23 - Implementing SNA Server

• How to create and configure logical units (LUs) - Learn what the different LU types actually do. Then follow a series of detailed, step-by-step procedures to create and configure your 3270, APPC, LUA, and downstream LUs individually or several at one time.

• How to group LUs into pools - Learn how to use SNA Server Admin and the LU Pools window to create and configure different types of LU pools, assign all types of configured LUs to the pools, and move LUs between pools.

• How to assign LUs and LU pools to users and groups - Learn how to use SNA Server Admin and the Users and Groups window to create users and groups, configure properties for the users and groups, and grant security permissions to the users and groups so that they can access assigned LUs, LU pools, and other SNA network resources.

• How to configure downstream connections and associate LUs and LU pools with them. - Focus here is on establishing the remote connection leg to the SNA Server and then interfacing that leg with SNA Server-to-host connections to gain access to host resources from remote locations.

The preceding chapter detailed the actions necessary to build the SNA Server and establish the connections between the SNA Server and the host mainframe or AS/400 system. This chapter explores the concepts and procedures necessary to "implement" the SNA Server, or in other words, to configure the logical units (LUs) and downstream connections.

When you have completed the procedures in this chapter for your particular installation, your SNA Server should be capable of supporting SNA network client communications with the host system.

Configuring the LUs

• 3270 LU. Provides access to IBM mainframe environments using 3270 emulation.

• Advanced Program-to-Program Communications (APPC) LU. Provides access to AS/400 environments using 5250 emulation. Allows transaction programs (TPs) on peer systems to communicate with each other over the SNA network. APPC LUs use LU 6.2 protocols.

• Logical Unit Application (LUA) LU. Provides access to a connection by LUA applications. LUA applications, which allow communications between a PC and an IBM host, use LU 0, LU 1, LU 2, or LU 3 protocols.

• Downstream LU. Allows an SNA Server to support communications between an IBM host and clients that do not use the SNA Server client/server interface (Macintosh systems, IBM Communications Manager/2 systems, and so on).

The following sections contain step-by-step procedures for creating and configuring each of these LU types.

Creating and Configuring 3270 LUs

Individual 3270 LUs

To create and configure 3270 LUs individually, follow these steps:

1. In the Servers and Connections window, click any item to make the Servers and Connections window the active window on the SNA Server Admin screen. Then click the connection to which the LU will be assigned.

2. In the SNA Server Admin menu bar, choose Services, Assign LUs. The Insert LU dialog box appears, as shown in figure 23.1.

   Fig. 23.1 - The Insert LU dialog box showing the New Logical Unit options and the default selection.

3. Click 3270 in the New Logical Unit area of the dialog box.

4. Click OK to clear the Insert LU dialog box and display the New 3270 LU Properties dialog box shown in figure 23.2.

   Fig. 23.2 - The New 3270 LU Properties dialog box is used to define the LU number and name along with a few other parameters.

5. In the LU Number box, enter a number for this LU. Although valid numbers range from 1 through 254, SNA conventions dictate that LU numbers always start with 2, not 1. Therefore, the permissible values are really 2 through 254. This number must correspond to the VTAM SysGen parameter, LOCADDR, in the VTAM generator on the host computer. Coordinate with the SNA host administrator for the number to use and enter that number here. If the number you entered has already been assigned to an LU, a message box appears telling you to enter a different number because duplicate LU numbers are not permitted.

6. Enter a unique name for this LU. This name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $).

7. No action is required in the Connection box. It simply displays the connection for the LU you are creating and configuring.

8. The Comment box is optional. If you do decide to enter a comment, you can enter up to 25 characters of free-form text.

9. In the LU Type area, click the radio button next to the appropriate choice. If the LU will be used for terminal emulation, click Display. This is the default selection. If the LU will be used for printing host system data on a local or network printer, click Printer.

10. In the Display Model area, either accept Model 2 as the default or click the radio button next to the desired display model. The model determines the number of lines and the number of characters per line to be displayed. Some emulators are only capable of emulating certain display models, so you should reference your emulator documentation to determine the display model constraints of your specific emulator.

11. The Model Can Be Overridden check box is, by default, marked (contains an X) to indicate that the display model can be overridden by using the 3270 terminal emulation program. If you do not want to be able to override the display model, unmark the check box (remove the X) by clicking on it while it contains the X.

12. Click OK to exit the dialog box and accept the settings or click Cancel to exit the dialog box without accepting the settings. The Servers and Connections window then appears, reflecting the 3270 LUs just configured.

Range of 3270 LUs

Perform these steps to create and configure a range of consecutively numbered 3270 LUs:

1. In the Servers and Connections window, click any item to make the Servers and Connections window the active window on the SNA Server Admin screen. Then click the connection to which the LU will be assigned.

2. In the SNA Server Admin menu bar, choose Services, Assign LUs. The Insert LU dialog box appears (refer to fig. 23.1).

3. Click 3270 in the New Logical Unit area of the dialog box.

4. Click the Range of LUs check box (to mark it with an X) to configure several consecutively numbered LUs at one time. When you click OK in the Insert LU dialog box with the Range of LUs check box marked, the Add LU Range dialog box appears as displayed in figure 23.3.

   Fig. 23.3 - The Add LU Range dialog box is used to define the LU range.

5. In the Base LU Name box, enter a unique name for the LU range. The LUs in the range will have names composed of this Base LU Name and an extension number, and each name can contain a maximum of eight characters (alphanumeric and special characters @, #, and $). Therefore, the permissible length of the Base LU Name really depends on the number of digits (1, 2, or 3) you will be using for the extension number. For example, if you plan to use two-digit extension numbers (to cover up to 99 individual LUs), the Base LU Name must be limited to six characters. Keep this in mind when entering the Base LU Name.

6. In the First LU Number box, enter a number for the first LU. Although valid numbers range from 1 through 254, SNA conventions dictate that LU numbers always start with 2, not 1. Therefore, the permissible values are really 2 through 254. This number must correspond to the VTAM SysGen parameter, LOCADDR, in the VTAM generator on the host computer. Coordinate with the SNA host administrator for the number to use. If the number you entered has already been assigned to an LU, a message box appears telling you to enter a different number because duplicate LU numbers are not permitted.

7. In the Number of LUs box, enter the number of LUs you want in the range. The SNA Server numbers them sequentially from the first number specified.

   
   Even though the host administrator may instruct you to use LU numbers that are not consecutive, you can still create a range of sequential LU numbers and then modify the individual LU numbers after they have been created.
   

8. No action is required in the Selected LU Range box. It simply displays the range of LU names after you have defined the range.

9. If you do not want to modify the extension number format, go to step 13. Otherwise, click Options to modify the extension number format. This causes the Add LU Range dialog box to be expanded to include the Extension Numbering Format area as reflected in figure 23.4.

   Fig. 23.4 - The Add LU Range dialog box with the Extension Numbering Format displayed.

10. The First Extension box displays the default first extension, which is the First LU Number entry in the upper portion of the Add LU Range dialog box. Either accept this default or enter a new first extension number. If the Base LU Name is six characters, the First Extension number cannot be greater than two digits (01-99) so as not to violate the maximum length permitted for the LU name. The permissible decimal range of values is 0 through 999, and the permissible hexadecimal range of values is 0 through FFF.

11. In the Number System area, click the desired radio button to specify the numbering system to be used for the extension numbers. The default is Decimal. This selection does not affect LU numbers.

12. The Add Leading Zeros check box is, by default, marked (an X is present) to indicate that the option is active. To turn off the option, simply click the check box containing the X to clear the mark. Leading zeros ensure that LU names display in the proper sequence.

13. Click OK to clear the Add LU Range dialog box and display the 3270 LU Range Properties dialog box shown in figure 23.5.

    Fig. 23.5 - The 3270 LU Range Properties dialog box displays the range of 3270 LU numbers and names just created.

14. No action is required in the LU Numbers box. It simply displays the range of LU numbers you just created. LU numbers cannot be modified in this dialog box.

15. No action is required in the LU Names box. It simply displays the range of LU names you just created. LU names cannot be modified in this dialog box.

16. No action is required in the Connection box. It simply displays the connection for the LU range you just created. Connections cannot be modified in this dialog box.

17. The Comment box is optional. If you do decide to enter a comment, you can enter up to 25 characters of free-form text.

18. In the LU Type area, click the radio button next to the appropriate choice. If the LUs will be used for terminal emulation, click the Display radio button. This is the default selection. If the LUs will be used for printing host system data on a local or network printer, click the Printer radio button.

19. In the Display Model area, either accept Model 2 as the default or click the radio button next to the desired display model. The model determines the number of lines and the number of characters per line to be displayed. Some emulators are only capable of emulating specific display models, so you should reference your emulator documentation to determine the display model constraints of your specific emulator.

20. The Model Can Be Overridden check box is, by default, marked (contains an X) to indicate that the display model can be overridden by using the 3270 terminal emulation program. If you do not want to be able to override the display model, unmark the check box (remove the X) by clicking it while it contains the X.

21. Click OK to exit the dialog box and accept the settings or click Cancel to exit the dialog box without accepting the settings. The Servers and Connections window the appears, reflecting the 3270 LUs just configured.

Creating and Configuring APPC LUs

Local APPC LUs

To assign and configure a local APPC LU, follow these steps:

1. In the Servers and Connections window, click any item to make the Servers and Connections window the active window on the SNA Server Admin screen. Then click the SNA Server to which the local LU will be assigned.

2. In the SNA Server Admin menu, choose Services, Assign LUs to display the Insert LU dialog box (refer to fig. 23.1).

   
   When the Insert LU dialog box appears, the APPC (Local) radio button in the New Logical Unit area of the dialog box will already be selected. All other New Logical Unit options will be grayed out and unavailable.
   

3. Click OK to clear the Insert LU dialog box and display the New APPC LU Properties dialog box shown in figure 23.6.

   Fig. 23.6 - The New APPC LU Properties dialog box is used to establish parameters for a new local APPC LU.

4. In the LU 6.2 Type box, select either Independent or Dependent, as appropriate. Independent APPC LUs can communicate directly with a peer system and can support multiple parallel sessions. Dependent APPC LUs require support from the local host system to communicate with a remote peer, and they can only support a single session for each LU.

   
   If the local LU will be used to communicate with a remote LU over a Distributed Function Terminal (DFT) connection, the local LU 6.2 Type must be Dependent.
   

5. In the LU Alias box, enter a unique name for this LU that identifies it to the local TPs. This name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $). Even though this alias needs to be unique on the server, the alias can be the same as the LU name.

6. In the Network Name box, enter the network name identifying the SNA network. This name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $). For independent LUs, this network name is required. For dependent LUs, the network name is optional. Even though the network name may be optional, you would be wise to assign one anyway because it provides an easy way to identify the network when reviewing monitoring and diagnostic tools such as the Windows NT Event Viewer. The SNA host or peer system administrator should advise you as to what the name should be because it needs to match the NETID parameter in the VTAM Start command for host systems operating under VTAM. The default network name is the network name for the SNA Server, or if no SNA Server network name has been specified, the default is APPN.

   
   If this server will be used to communicate with numerous hosts over several different connections, the network name should be the same as the subarea of the host with which this LU will communicate.
   

7. In the LU Name box, enter a unique name identifying this LU. This name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $). For independent LUs, this name is required because it identifies this LU to the other network components. For dependent LUs, the name is optional. Even though the name may be optional, you would be wise to assign one anyway because it provides an easy way to identify the LU when reviewing monitoring and diagnostic tools such as the Windows NT Event Viewer. This LU name can match the LU alias for this LU.

8. The LU Number box is only available if the LU 6.2 Type is dependent. In this case, enter a number in the range 1 through 254 to identify the dependent LU. The number must be unique on the connection. Coordinate with the host system administrator because this number must match the LOCADDR parameter in the VTAM LU definition or in the NCP Gen. If the LU 6.2 Type is independent, the LU Number box will be grayed out.

   
   The permissible range of numbers is 2 through 254 if the local dependent LU will be partnered with a remote LU using a DFT connection.
   

9. In the Comment box, enter a comment up to 25 characters long. Comments are optional, so if you desire, you can leave this box blank.

10. Local and remote LUs work together in pairs and are said to be partnered. This partnering can be automatically performed, or it can be manually controlled by using only remote LUs and modes you specifically select. It all depends on whether the Enable Automatic Partnering check box is marked or unmarked. To allow the SNA Server to automatically partner the local APPC LU with every remote LU and mode designated as an automatic partner, accept the default setting (the check box is marked with an X). If you do not want the local APPC LU to be automatically partnered with every other remote LU and mode so designated, click the marked check box to unmark it (removes the X).

    
    Whenever a new LU or mode is created with the Enable Automatic Partnering check box marked (automatic partnering is enabled), SNA Server uses all the existing LUs and modes that have automatic partnering enabled to create as many LU pairs as possible. Each LU pair has to consist of a local LU, a remote LU, and a mode. Disabling automatic partnering for a specific LU pair component does not affect pairings that have already been made, but it does influence the creation of future pairings.
    

11. When an invoking TP requests an LU session from the SNA Server, the SNA Server first tries to satisfy the request with the Default Local APPC LU specifically assigned to the user or group controlling the invoking TP. If this is not possible, SNA Server then tries to satisfy the request by using an available LU in the Default Outgoing Local APPC LUs pool. You can make a local LU a member of this pool by clicking the Member of Default Outgoing Local APPC LU Pool check box to mark it (an X appears in the check box). If you do not want this local LU to be a member of the pool, click the check box when it is marked (contains an X) to unmark it (removes the X).

12. SNA Server has the flexibility of accepting incoming requests for LU sessions from many different remote LUs that have not been defined on the SNA Server. By clicking the Implicit Incoming Remote LU drop-down list box to display the list of remote LUs and then selecting a remote APPC LU that defines the properties for SNA Server to use, this flexibility is enabled. Then when an unknown remote LU requests a session with a recognized local LU, SNA Server uses the properties defined in the implicit incoming remote LU to control the session. If you do not want SNA Server to accept session requests from unknown remote LUs, then select None from the drop-down list.

13. In the Timeout for Starting Invokable TPs box, either accept the default of 60 or enter a new value from 1 through 3600 to represent the maximum number of seconds the SNA Server should wait for the invokable TP to respond to a start request from the invoking TP. Allow sufficient time (usually greater than 60 seconds) in those cases where the invokable TP will be started manually by the operator.

14. If you have not previously configured a remote APPC LU with which to partner this local APPC LU, or if you simply do not want to partner LUs at this time, go to step 32. Otherwise, click Partners and continue with step 15.

15. When you click Partners in the New APPC LU Properties dialog box, the LU 6.2 Partner LUs dialog box is displayed. Any LU pairings that have already been created using this local APPC LU are reflected in the Partner LU column, as shown in figure 23.7.

    Fig. 23.7 - The LU 6.2 Partner LUs dialog box showing that the LU named REMOTE1 has already been paired (partnered) with the LOCAL LU.

16. If the mode you need already exists, go to step 29. Otherwise, click Modes to display the APPC Mode Properties dialog box so that you can create the new mode you need (see fig. 23.8).

    Fig. 23.8 - The APPC Mode Properties dialog box appears when the Modes button in the LU 6.2 Partner LUs dialog box is clicked.

17. In the Mode Name box, enter a unique name for this mode. This name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $).

18. In the Comment box, enter a comment up to 25 characters long. Comments are optional, so if you want, you can leave this box blank.

19. In the Parallel Session Limit box, either accept the default value of 1 or enter a new value from 1 through 1024 to represent the maximum number of sessions allowed with this mode. If two or more sessions are allowed, they will be conducted in parallel; that is, multiple concurrent sessions will be conducted between an APPC LU pair in which two TPs perform multiple operations simultaneously.

    
    Because dependent local APPC LUs cannot support parallel sessions, you must specify "1" if the local APPC LU to be used with this mode has been defined as dependent.
    

20. In the Minimum Contention Winner Limit box, either accept the default of 0 or enter a new value from 0 through the Parallel Session Limit defined earlier. This value represents the minimum number of sessions in which the local LU must be able to initiate communications without first obtaining permission from the partnered LU (that is, be the contention winner).

21. In the Partner Min Contention Winner Limit box, either accept the default of 0 or enter a new value from 0 through the Parallel Session Limit defined earlier. This value represents the minimum number of sessions in which the partner LU must be able to initiate communications without first obtaining permission from the local LU (that is, be the contention winner).

    
    The sum of the values used for the Minimum Contention Winner Limit and the Partner Min Contention Winner Limit cannot be greater than the value used for the Parallel Session Limit.
    

22. In the Automatic Activation Limit box, enter a value from 0 through the Minimum Contention Winner Limit value defined earlier. This value represents the maximum number of contention winner sessions that can be activated for the local LU whenever the connection for this mode is started.

23. The Enable Automatic Partnering check box allows the SNA Server to automatically partner this mode with every local and remote LU designated for automatic partnering when the check box is marked with an X (the default setting). If you do not want this mode to be automatically partnered with every other local and remote LU so designated, click the marked check box to unmark it (removes the X).

24. The High Priority Mode check box is, by default, marked (contains an X) to indicate this mode should be given communications preference over other low-priority modes. If you want this mode to have a low priority, unmark the check box (remove the X) by clicking it while it contains the X.

25. In the Pacing Send Count box, either accept the default of 4 or enter a new value from 0 through 63 to represent the maximum number of frames the local LU can send before it receives an SNA pacing response from the partner LU. If you enter 0 in the box, the local LU can send an unlimited number of frames without receiving a response.

26. In the Pacing Receive Count box, either accept the default of 4 or enter a new value from 0 through 63 to represent the maximum number of frames the local LU can receive before it sends an SNA pacing response to the partner LU. If you enter 0 in the box, the local LU can receive an unlimited number of frames without sending a response.

27. In the Max Send RU Size box, either accept the default of 1024 or enter a new value from 256 through 16384 to represent the maximum size for RUs sent by the TP(s) on the local system.

28. In the Max Receive RU Size box, either accept the default of 1024 or enter a new value from 256 through 16384 to represent the maximum size for RUs received by the TP(s) on the remote system.

29. Click Add to add the new mode just defined. Then click Close to clear the APPC Mode Properties dialog box and redisplay the LU 6.2 Partner LUs dialog box. If you do not need to add a partner to the list of partners for this LU, skip to step 31.

    
    The APPC Mode Properties dialog box can also be used to change mode properties and to delete a specific mode all together. To delete a mode in the APPC Mode Properties dialog box, select the mode name in the Mode Name list box and then click Delete. Likewise, to modify the properties of an existing mode in the APPC Mode Properties dialog box, select the mode name from the Mode Name list box to display the existing properties of the selected mode. Modify these properties as necessary and then click Change.
    

30. To add a partner to the list of partners for this LU, click Add in the LU 6.2 Partner LUs dialog box. When the Add APPC LU Partner dialog box appears, select the partner LU and mode for the pairing and click OK (refer to fig. 23.7). If you do not need to delete a partner from the list of partners for this LU, skip to step 32.

31. If you want to delete a partner LU from the list of partners, simply highlight the partner LU to be deleted in the LU 6.2 Partner LUs dialog box, and then click Delete. If you do not need to associate an existing mode to an LU pairing, skip to step 33.

32. To associate an existing mode with an LU pairing, click Add in the LU 6.2 Partner LUs dialog box. When the Add APPC LU Partner dialog box appears, select the mode for the pairing and click OK.

33. Click Close in the LU 6.2 Partner LUs dialog box to clear the dialog box and redisplay the New APPC LU Properties dialog box. Then complete the configuration of the local APPC LU by taking one of the following actions:
    • If you want to save the configuration parameters entered and exit from the New APPC LU Properties dialog box, click OK. The Servers and Connections window appears, reflecting the new local APPC LU just configured.

    • If you want to exit from the New APPC LU Properties dialog box without saving the configuration settings, simply click Cancel. The Servers and Connections window appears.

Remote APPC LUs

To assign and configure a remote APPC LU, follow these steps:

1. In the Servers and Connections window, click any item to make the Servers and Connections window the active window on the SNA Server Admin screen. Then click the connection to which the remote APPC LU will be assigned.

2. In the SNA Server Admin menu bar, choose Services, Assign LUs to display the Insert LU dialog box (refer to fig. 23.1).

3. Click APPC (Remote) in the New Logical Unit area of the Insert LU dialog box.

4. Click OK to clear the Insert LU dialog box and display the New APPC Remote LU Properties dialog box shown in figure 23.9. Note that the Supports Parallel Sessions check box will be grayed out and unavailable if this new APPC remote LU is being created for a DFT connection.

   Fig. 23.9 - The New APPC Remote LU Properties dialog box is used to establish parameters for a new remote APPC LU.

5. In the LU Alias box, enter a unique name for this LU that identifies it to the local TPs. This name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $). Even though this alias needs to be unique on both the connection and the server, the LU Alias can be the same as the LU Name for the LU.

6. In the Network Name box, enter a unique network name identifying the SNA network. This name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $). The SNA host or peer system administrator should advise you as to what the name should be because it needs to match the NETID parameter in the VTAM Start command for host systems operating under VTAM. The default network name is the network name for the SNA Server, or if no SNA Server network name has been specified, the default is APPN.

7. In the LU Name box, enter a unique name identifying this LU. This name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $). For a remote LU partnered with an independent local APPC LU, this name is required because it identifies the remote LU to the other SNA network components. For a remote LU partnered with a dependent local APPC LU, the name is optional. Even though the name may be optional, you would be wise to assign one anyway because it provides an easy way to identify the remote LU when reviewing monitoring and diagnostic tools such as the Windows NT Event Viewer. This LU Name can match the LU Alias for this LU.

8. The Uninterpreted LU Name box must contain the remote LU name (as defined on the remote system services control point, or SSCP) if the remote LU will be partnered with a dependent local APPC LU. This name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $). This Uninterpreted LU Name can match the LU Alias and LU Name for this LU.

9. In the Comment box, enter a comment up to 25 characters long. Comments are optional, so if you want, you can leave this box blank.

10. The Supports Parallel Sessions check box is used to specify whether this remote LU will be used to support multiple concurrent (parallel) sessions when paired with an independent local APPC LU. To enable parallel session support, click the unmarked check box to mark it (with an X). If you do not want to enable parallel session support, click the marked check box to unmark it (removes the X). If the remote LU is partnered with a dependent local APPC LU, parallel session support is not possible, and the check box must remain unmarked (parallel session support is disabled).

    
    If a remote LU is to support parallel sessions, you must use it with a mode whose parallel session limit value is greater than 1.
    

11. Local and remote LUs work together in pairs and are said to be partnered. This partnering can be automatically performed, or it can be manually controlled by using only local LUs and modes you specifically select. It all depends on whether the Enable Automatic Partnering check box is marked or unmarked. To allow the SNA Server to automatically partner the remote APPC LU with every local LU and mode designated as an automatic partner, accept the default setting (the check box is marked with an X). If you do not want the remote APPC LU to be automatically partnered with every other local LU and mode so designated, click the marked check box to unmark it (removes the X).

    
    Whenever a new LU or mode is created with the Enable Automatic Partnering check box marked (automatic partnering is enabled), SNA Server uses all the existing LUs and modes that have automatic partnering enabled to create as many LU pairs as possible. Each LU pair has to consist of a local LU, a remote LU, and a mode. Disabling automatic partnering for a specific LU pair component does not affect pairings that have already been made, but it will influence the creation of future pairings.
    

12. SNA Server has the flexibility of accepting incoming requests for LU sessions from many different remote LUs whose mode names have not been defined on the SNA Server. By clicking the Implicit Incoming Mode drop-down list box to display the list of modes and then selecting a mode that defines the properties for SNA Server to use, this flexibility is enabled. Then when an LU session request is made, but the named mode is not recognized by the SNA Server, the SNA Server will use the properties defined in the implicit incoming mode. If this remote APPC LU has been earlier designated as an implicit incoming remote LU for a local APPC, then a mode must be selected from the Implicit Incoming Mode drop-down list box. Otherwise, you may select None from the drop-down list.

13. If you have not previously configured a local APPC LU with which to partner this remote APPC LU, or if you simply do not want to partner LUs at this time, go to step 31. Otherwise, click Partners and continue with step 14.

14. When you click Partners in the New APPC Remote LU Properties dialog box, the LU 6.2 Partner LUs are displayed. Any LU pairings that have already been created using this remote APPC LU are also reflected in the Partner LU column (refer to fig. 23.7).

15. pertains to a local APPC LU being partnered with another LU. The LU 6.2 Partner LUs dialog box for a remote APPC LU looks the same except for the LU 6.2 Partners For name. In figure 23.7, the name is for a local APPC LU instead of for a remote APPC LU.

16. If the mode you need already exists, go to step 28. Otherwise, click Modes to display the APPC Mode Properties dialog box so that you can create the new mode you need (refer to fig. 23.8).

17. In the Mode Name box, enter a unique name for this mode. This name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $).

18. In the Comment box, enter a comment up to 25 characters long. Comments are optional, so if you want, you can leave this box blank.

19. In the Parallel Session Limit box, either accept the default value of 1 or enter a new value from 1 through 1024 to represent the maximum number of sessions allowed with this mode. If two or more sessions are allowed, they will be conducted in parallel; that is, multiple concurrent sessions will be conducted between an APPC LU pair in which two TPs perform multiple operations simultaneously.

    
    Because dependent local APPC LUs cannot support parallel sessions, you must specify "1" if the local APPC LU to be used with this mode has been defined as dependent.
    

20. In the Minimum Contention Winner Limit box, either accept the default of 0 or enter a new value from 0 through the Parallel Session Limit defined earlier. This value represents the minimum number of sessions in which the local LU must be able to initiate communications without first obtaining permission from the partnered LU (that is, be the contention winner).

21. In the Partner Min Contention Winner Limit box, either accept the default of 0 or enter a new value from 0 through the Parallel Session Limit defined earlier. This value represents the minimum number of sessions in which the partner LU must be able to initiate communications without first obtaining permission from the local LU (that is, be the contention winner).

    
    The sum of the values used for the Minimum Contention Winner Limit and the Partner Min Contention Winner Limit cannot be greater than the value used for the Parallel Session Limit.
    

22. In the Automatic Activation Limit box, enter a value from 0 through the Minimum Contention Winner Limit value defined earlier. This value represents the maximum number of contention winner sessions that can be activated for the local LU whenever the connection for this mode is started.

23. The Enable Automatic Partnering check box allows the SNA Server to automatically partner this mode with every local and remote LU designated for automatic partnering when the check box is marked with an X (the default setting). If you do not want this mode to be automatically partnered with every other local and remote LU so designated, click the marked check box to unmark it (removes the X).

24. The High Priority Mode check box is, by default, marked (contains an X) to indicate that this mode should be given communications preference over other low-priority modes. If you want this mode to have a low priority, unmark the check box (remove the X) by clicking it while it contains the X.

25. In the Pacing Send Count box, either accept the default of 4 or enter a new value from 0 through 63 to represent the maximum number of frames the local LU can send before it receives an SNA pacing response from the partner LU. If you enter 0 in the box, the local LU can send an unlimited number of frames without receiving a response.

26. In the Pacing Receive Count box, either accept the default of 4 or enter a new value from 0 through 63 to represent the maximum number of frames the local LU can receive before it sends an SNA pacing response to the partner LU. If you enter 0 in the box, the local LU can receive an unlimited number of frames without sending a response.

27. In the Max Send RU Size box, either accept the default of 1024 or enter a new value from 256 through 16384 to represent the maximum size for RUs sent by the TP(s) on the local system.

28. In the Max Receive RU Size box, either accept the default of 1024 or enter a new value from 256 through 16384 to represent the maximum size for RUs received by the TP(s) on the remote system.

29. Click Add to add the new mode just defined. Then click Close to clear the APPC Mode Properties dialog box and redisplay the LU 6.2 Partner LUs dialog box. If you do not need to add a partner to the list of partners for this LU, skip to step 30.

    
    The APPC Mode Properties dialog box can also be used to change mode properties and to delete a specific mode all together. To delete a mode in the APPC Mode Properties dialog box, select the mode name in the Mode Name list box, and then click Delete. Likewise, to modify the properties of an existing mode in the APPC Mode Properties dialog box, select the mode name from the Mode Name list box to display the existing properties of the selected mode. Modify these properties as necessary and then click Change.
    

30. To add a partner to the list of partners for this LU, click Add in the LU 6.2 Partner LUs dialog box (refer to fig. 23.7). When the Add APPC LU Partner dialog box appears, select the partner LU and mode for the pairing and click OK. If you do not need to delete a partner from the list of partners for this LU, skip to step 31.

31. If you want to delete a partner LU from the list of partners, simply highlight the partner LU to be deleted in the LU 6.2 Partner LUs dialog box and then click Delete. If you do not need to associate an existing mode to an LU pairing, skip to step 32.

32. To associate an existing mode with an LU pairing, click Add in the LU 6.2 Partner LUs dialog box. When the Add APPC LU Partner dialog box appears, select the mode for the pairing and click OK.

33. Click Close in the LU 6.2 Partner LUs dialog box to clear the dialog box and redisplay the New APPC Remote LU Properties dialog box. If you do not need to configure session security for remote LUs, skip to step 38.

34. To configure remote LU session security, click Security in the New APPC Remote LU Properties dialog box to display the APPC Session Security dialog box shown in figure 23.10.

    Fig. 23.10 - The APPC Session Security dialog box with the default session level security option selected.

35. By default, the No Session-Level Security option is enabled, meaning that session-level security has been turned off. Session-level security cannot be activated unless the security keys for the APPC session and the remote LU match.

36. Click the Security Key in Hex radio button if you want the security key to be in hexadecimal, and then enter a 16-digit hexadecimal number for the security key.

37. Click the Security Key in Characters radio button if you want the security key to be in characters, and then enter an eight-character string (alphanumeric and special characters @, #, period, and $) for the security key.

38. Either click OK to accept the security settings and exit the APPC Session Security dialog box, or click Cancel to exit the dialog box without saving the security settings. The New APPC Remote LU Properties dialog box appears.

39. Complete the configuration of the remote APPC LU by taking one of the following actions:
    • If you want to save the configuration parameters entered and exit from the New APPC Remote LU Properties dialog box, click OK. The Servers and Connections window appears, reflecting the new APPC remote LU just configured.

    • If you want to exit from the New APPC Remote LU Properties dialog box without saving the configuration settings, simply click Cancel. The Servers and Connections window appears.

Creating and Configuring LUA LUs

Individual LUA LUs

To create and configure LUA LUs individually, follow these steps:

1. In the Servers and Connections window, click any item to make the Servers and Connections window the active window on the SNA Server Admin screen. Then click the connection to which the LU will be assigned.

2. In the SNA Server Admin menu, choose Services, Assign LUs to display the Insert LU dialog box (refer to fig. 23.1).

3. Click LUA in the New Logical Unit area of the dialog box.

4. Click OK to clear the Insert LU dialog box and display the New LUA LU Properties dialog box (see fig. 23.11).

   Fig. 23.11 - The New LUA LU Properties dialog box is used to assign a new LUA LU number and name.

5. In the LU Number box, enter a number for this LU. Although valid numbers range from 1 through 254, SNA conventions dictate that LU numbers always start with 2, not 1. Therefore, the permissible values are really 2 through 254. This number must correspond to the VTAM SysGen parameter, LOCADDR, in the VTAM generator on the host computer. Coordinate with the SNA host administrator for the number to use and enter that number here. If the number you entered has already been assigned to an LU, a message box appears telling you to enter a different number because duplicate LU numbers are not permitted.

   
   LUA LUs for DFT connections do not require an LU number, but instead use a Port Number (the DFT adapter number with permissible values from 1 through 4) and an LT number (the Logical Terminal number configured at the 3174 for this coaxial cable with permissible values from 1 through 5.).
   

6. Enter a unique name for this LU. This name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $).

7. No action is required in the Connection box. It simply displays the connection for the LU you are creating and configuring.

8. If this LU has already been assigned to a LU Pool, the name of that pool appears in the Pool box. If it has not yet been assigned to a pool, None appears in this box.

9. The Comment box is optional. If you do decide to enter a comment, you can enter up to 25 characters of free-form text.

10. The High Priority LU check box is, by default, marked (contains an X) to indicate this LU has priority over other low-priority LUs. If this LU belongs to an LU Pool, then the LU Pool priority takes precedence, and this option will be grayed out. If you want this LU to have a low priority, unmark the check box (remove the X) by clicking it while it contains the X.

11. Click OK to exit the dialog box and accept the settings, or click Cancel to exit the dialog box without accepting the settings. The Servers and Connections window appears, reflecting the new LUA LU just configured.

Range of LUA LUs

Follow these steps to create and configure a range of consecutively numbered LUA LUs:

It is not possible to create and configure a range of LUA LUs for DFT connections. They must be configured one at a time.

1. In the Servers and Connections window, click any item to make the Servers and Connections window the active window on the SNA Server Admin screen. Then click the connection to which the LU(s) will be assigned.

2. In the SNA Server Admin menu bar, choose Services, Assign LUs to display the Insert LU dialog box (refer to fig. 23.1).

3. Click LUA in the New Logical Unit area of the dialog box.

4. Click Range of LUs (to mark it with an X) to configure several consecutively numbered LUs at one time. (To unmark or clear the X from the Range of LUs check box, click the check box when it is marked.) When you click OK in the Insert LU dialog box with the Range of LUs check box marked, the Add LU Range dialog box appears (refer to fig. 23.3).

5. In the Base LU Name box, enter a unique name for the LU range. The LUs in the range will have names composed of this base LU name and an extension number, and each name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $). Therefore, the permissible length of the base LU name really depends on the number of digits (1, 2, or 3) you will be using for the extension number. For example, if you plan to use two-digit extension numbers (to cover up to 99 individual LUs), the base LU name must be limited to six characters. Keep this in mind when entering the Base LU Name.

6. In the First LU Number box, enter a number for the first LU. Although valid numbers will range from 1 through 254, SNA conventions dictate that LU numbers always start with 2, not 1. Therefore, the permissible values are really 2 through 254. This number must correspond to the VTAM SysGen parameter, LOCADDR, in the VTAM generator on the host computer. Coordinate with the SNA host administrator for the number to use. If the number you entered has already been assigned to an LU, a message box appears telling you to enter a different number because duplicate LU numbers are not permitted.

7. In the Number of LUs box, enter the number of LUs you want in the range. The SNA Server numbers them sequentially from the first number specified.

   
   Even though the host administrator may instruct you to use LU numbers that are not consecutive, you can still create a range of sequential LU numbers and then modify the individual LU numbers after they have been created.
   

8. No action is required in the Selected LU Range box. It simply displays the range of LU names after you have defined the range.

9. If you do not want to modify the extension number format, go to step 13. Otherwise, click Options to modify the extension number format. This causes the Add LU Range dialog box to be expanded to include the Extension Numbering Format area (refer to fig. 23.4).

10. The First Extension box displays the default first extension, which is the First LU Number entry in the upper portion of the Add LU Range dialog box. Either accept this default or enter a new first extension number. If the Base LU Name is six characters, the First Extension number cannot be greater than two digits (01-99) so as not to violate the maximum length permitted for the LU name. The permissible decimal range of values is 0 through 999, and the permissible hexadecimal range of values is 0 through FFF.

11. In the Number System area, click the desired radio button to specify the numbering system to be used for the extension numbers. The default is Decimal. This selection does not affect LU numbers.

12. The Add Leading Zeros check box is, by default, marked (an X is present) to indicate that the option is active. To turn the option off, simply click the check box containing the X to clear the mark. Leading zeros ensure that LU names appear in the proper sequence.

13. Click OK to clear the Add LU Range dialog box and display the LUA LU Range Properties dialog box shown in figure 23.12.

    Fig. 23.12 - The LUA LU Range Properties dialog box displays the range of LUA LU numbers and names just created.

14. No action is required in the LU Numbers box. It simply displays the range of LU numbers you just created. LU Numbers cannot be modified in this dialog box.

15. No action is required in the LU Names box. It simply displays the range of LU names you just created. LU names cannot be modified in this dialog box.

16. No action is required in the Connection box. It simply displays the connection for the LU range you just created. Connections cannot be modified in this dialog box.

17. The Comment box is optional. If you do decide to enter a comment, you can enter up to 25 characters of free-form text.

18. The LUA High Priority LU check box is, by default, marked (contains an X) to indicate that the LUs in this range have priority over other low-priority LUs. If you want the LUs in this range to have a low priority, unmark the check box (remove the X) by clicking the check box while it contains the X.

19. Click OK to exit the dialog box and accept the settings, or click Cancel to exit the dialog box without accepting the settings. The Servers and Connections window then appears, reflecting the new LUA LU just configured.

Creating and Configuring Downstream LUs

Individual Downstream LUs

The procedure for creating and configuring downstream LUs individually is as follows:

1. In the Servers and Connections window, click any item to make the Servers and Connections window the active window on the SNA Server Admin screen. Then click the connection to which the LU will be assigned.

2. In the SNA Server Admin menu, choose Services, Assign LUs to display the Insert LU dialog box (refer to fig. 23.1).

3. Click Downstream in the New Logical Unit area of the dialog box.

4. Click OK to clear the Insert LU dialog box and display the New Downstream LU Properties dialog box shown in figure 23.13.

   Fig. 23.13 - The New Downstream LU Properties dialog box is used to define the new Downstream LU number and name.

5. In the LU Number box, enter a number for this LU. Although valid numbers range from 1 through 254, SNA conventions dictate that LU numbers always start with 2, not 1. Therefore, the permissible values are really 2 through 254. This number must correspond to the VTAM SysGen parameter, LOCADDR, in the VTAM generator on the host computer. Coordinate with the SNA host administrator for the number to use and enter that number here. If the number you entered has already been assigned to an LU, a message box appears telling you to enter a different number because duplicate LU numbers are not permitted.

   
   The LU number identifies this LU to the IBM host. It does not need to match the Downstream LU number, which identifies the LU to the downstream system.
   

6. The Downstream LU Number box displays the Downstream LU number assigned by the SNA Server when the LU is associated with a downstream connection. Downstream LU numbers cannot be changed in this dialog box, but they can be changed in the Servers and Connections window by performing the following steps:
   1. Reorder the list of LUs in the downstream connection.

   2. Put the undesired numbers in empty LU pools so that the desired numbers are available for other LU pools or LUs.

7. In the LU Name box, enter a unique name for this LU. This name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $). It identifies the LU on the SNA Server only, not on the host or downstream system.

8. No action is required in the Connection box. It simply displays the connection for the LU you are creating and configuring.

9. If this LU has already been assigned to an LU Pool, the name of that pool appears in the Pool box. If it has not yet been assigned to a pool, (None) appears in the Pool box.

10. The Comment box is optional. If you do decide to enter a comment, you can enter up to 25 characters of free-form text.

11. Click OK to exit the dialog box and accept the settings, or click Cancel to exit the dialog box without accepting the settings. The Servers and Connections window appears, reflecting the new Downstream LU just configured.

Range of Downstream LUs

To create and configure a range of consecutively numbered downstream LUs, perform the following steps:

1. In the Servers and Connections window, click the connection to which the LU(s) will be assigned.

2. In the menu bar, choose Services, Assign LUs to display the Insert LU dialog box (refer to fig. 23.1).

3. Click Downstream in the New Logical Unit area of the dialog box.

4. Click Range of LUs (to mark it with an X) to configure several consecutively numbered LUs at one time. (To unmark or clear the X from the Range of LUs check box, click the check box when it is marked.) When you click OK in the Insert LU dialog box with the Range of LUs check box marked, the Add LU Range dialog box appears (refer to fig.23.3).

5. In the Base LU Name box, enter a unique name for the LU range. The LUs in the range will have names composed of this Base LU Name and an extension number, and each name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $). Therefore, the permissible length of the Base LU Name really depends on the number of digits (1, 2, or 3) you will be using for the extension number. For example, if you plan to use two-digit extension numbers (to cover up to 99 individual LUs), the Base LU Name must be limited to six characters. Keep this in mind when entering the Base LU Name.

6. In the First LU Number box, enter a number for the first LU. Although valid numbers range from 1 through 254, SNA conventions dictate that LU numbers always start with 2, not 1. Therefore, the permissible values are really 2 through 254. This number must correspond to the VTAM SysGen parameter, LOCADDR, in the VTAM generator on the host computer. Coordinate with the SNA host administrator for the number to use. If the number you entered has already been assigned to an LU, a message box appears telling you to enter a different number because duplicate LU numbers are not permitted.

7. In the Number of LUs box, enter the number of LUs you want in the range. The SNA Server numbers them sequentially from the first number specified.

   
   Even though the host administrator may instruct you to use LU numbers that are not consecutive, you can still create a range of sequential LU numbers and then modify the individual LU numbers after they have been created.
   

8. No action is required in the Selected LU Range box. It simply displays the range of LU names after you have defined the range. If you do not want to modify the extension number format, go to step 13.

9. Click Options to modify the extension number format. This causes the Add LU Range dialog box to be expanded to include the Extension Numbering Format area (refer to fig. 23.4).

10. The First Extension box displays the default first extension, which is the First LU Number entry in the upper portion of the Add LU Range dialog box. Either accept this default or enter a new first extension number. If the Base LU Name is six characters, the First Extension number cannot be greater than two digits (01-99) so as not to violate the maximum length permitted for the LU name. The permissible decimal range of values is 0 through 999, and the permissible hexadecimal range of values is 0 through FFF.

11. In the Number System area, click the desired radio button to specify the numbering system to be used for the extension numbers. The default is Decimal. This selection does not affect LU numbers.

12. The Add Leading Zeros check box is, by default, marked (an X is present) to indicate the option is active. To turn off the option, simply click the check box containing the X to clear the mark. Leading zeros ensure that LU names display in the proper sequence.

13. Click OK to clear the Add LU Range dialog box and display the Downstream LU Range Properties dialog box shown in figure 23.14.

    Fig. 23.14 - The Downstream LU Range Properties dialog box displays the range of downstream LU numbers and names just created.

14. No action is required in the LU Numbers box. It simply displays the range of LU numbers you just created. LU numbers cannot be modified in this dialog box.

15. No action is required in the LU Names box. It simply displays the range of LU names you just created. LU names cannot be modified in this dialog box.

16. No action is required in the Connection box. It simply displays the connection for the LU range you just created. Connections cannot be modified in this dialog box.

17. The Comment box is optional. If you decide to enter a comment, you can enter up to 25 characters of free-form text.

18. Click OK to exit the dialog box and accept the settings, or click Cancel to exit the dialog box without accepting the settings. The Servers and Connections window appears, reflecting the new Downstream LU just configured.

Grouping the LUs into Pools

• The LUs for the pool have to be configured.

• The pool needs to be created.

• Configured LUs need to be assigned to the pool.

• The pool needs to be assigned to specific users, LUA applications, or downstream systems.

Because earlier sections of this chapter discussed the steps for configuring the various types of LUs, this section explains how to create and configure new 3270, LUA, and Downstream LU pools using the LU Pools window in the SNA Server Admin program.

Because this section focuses on the creation of new LU pools, the New Pool dialog box is used to explain the procedure. You can also access existing LU pools by selecting the specific pool desired for viewing or modification and then choosing Pools, Properties. Instead of the New Pool dialog box appearing, a properties dialog box for the specific LU pool type selected appears. In each case, the information in the selected properties dialog boxes is identical to that displayed in the more generic New Pool dialog box.

3270 LU Pools

1. In the LU Pools window, click any item to make the LU Pools window the active window on the SNA Server Admin screen.

2. In the SNA Server Admin menu bar, Choose Pools, New Pool. The New Pool dialog box appears as displayed in figure 23.15.

   Fig. 23.15 - The New Pool dialog box is used to specify a name for the pool and to select the type of LUs that will be assigned to the pool.

3. In the Pool Name box, enter a name identifying this LU pool. This name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $). This name must be unique from any other LU or pool name, except APPC LU names.

4. In the Comment box, enter any comment up to 25 characters. Entries in this box are optional.

5. In the Pool Type area, select the 3270 type by clicking the 3270 radio button (if the radio button is not already highlighted).

6. In the Display Model area, either accept Model 2 as the default or click the radio button next to the desired display model. The model determines the number of lines and the number of characters per line to be displayed. Some emulators are only capable of emulating certain display models, so you should reference your emulator documentation to determine the display model constraints of your specific emulator.

7. The Model Can Be Overridden check box is, by default, marked (contains an X) to indicate that the display model can be overridden by using the 3270 terminal emulation program. If you do not want to be able to override the display model, unmark the check box (remove the X) by clicking the check box while it contains the X.

   
   A conflict occurs between the Display Model setting for the pool and for an LU in the pool. When this occurs, a message box appears giving you the option of changing the individual LU Display Model setting or excluding the LU from the pool to resolve the conflict.
   

8. Click OK to accept the settings and exit the New LU Pool dialog box, or click Cancel to exit the dialog box without accepting the settings.

LUA LU Pools

1. In the LU Pools window, click any item to make the LU Pools window the active window on the SNA Server Admin screen.

2. In the SNA Server Admin menu bar, choose Pools, New Pool. The New Pool dialog box appears (refer to fig. 23.15).

3. In the Pool Name box, enter a name identifying this LU pool. This name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $). This name must be unique from any other LU or pool name, except APPC LU names.

4. In the Comment box, enter any comment up to 25 characters. Entries in this box are optional.

5. In the Pool Type area, select the LUA type by clicking the LUA radio button (if the radio button is not already highlighted).

6. The LUA High Priority LU Pool check box is, by default, marked (contains an X) to indicate that the LUs in this pool should be given communications preference over LUs in other low-priority pools. If you do not want the LUs in this pool to have priority, unmark the check box (remove the X) by clicking the check box while it contains the X.

   
   A conflict occurs between the priority for the pool and an LU in the pool. When this occurs, a message box appears giving you the option of changing the individual LU priority or excluding the LU from the pool to resolve the conflict.
   

7. Click OK to accept the settings and exit the New LU Pool dialog box, or click Cancel to exit the dialog box without accepting the settings.

Downstream LU Pools

1. In the LU Pools window, click any item to make the LU Pools window the active window on the SNA Server Admin screen.

2. In the SNA Server Admin menu bar, choose Pools, New Pool. The New Pool dialog box appears (refer to fig. 23.15).

3. In the Pool Name box, enter a name identifying this LU pool. The name identifies this pool as being on the SNA Server only, not on a host or downstream system. This name can contain a maximum of eight characters (alphanumeric and the special characters @, #, and $). This name must be unique from any other LU or pool name, except APPC LU names.

4. In the Comment box, enter any comment up to 25 characters. Entries in this box are optional.

5. In the Pool Type area, select the Downstream type by clicking the Downstream radio button (if the radio button is not already highlighted).

6. Click OK to accept the settings and exit the New LU Pool dialog box, or click Cancel to exit the dialog box without accepting the settings.

Assigning LUs to Pools

1. In the LU Pools window, select the pool to which the LU(s) will be assigned. If the pool you want is not in the list, choose View, All LU Pools from the menu and then select the desired pool.

2. Choose Pools, Assign LUs. The Assign Pool LUs dialog box appears as displayed in figure 23.16.

   Fig. 23.16 - The Assign Pool LUs dialog box showing the LUs available for assigning to the pool specified.

3. Select one or more LUs from the list in the Available LUs area.

4. Click OK to place the LU(s) in the selected pool and exit the Assign Pool LUs dialog box, or click Cancel to exit the dialog box without adding the LU(s) to the pool. The LU Pools window once again appears.

The LU Pools window also gives you the capability of deleting LUs from pools and moving LUs between pools. Follow these steps to remove LUs from an LU pool:

1. In the LU Pools window, select the desired pool containing the LUs to be removed. If the pool you desire is not in the list, choose View, All LU Pools and then select the desired pool.

2. The LUs belonging to the pool appear in the LU list on the right side of the LU Pools window. Simply select the LU(s) you want to delete from the pool. The LUs should remain highlighted after selection.

3. In the SNA Server Admin menu bar, choose Edit, Delete.

4. When the confirmation dialog box appears, click Yes to delete the highlighted (selected) LU(s) from the pool, or click Cancel to cancel the delete operation.

Follow these steps to move one or more LUs to a different pool:

1. In the LU Pools window, select the desired pool containing the LUs to be removed. If the pool you desire is not in the list, choose View, All LU Pools and then select the desired pool.

2. The LUs belonging to the pool appear in the LU list on the right side of the LU Pools window. Simply select the LU(s) you want to move. The LUs should remain highlighted after selection.

3. In the SNA Server Admin menu bar, choose Pools, Move, and the Move dialog box appears.

4. In the To LU Pool area select the pool name to which you want to move the previously selected LUs (which should still be highlighted).

5. Click OK to perform the actual move.

This concludes the procedure for grouping the LUs into pools. But you must still accomplish one critical action before the LU pool can be used. That action, discussed in the next section, is assigning the pool to a user or group of users.

Assigning LU Pools to Users and Groups

Adding a Network User or Group

1. In the Users and Groups window, click any item to make the Users and Groups window the active window on the SNA Server Admin screen.

2. In the SNA Server Admin menu bar, choose View, Configured Users.

3. In the menu bar, choose Users, New User. The Add Users and Groups dialog box appears as displayed in figure 23.17.

   Fig. 23.17 - The Add Users and Groups dialog box for a sample domain called INTERNAL.

4. In the List Names From box, click the drop-down list box to display a list of available domains. From this list, either select the name of the local SNA Server or select the domain that contains the users and/or groups to be added.

5. From the list of users and groups displayed in the Names area of the dialog box, select the one to be added.

6. Click Add and then click OK to clear this dialog box and redisplay the Users and Groups window. The title bar of the Users and Groups window now reflects the fact that the window information is out of date and needs to be updated.

7. In the SNA Server Admin menu bar, choose File, Save Configuration. This updates the Users and Groups window to reflect the newly added user(s) and/or group(s).

Configuring User or Group Properties

1. In the Users and Groups window, choose View, Configured Users from the SNA Server Admin menu and select the user or group to be configured.

2. In the Users and Groups window, choose Users, Properties from the menu to display the User Properties (or Group Properties) dialog box, as shown in figure 23.18.

   Fig. 23.18 - The User Properties dialog box is used to select the local and/or remote APPC LUs to serve as the default when the specified user starts APPC programs.

3. In the Comment box, enter any comment up to 25 characters. Entries in this box are optional.

4. In the Local LU Alias box, either accept the default of None, or click the drop-down list box to display a list of local APPC LUs. Select the desired APPC LU to serve as the default to be used when the user starts APPC programs (TPs, 5250 emulators, APPC applications, and so on).

5. In the Remote LU Alias box, either accept the default of None, or click the drop-down list box to display a list of remote APPC LUs. Select the desired remote APPC LU to serve as the default to be used when the user starts APPC programs (TPs, 5250 emulators, APPC applications, and so on).

6. Click OK to accept the settings and exit the User Properties dialog box, or click Cancel to exit the dialog box without accepting the settings. The Users and Groups window once again appears.

Assigning the LUs or LU Pools

1. In the Users and Groups window, choose View, Configured Users from the SNA Server Admin menu.

2. Select the user or group to which the LUs or LU pools are to be assigned. Your selection should remain highlighted.

3. In the Users and Groups window, choose Users, Assign LUs from the menu. The Assign User LU/Pool Sessions dialog box appears, as shown in figure 23.19.

   Fig. 23.19 - The Assign User LU/Pool Sessions dialog box shows the LUs and pools available for assigning to the specified user.

4. In the Available LUs and Pools area of the dialog box, select one or more LUs or LU pools from the list of those available. If a user needs access to more than one LU session at a time, you should assign multiple LUs or LU pools (one for each required LU session) to the same user. You can assign a single LU or LU pool any number of times to the same user.

5. Click OK to clear this dialog box and redisplay the Users and Groups window. The title bar of the Users and Groups window now reflects the fact that the window information is out of date and needs to be updated.

6. In the SNA Server Admin menu bar choose File, Save Configuration. This updates the Users and Groups window to reflect the newly assigned LUs and LU pools.

Configuring Downstream Connections

This section now focuses on the second leg of the connection from the SNA Server to the downstream system. Specifically, it covers the steps for configuring the downstream connection and associating the downstream LUs with that connection.

Configuring a New Downstream Connection

1. In the Servers and Connections window, click any item to make the Servers and Connections window the active window on the SNA Server Admin screen. Then select the server on which the downstream connection will be added.

2. In the SNA Server Admin menu bar, choose Services, New Connection.

3. When the Insert Connection dialog box appears, select one of the available connection types. Note that a downstream connection cannot be the DFT connection type, but it can be of the 802.2, X.25, or SDLC type.

4. Click OK to close the Insert Connection dialog box and display the Connection Properties dialog box for the connection type specified, as shown in figure 23.20.

   Fig. 23.20 - The Connection Properties dialog box is used to specify the connection name and link service type along with a few other parameters.

5. In the Connection Name box, enter a unique name for this connection. The name has a maximum length of eight alphanumeric or special (@, #, and $) characters and cannot be the reserved name SNASERVR.

6. In the Comment box, enter any comment up to 25 characters. Entries in this box are optional.

7. In the Link Service box, click the drop-down list box and select the desired link service from the list. Remember that the link service allows this connection to access your installed communications adapter. If the link service you need is not listed, you must cancel this part of the configuration and go back to install the link service using the SNA Server Setup program.

8. If this downstream connection is of the X.25 type, the Connection Properties dialog box contains a Virtual Circuit Type option. Either accept the default selection (Switched), or override the default by making your own selection. Switched virtual circuits (SVCs) are dynamically called and cleared, and the destination address is supplied when the circuit is called. On the other hand, permanent virtual circuits (PVCs) are constantly active, and the destination address is preset.

9. In the Remote End area of the Connection Properties dialog box, click Downstream.

10. The Activation setting applies only to outgoing calls. Therefore, if the Allowed Directions setting (described in step 11) includes outgoing calls, a default option is highlighted. You can accept the default option or override it by making your own selection. If the connection is configured to accept incoming calls, the connection starts listening for calls whenever the SNA Server is started. The options for the Activation setting are described in the following list:
    • On Server Startup. This is the default option for 802.2 connections. When this option is selected, the connection is started whenever the SNA Server used by this connection is started. This option results in faster access time for the first user who connects after SNA Server startup and is the best choice when communications line charges are fixed regardless of time used rather than assessed for only the time used. Therefore, this option is best for X.25 permanent virtual circuit connections, SDLC leased-line connections, and 802.2 connections.

    • On Demand. This option is not available for downstream connections and will be grayed out.

    • By Administrator. When this option is selected, the administrator must control the connection activation on a case-by-case basis.

11. In the Allowed Directions area of the Connection Properties dialog box, select the appropriate call directions, outgoing, incoming, or both. The default selection is the Outgoing Calls option. For an SDLC type downstream connection, Outgoing Calls must be selected.

12. Click the Setup button to display the appropriate (SDLC, 802.2, or X.25) dialog box.

13. When you are finished setting the parameters in the Setup dialog box for the appropriate connection type, click OK to accept the settings and exit the Setup dialog box.

14. When the Connection Properties dialog box reappears, click OK.

See "Completing Configuration of SDLC Connections," (Ch. 22)

See "Completing Configuration of 802.2 Connections," (Ch. 22)

See "Completing Configuration of X.25 Connections," (Ch. 22)

Associating Downstream LUs with a Downstream Connection

1. Click in the Servers and Connections window to make it the active window. Then select the desired downstream connection with which you want to associate the LUs and LU pools.

2. In the SNA Server Admin menu bar, Choose Services, Assign LUs. The Assign Downstream LU/Pool Sessions dialog box appears as displayed in figure 23.21.

   Fig. 23.21 - The Assign Downstream LU/Pool Sessions dialog box showing the downstream LUs and pools available for assigning to the specified connection.

3. In the Available LUs and Pools area of the dialog box, only available downstream LUs and pools are listed. Select one or more of these LUs or pools to associate with the downstream connection.

4. Click OK to accept the selections and associate them with the downstream connection. The Assign Downstream LU/Pool Session dialog box clears, and the Server and Connections dialog box appears, reflecting the newly associated LUs and LU pools.

From Here...

• To review basic SNA concepts and SNA Server installation procedures, see Chapter 21, "SNA Server Preparation and Installation."

• To review information on building the SNA Server and establishing the connections between the SNA Server and the host mainframe or AS/400 system, see Chapter 22, "Building SNA Server."

• For information on managing the SNA Server on a daily basis as the SNA Server administrator, see Chapter 24, "The Role of the SNA Server Administrator."

• For information on using the Windows NT Server administrative tools as the SNA Server administrator, see Chapter 6, "The Role of the Network Administrator."

Table of Contents

22 - Building SNA Server

24 - The Role of the SNA Server Administrator