove button, or choose the Clear button to remove all IP Addresses from this LU or Pool.

8.	Select a pool type:

Generic

This is the default pool type. The LU or Pool will be assigned to a client that either does not specify a particular LU or Pool, or that requests this LU or Pool by name.

Specific

The LU or Pool configured as specific will only be assigned to clients that request this LU or Pool, and not to clients making generic requests.

Associated

Printer LUs can be marked as associated instead of generic or specific. To associate a printer LU with a terminal LU, check Printer under Terminal Model, check Associated as Pool Type, and choose the Associated LU from the drop-down list box.

Important   TN3270 clients can only access LUs that are configured as generic terminal LUs. TN3270E clients can access generic, specific, and associated LUs.

9.	Select the Associated LU if you are configuring a printer LU with Pool Type set as Associated. In this case the printer LU is partnered with one terminal LU. A client accesses that printer LU by sending in an "associate" request and giving the name of the terminal LU with which the printer LU is partnered.

10.	Specify the TN3270 Sessions number.

This is the number of TN3270 Sessions allowed for the selected LU or Pool. The number of TN3270 sessions must not exceed the Number of LUs listed under SNA Resource Information.

If you reduce the TN3270 Session limit to 0 (zero) TN3270 Service will not assign the LU or Pool.

11.	Select Terminal Model number or select Printer to configure a Printer LU or Pool.

TN3270 Service will default to IBM Terminal Model 2. Once a Terminal Model is selected, Terminal Name Strings are automatically assigned. You can deselect terminal types that do not apply to your network configuration by choosing the Advanced button, which displays a list of Terminal Name Strings, then clicking on the Terminal Name String you wish to deselect.

You can select more than one Terminal Model number and as many Terminal Name Strings as apply to your network configuration.

Note   The Terminal Name Strings selected must be compatible with the host logmode entry for the LU. Refer to the IBM Terminal Type Support section in Appendix D of the Microsoft SNA Server TN3270 Service for more information on host logmode entries.

12.	Choose the OK button.

The IP Address will be shown beside the LU or Pool name in the Configured LUs / Pools list. Multiple IP Addresses will be indicated by the first IP Address followed by three dots (such as 157.55.94.26   ...).

The next LU or Pool in the Configured LUs / Pools list will be highlighted.

13.	Choose the Save button to save configuration changes.

14.	Choose the OK button to close the dialog box.

Note   Configuration changes are apparent only to users who establish a connection after the configuration changes are saved. Users who were connected at the time the configuration changes were made will not be affected.


Zooming LUs

To view SNA Resource Information for an available LU or Pool

1.	From the TN3270 Administration dialog box, choose the Config button.

2.	From the Configured LUs / Pools list, select one LU or Pool.

3.	Choose the Zoom button.

The SNA Resource Information dialog box appears.

To make changes to SNA Resource Information, follow the instructions for Editing LUs.


Saving TN3270 Configuration

Choose the Save button in the Configure LUs for TN3270 dialog box to save the configuration after adding, deleting, or editing LUs or Pools. If you choose the OK button without first saving the configuration changes, you will be prompted to save changes.


Reopening TN3270 Configuration

Reopen allows you to revert to the last saved configuration. This is useful when making configuration changes that you are unsure of. If a mistake is made, you can choose Reopen and start again without closing and restarting TN3270 Service.

To reopen a TN3270 configuration

1.	From the TN3270 Administration dialog box, choose the Config button.

The Configure LUs for TN3270 dialog box appears.

2.	From Configuration Options area of the Configure LUs for TN3270 dialog box, choose the Reopen button.

You will be prompted to save changes.

Choose the Yes button to save the changes that have been made. This has the same effect as choosing the Save button.

Choose the No button to cancel the changes and revert to the last saved configuration. TN3270 Service will revert to last saved LU Definition information.


Backing Up TN3270 Configuration

Backup provides the ability to write the current configuration to a specific file as opposed to Save, which writes the current configuration to the default config file.

To backup a TN3270 configuration

1.	From the TN3270 Administration dialog box, choose the Config button.

2.	From Configuration Options, choose the Backup button.

3.	Type the name of the backup.

You may want to save your configuration to a separate directory. If you need to reinstall TN3270 Service later, your TN3270 directory will be replaced. This will delete all data within the TN3270 directory.

4.	Choose the OK button.

5.	Choose the Save button to save your configuration changes.


Restoring TN3270 Configuration

Restore allows you to retrieve a configuration from a backup file created by the Backup option.

To restore a TN3270 configuration

1.	From the TN3270 Administration dialog box, choose the Config button.

2.	From Configuration Options, choose the Restore button.

3.	Select the file you wish to restore.

4.	Choose the OK button.

The restored configuration will overwrite current LU Definition information.

5.	Choose the Save button to save your configuration changes.


Specifying Administrative Options

To specify Administrative Options

1.	From the TN3270 Administration dialog box, choose the Options button.

2.	Select Log Normal Audit Events and/or Use SNA Event Log.

This instructs TN3270 Service to log events in the SNA Server Event Log for diagnostic purposes.

3.	Specify time limits for Idle Timeout, Init Status Delay, Message Close Delay, and Refresh Cycle Time.

4.	Specify the use of Name Resolution.

Name Resolution should only be selected if you are running a domain name resolver. A domain name resolver catalogs IP addresses and corresponding network names of connected computers. The domain name resolver allows you to enter the name of a computer rather than the IP address when an IP address is required.

5.	Specify Inbound and Outbound RU size.

The minimum value for inbound or outbound RU size is 256 bytes. Adapting this value to the requirements of your TN3270 Service environment will ensure the most effective use of your computer memory.

6.	Choose the OK button to save your configuration changes.


Administering TN3270 Service

  Starting TN3270 Service

  Pausing TN3270 Service

  Continuing SNA Server

  Stopping TN3270 Service


Starting TN3270 Service

The TN3270 Service is invoked at system startup. However, you may need to start the TN3270 Service after you have paused or stopped it.

To start TN3270 Service from Control Panel

1.	In the Control Panel window, choose the Service icon.

A blank in the status column indicates that the service has stopped.

2.	In the Services dialog box, select TN3270.

3.	Choose the Start button.

4.	In the Services dialog box, choose the Close button.

To start TN3270 Service from an MS-DOS command prompt

Type net start tn3270


Pausing TN3270 Service

Pausing allows you to prevent new users from establishing a connection with TN3270 Service, without disconnecting current users. You can then view TN3270 Service Session Status and notify connected users to disconnect from TN3270 Service.

To pause TN3270 Service from Control Panel

1.	Select the Services option in Control Panel.

2.	In the Services dialog box, select TN3270.

3.	Choose the Pause button.

4.	Choose the Close button.

To pause TN3270 Service from an MSDOS command prompt

Type net pause tn3270


Continuing SNA Server

To continue TN3270 Service from Control Panel

1.	Select the Services option in Control Panel.

2.	In the Services dialog box, select TN3270.

3.	Choose the Continue button.

4.	Choose the Close button.

To continue TN3270 Service from an MSDOS command prompt

Type net continue tn3270


Stopping TN3270 Service

To stop TN3270 Service from Control Panel

1.	Use the Services option in Control Panel to pause TN3270 Service.

2.	Notify all connected users that they will be disconnected within a specified time period.

3.	After expiration of your warning period, use the Services option in Control Panel to stop TN3270 Service.

To stop TN3270 Service from an MSDOS command prompt

Type net stop tn3270

Once TN3270 Service has stopped, it can no longer be accessed. TN3270 Service can be restarted only on the local system.


Using TN3270 Trace Option

Trace files contain records of internal activities on the TN3270 Service. These files describe events leading up to a difficulty and the exact state of the system when the difficulty occurred. Trace files are created when TN3270 Service tracing is enabled. They are then stored in the TRACES subdirectory of the TN3270 Service root directory with the filename extension .TRC.

When gathering information about system difficulties, it is generally best to start with event log information. Event log information is generally more straightforward to interpret than tracing information. Contact your support technician regarding tracing information if event logs do not provide needed detail.

For information about event logs, see Using Event Logs, in your Microsoft SNA Server Administration Guide.

  Enabling TN3270 Trace Option

  Disabling TN3270 Service Trace Option


Enabling TN3270 Trace Option

To enable TN3270 Service trace option

1.	From the TN3270 Administration dialog box, choose the Trace button.

The Trace Options dialog box appears.

2.	Select Active option.

3.	Verify the Trace Directory.

4.	Enter the suggested Wrap Size.

5.	Choose OK.


Disabling TN3270 Service Trace Option

To disable TN3270 Service trace option

1.	From the TN3270 Administration dialog box, choose the Trace button.

The Trace Options dialog box appears.

2.	Deselect Active option.

3.	Choose OK.


Warning messages

  SNA Resource LUs and TN3270 Service sessions conflict.

  SNA Server configuration has been changed.

  TN3270 LU or Pool not found.

  No LUAs are defined.

  Invalid IP address / Subnet Mask specified.


SNA Resource LUs and TN3270 Service sessions conflict.

This dialog box is displayed when the number of LUs has changed for an SNA resource after the resource has been configured for TN3270 Service. The conflicting values are displayed. By choosing the default entry, you allow TN3270 Service to resolve the conflict.


SNA Server configuration has been changed.

This message is displayed when a TN3270 LU or LU Pool is not defined in the SNA Configuration. You can keep the TN3270 LU name or remove it.


TN3270 LU or Pool not found.

One of the TN3270 LUs or LU Pools that was configured for TN3270 Service was not found. The LU or Pool may have been deleted or changed in SNA Server.

Selecting Add will keep the LU or Pool configuration in TN3270 Service, but will reset the session count to 0. After restoring the LU or Pool in SNA Server, reset the session count in the TN3270 configuration to use this LU or Pool.

If you select Cancel, and then restore the LU or Pool in SNA Server, this warning should not reappear for this LU or Pool.


No LUAs are defined.

You must define LUA LUs and Pools in SNA Server before configuring LUs or Pools for TN3270 Service.


Invalid IP Address / Subnet Mask specified.

The results of a bitwise "AND" cannot equal 0.0.0.0.

This error message appears if you attempt to add an IP Address of 0.0.0.0 (the default value) to an LU or Pool. If you want to specify an IP Address, you must change the IP Address value from the default.


TN3270 services

TN3270 services allow TN3270 clients to communicate with remote computers such as IBM mainframes on an SNA network.


TN3270 clients

TN3270 clients are computers using 3270 terminal emulation services that communicate with a host mainframe through TN3270 Service.


Windows NT services

An application that is installed in a registry database maintained by the Service Control Manager.


Service Control Manager

A service control manager provides a unified and secure means of controlling services. Each computer running Windows NT has a service control manager process started by the system at system startup.


Client Address

A unique code identifying a TN3270 client that has established a connection with TN3270 Service. The Client address is either in the form of an IP address or an assigned network name.


LU Name

An alpha or numeric name assigned to a logical unit (LU).


State

A message that represents the current status of each TN client connected to TN3270 Service.


VTAM

Virtual Telecommunications Access Method. A set of IBM mainframe programs that control communications between mainframe applications and the terminals and computers that connect to the mainframe.


LU-LU

A session between two logical units (LUs) in an SNA network.


SSCP-LU

A session between system service control point (SSCP) and a logical unit (LU). The session enables the LU to request the SSCP to help initiate LU-LU session.


logmode entries

A subset of session parameters that are specified in a logmode table for communication with a logical unit.


Terminal Model

Terminal Model represents a group of Terminal Name Strings that maintain the same model number. Model 2, Model 3, Model 4, and Model 5 are supported by TN3270 Service.


Terminal Name Strings

IBM terminal names supported by the TN3270 Service. Each Terminal Name String corresponds to a unique logmode entry. The Terminal Name String is based on RFC 1340.


TN3270 Session

A period of communication between a TN3270 client and TN3270 Service that begins with the TN3270 client establishing a connection with TN3270 Service.


TN3270 Session Limit

Session Limit limits the total number of TN3270 sessions operational at one time. The TN3270 Service can be configured so that the number of sessions allowed for each Pool is limited to a number equal to or less than the number of configured LUs for the Pool.


Control Panel

Control Panel is a Windows NT application that provides you with a way to modify your system while working with Windows NT. The Control Panel icon is located in the Main window of your Windows NT computer.


TN3270 Service Session Status

Displays the status of TN3270 clients using TN3270 Service. To update the status of all sessions, choose the Refresh button.


Connected Users

TN3270 client users with displayed state of LU-LU.


Services

An application that is installed in a registry database maintained by the Service Control Manager.


Wrap Size

Wrap Size denotes the size limit of a trace file. If the Wrap Size is exceeded during a trace, the trace file either continues with a new trace file or is wrapped to the first trace file.


Trace Directory

Directory that contains files with detailed records of internal activities on the TN3270 (trace files). The default trace directory is drive:\TN3270root\TRACES.


Event log

The location in which TN3270 Service records events. Events may include attempts to establish connection, failures of system components, and other related information. Use the Windows NT Event Viewer to view event logs.


LU Definition

Logical Unit. A preset unit containing configuration information needed for a user, program, or downstream system to establish a session with a host or peer computer. TN3270 Service uses LUA LUs.


Pool Definition

A number of LUs, all of the same kind, that are made available as a group. TN3270 Service can get LU access as long as one of the pooled LUs is available. This provides for better access for multiple users. TN3270 uses LUA LU pools.


IP address

A 32-bit internet address assigned to a computer for the purpose of participating in a TCP/IP internet. This address specifies the network connection and consists of both a network ID and a host ID. The IP address of a computer running Windows or Windows NT can be determined by use of the command ipconfig at the command prompt.


Subnet Mask

A 32-bit value used to restrict access to an SNA LU resource. See note on IP address comparison for more information.


Note on IP address comparison

The IP Address must be changed from the default value of 0.0.0.0 if you want to assign a specific IP address. If you try to add the default IP address with the default Subnet Mask value, you will receive an error message indicating an Invalid IP Address/Subnet Mask.

The IP address of an incoming connect is compared to each of the available LUs or pools in turn. Each resource has an associated list of IP address patterns and Subnet masks. The IP address from incoming connect is masked (bitwise AND) by the resources Subnet mask, then compared to the resources IP address pattern masked by the resources Subnet mask. If result is equal, the connect is allocated to this resource.