Chapter 11: CICS Communications Using Microsoft SNA Server

This chapter is for system administrators responsible for setting up communication links for CICS Option. It tells you how to set up communications for CICS Option, running under Windows NT and using Microsoft SNA Server 3.0 as the communications manager. It provides information about communications between:

• A PC and a mainframe.
• A PC and another PC.

You should be familiar with the concepts and facilities of CICS Option in a single system environment and of CICS intersystem communication. You should also be familiar with the Microsoft SNA Server communications manager.

For information about Mainframe Express and CICS Option, see your User's Guide and your CICS Option Technical Guide.

For information on communication between IBM CICS products, see the IBM publication CICS Family: Interproduct Communication, SC33-0824.

For further information on installing and configuring Microsoft SNA Server, see the Microsoft publications:

• Microsoft SNA Server: Installation Guide
• Microsoft SNA Server: Administration Guide
• Microsoft SNA Server: Reference
• Microsoft SNA Server: APPC Programmer's Guide

11.1 SNA Server Hardware and Software Requirements

For details of the hardware and software requirements to run Microsoft SNA Server, please see the Microsoft manual Microsoft SNA Server: Installation Guide supplied with the SNA server product.

11.2 PC Configuration Definitions

11.2.1 Terminology

The terminology used for configuration items often differs according to the communications service manager being used. The following table contains a generic terminology that is used in this chapter. The mapping from this generic terminology to each of the supported communications services manager's terminology is also shown. The names in parentheses indicate other names or abbreviations for the given term.

11.3 PC to Mainframe Communication

To allow the Mainframe Express CICS Option to communicate with a mainframe application, an LU 6.2 link is required from the PC to the mainframe. The LU 6.2 link is separated into PC and mainframe components.

All the definitions that you require to configure the Microsoft SNA Server should be provided to you by your VTAM host system administrator. In the example described later, we are going to configure an 802.2 DLC connection, as this is the most commonly used. For other types of links, please refer to the Microsoft SNA Server documentation. Though there are many similarities between the different links, you need to consult with your network system administrator or VTAM system administrator to get the required information.

11.3.1 Definitions Used in the Examples

The following table contains a list of definitions that you require to configure an 802.2 DLC connection, along with the settings that we are going to use in this example. One of the most common causes for confusion when configuring SNA is that different SNA servers and environments use different terms to define the same thing. Also there can be additional confusion since a value on one side of a connection has a different perspective, hence name, on the other side of the connection.

From your VTAM system administrator you require the following information.

11.3.2 Configuring SNA Server

This section describes how to configure an 802.2 DLC connection. It assumes that you have installed a 32-bit DLC driver to provide support over an 802.2 DLC connection and that you have installed the Microsoft SNA Server 3.0 product.

First, start the SNA Server Manager. All the following steps to define the configuration are done through that application.

11.3.2.1 Configuring the Local Server

During the SNA Server installation (assuming that you are performing a new installation and not an upgrade) you are prompted for information about the Local Server. In this example, we are going to configure an SNA Server called 'SNASRVR'.

1. Enter the Network Name for this SNA Server. In this example it is 'HSTNET1'.

2. Enter the Control Point Name assigned to this machine. The CP name should match the physical unit (PU) name assigned to this machine in the VTAM PU definition. In this example it is 'MCOPU020'.

Note: These parameters are used as defaults. If you are going to connect to more than one remote system then they can be overridden in the connection definition - see the section Configuring the System Identification.

11.3.2.2 Configuring the Link Service

Now configure the Link Service by clicking Link Service on the Insert menu . This displays the Insert Link Service dialog box. We are going to configure 'SNADLC1'

1. Highlight the item 'DLC 802.2 Link Service' and click Add.... This displays the DLC 802.2 Link Services Properties dialog box.

2. In the Adapter field, select the correct LAN adapter over which the link service will be used.

3. If you want this machine to have more than one PU to the same host, you need more than one link service, because each PU to the same host requires a unique Local Service Access Point (SAP) address. If you are defining your first link service, the default of 4 is fine. If you are going to have multiple PUs to the same host, this number needs to be a multiple of 4 and in the range 04 through EC.

4. Click OK to complete the configuration of the Link Service.

11.3.2.3 Configuring the Connection

1. In the SNA Servers folder, select the Local Server that you configured previously.

2. On the Insert menu, click Connection and then the connection type 802.2. The Connection Properties dialog box appears.

3. If the General page is not already displayed, click the General tab.

4. In the Name field, enter a name, up to 8 characters long, to identify the connection. In this example it is 'MVSHOST1'.

5. Select the Link Service you intend to use for this connection. In this example it is 'SNADLC1'.

6. For Remote End, select 'Host System'.

7. For Allowed Directions, select 'Both Directions'.

8. For Activation, select 'By Administrator' initially. You can change this to 'On Demand' or 'At Server Startup' later when you have verified that the connection is configured correctly.

11.3.2.4 Configuring the Connection Address

Click the Address tab to display the Address page.

1. Enter the 12-digit hexadecimal Remote Network Address of the network controller attached to the remote host system. In this example it is '400000004044'.

11.3.2.5 Configuring the System Identification

Click the System Identification tab to display the System Identification page.

1. If you are configuring more than one PU to the same or different host on this SNA Server, you can override the default values of Network Name and Control Point Name. In this example we use the values of 'HSTNET1' and 'MCOPU020'.

2. Enter the 8-digit hexadecimal Local Node ID. In this example it is 05D,22222.

3. Select the XID Type that you are going to use. In this example it is 'Format 3', the default.

4. If you are using XID Format 3, enter the remote Network Name and Control Point Name. In this example they are 'HSTNET1' and 'HSTMVS'.

5. If required, enter the Remote Node ID. In this example it can be left blank.

11.3.2.6 Configuring 802.2 DLC Properties

Click the 802.2 DLC tab to display the 802.2 DLC page.

1. Enter the Max BTU Length. In this example it is '1493'.

2. Click OK to complete the configuration of the connection.

Before attempting to communicate to the host you must define the local and remote LUs which will be used to communicate over the SNA connection you have configured. The next sections describe the configuration of Independent LUs to be used to communicate over the host connection. When communicating with host systems running VTAM (or NCP) the Remote LU is known as the APPLID (pronounced 'apple-eye-dee').

11.3.2.7 Configuring Local APPC LUs

If you are using multiple APPC LUs, you can configure each of them as follows:

1. In the SNA Servers folder, select the Local Server that you configured previously.

2. On the Insert menu, click APPC and then Local LU. The Local APPC LU Properties dialog box will appear.

3. If the General page is not already displayed, click the General tab.

4. For LU Alias, specify the LU name from the list of LUs defined for this PU in VTAM on the host system. This name is automatically duplicated for the LU name. In this example it is 'MCOLU021'.

5. The Network Name field automatically defaults to the value specified in Configuring the Local Server. If you are configuring a connection to a host that is not the one specified as default, use the value specified in Configuring the System Identification. In this example we use the default of 'HSTNET1'.

6. Select the Advanced tab in the Local APPC LU Properties dialog box.

7. For LU 6.2 type, select 'Independent'.

8. Click OK to complete the configuration of the Local LU.

11.3.2.8 Configuring Remote LUs

A remote LU is assigned to a connection that is used to communicate with the LU.

1. In the SNA Servers folder, select the Local Server that you configured previously.

2. On the Insert menu, click APPC and then Remote LU. The Remote APPC LU Properties dialog box will appear.

3. If the General page is not already displayed, click the General tab.

4. In the Connection field, select the connection over which this Remote LU will be used. This is the connection configured in Configuring the Connection. In this example it is 'MVSHOST1'.

5. Enter the LU Alias. This name is automatically duplicated for the LU Name and the Uninterpreted Name. In this example it is 'HSTCICS1'.

6. The Network Name defaults to the value specified for the connection. In this example it is 'HSTNET1'.

7. Select the Options tab in the Remote APPC LU Properties dialog box.

8. Ensure that Supports Parallel Sessions is selected.

9. Select an Implicit Incoming Mode from the available list. If you are not using a standard mode, you need to define the one you are going to use before you can complete configuring the Remote APPC LU. In this example we use '#INTER'.

10. Click OK to complete the configuration of the Remote LU.

Notes:

1. On Local LU and Remote LU Mode characteristics, when a connection is established between a Local LU and a Remote LU, the Mode characteristics are negotiated. This means that it is possible that the partner system (for example, the mainframe) will reduce the session limits to values which it can support. This may mean that fewer client sessions than expected will be supported. Hence it is important that the Mode characteristics as defined for both the Local and Remote LUs are compatible.

2. If you have more sessions defined in the Session Maximum parameter in your Mainframe Express CICS system for the given connection than has been negotiated, then not all of these sessions will become available. This will lead to ISC sessions seemingly hanging or timing out until others have been released.

11.3.2.9 Adding a User

In order to use a connection you need to be defined to SNA server as a user. You can do this as follows:

1. On the Insert menu, click User. The Add User and Groups dialog box will appear.

2. Select the domain from which to add the user or groups, or select the local server name.

3. Select the user or group from the list in the Names list box (click the Members… button to list the users in a group) and then click Add. More than one user can be added at a time by multiple selections and Add operations. In this example we assume we have added a local user called 'MCOU'.

4. Click OK to complete the adding of a user.

11.3.2.10 Configuring a 3270 LU for the 3270 Applet

In order to use the SNA Server 3270 Applet for 3270 terminal access to the host system, a 3270 LU must be configured for use by each terminal session.

1. In the Connections folder, select the connection over which the 3270 session will be used.

2. On the Insert menu, click 3270 and then Display LU. The 3270 LU Properties dialog box will appear.

3. If the General page is not already displayed, click the General tab.

4. Set the LU number for this dependent LU. In this example it is '2'.

5. Set the LU Name for this dependent LU. In this example it is 'MCOTRM22'.

6. Select the Display Model tab in the 3270 LU Properties dialog box.

7. Set the Display Model Attributes. These can usually be left to default to '2 (25x80)' and 'Model can be overridden'.

8. Click OK to complete the configuration of the 3270 LU.

9. This operation can be repeated for other 3270 dependent LUs for your PU. In this example, we would repeat it for LU MCOTRM23 with an LU number of 3 and MCOTRM24 with an LU number of 4.

11.3.2.11 Associating a 3270 LU with a User

When a user runs the SNA Server 3270 Applet, a 3270 LU is required in order to establish a 3270 session with the host system. This LU may come from a pool of 3270 LUs or may be associated with the user. In this example, we define a pool and associate a user to this pool.

1. On the Insert menu, click Pool and then 3270 Display LU Pool. The Pool Properties dialog box appears.

2. If the General page is not already displayed, click the General tab.

3. In the Pool field, enter an 8-character name to identify your pool. It is best to give it a meaningful name if you are going to have multiple pools. In this example it is 'HSTPOOL'.

4. Select the Display Model tab in the Pool Properties dialog box.

5. Set the Display Model Attributes. These can be set to '2 (25x80)' and 'Model can be overridden'.

6. Click OK to complete the creation of the pool.

7. Select the Pools folder and then select the pool you have defined - 'HSTPOOL' in this example.

8. Right-click on your pool to bring up the popup menu. Click Assign To User and then click the user name that you wish to assign to this pool. In this example it is 'MCOU'.

11.3.2.12 Saving the Configuration

When you want to save the configuration, click Save on the File menu.

11.3.2.13 Activating the Configuration

To activate the configuration, you must stop and restart the SNA Server service, as follows:

1. In the SNA Servers folder, select the server and then, on the Service menu, click Stop. In this example the server is 'SNASRVR'.

2. When the server status has gone to 'Inactive', click Start on the Services menu. The server should then go to 'Active' status.

When the server is active, the underlying connections activate if the 'Activation Type' was defined as 'On Server Startup' or 'On Demand', as described in the section Configuring the Connection.

Connections configured for Incoming and Outgoing calls go to 'On Demand/Incoming' status when successfully activated. The connection goes to the 'Active' status when the first session is established or if activated manually by the administrator.

11.3.2.14 Client Installation of SNA Server

If you are using a client installation of SNA Server you still need to complete the SNA Server configuration as described above. Also, when you install the SNA client software, you need to set it to point to the defined server. When the client is correctly installed, the operation and configuration of CICS Option is the same on the client machine as on the server.

11.3.3 Connecting CICS Option to a Host CICS Region

You need to configure CICS Option to communicate with the host CICS region. If you have the SNA Server to host connection working, as described in the previous section, then the configuration of CICS Option and the host CICS region should be simple.

The parameters that you require for configuring CICS Option to the host are:

11.3.3.1 Defining a CICS Option Connection to a Host CICS System

To define a CICS Option connection to the host you need to follow the steps below:

1. Start Mainframe Express.

2. Load or define the project for the region that you want to communicate with the host.

3. On the Tools menu, click CICS and then Resource Definition.

4. Press F7 =group resources.

5. Add or select a group to add your connection definition to. In this example it is 'HSTGROUP'.

6. When the group has been selected, press F9 =terminal/connection. Then press F3 =connection.

7. Enter the Connect id. by which the host will be known to your local system That is, the SYSID of the host as used in SYSID() entry of the EXEC CICS statements or the 'System ID' as used in the resource definition. In this example it is 'HST1'.

8. Press F3 =add.

9. Tab to the Description field and optionally enter a description.

10. Tab to the Connection type field and enter LU6.2

11. Tab to the LU alias field and enter the independent LU name for your PU as defined on VTAM. In this example it is 'MCOLU021'.

12. Tab to the Partner alias field and enter the APPLID of the remote CICS system. In this example it is 'HSTCICS1'.

13. Tab to the Alias applid field and enter the APPLID of the local system as defined to the host. In this example it is 'MCOLU021'.

14. Tab to the Mode table field and enter the mode table that SNA Server and the host are going to use. In this example it is '#INTER'.

15. Tab to the Session maximum field and enter the maximum number of sessions between LU-LU pairs that CICS Option will allow. Please note that the maximum supported number allowed by CICS Option is 5. In this example we use 005.

16. Tab to the Net name field and enter the network name of this CICS system. In this example it is 'MCOPU021'.

17. Press F10 =save to save the record.

The definition is shown in Figure 11-1:

Figure 11-1: Definition of Host Connection

11.3.3.2 Including the Resource Group in the Startup List

Now you need to ensure that the resource group with the host CICS system's definitions is included in the startup list, as follows:

1. Click the CICS tab on the Project View.

2. Right-click on CICS System to display the associated context menu.

3. Click Startup List to display the Startup List Configuration dialog box.

4. Check whether the group containing the host CICS system's definitions is in the left-hand list of Groups in Startup List. If not:
   1. Select the group from the right-hand list.

   2. Click << Add to move it to the left-hand list.

   3. Click OK to confirm the move.

11.3.4 Defining a Host CICS Connection to the Local CICS Option System

In order for the host CICS region to recognise the local CICS Option, you need to define a connection definition and an associated session. On most host systems, CICS region changes are usually applied by system administrators, so you will probably need to liaise with them.

You need to have a resource group for the connection and session definitions. In this example we use group 'HSTTOSNA'. The connection name is 'LU21' and the session name is 'LU21SESS'. You can use an SNA Server 3270 applet to configure the host CICS system by entering the VTAM ID of your host CICS region when the terminal has a connection to the host VTAM system.

To configure the host CICS regions we are going to use the IBM-supplied transaction CEDA. For more information on the CEDA transaction, see the IBM publication CICS/ESA 3.3 Resource Definition.

In the following examples of using CEDA, you can accept the default values for the fields that are not mentioned. When you have defined your connection and sessions, and have tested them, you will probably want to have them installed automatically on the host CICS region startup. You can do this by adding the group to your CICS startup list.

1. In CICS, on the host system, enter the transaction 'CEDA DEFINE GROUP(group_name) CONNECTION(connection_name)', where group_name is the name of the group containing the connection connection_name. In this example we would enter 'CEDA DEFINE GROUP(HSTTOSNA) CONNECTION(LU21)'

2. In the Netname field, under Connection Identifiers, type the netname of you local CICS Option system and press Enter. In this example the netname is 'MCOLU021'. You should receive the message 'Define Successful' near the bottom of the screen.

3. Press PF3 to end CEDA, followed by Clear.

4. Enter the transaction 'CEDA DEFINE GROUP(group_name) SESSION(session_name)', where group_name is the name of the group containing the session session_name. In this example it is 'CEDA DEFINE GROUP(HSTTOSNA) SESSION(LU21SESS)'

5. In the Connection field, under Session Identifiers, type the name of the connection you have defined. In this example it is 'LU21'.

6. In the MOdename field, under Session Identifiers, type the name of the mode table that you are using. In this example it is '#INTER'.

7. In Session Properties you need to enter the maximum number of sessions in the group and the maximum number of contention winners. We will use 8 and 4 respectively.

8. You may also need to change send size and receive size, depending on your mode table. We will keep the defaults.

9. Press Enter and you should receive the message 'Define Successful' near the bottom of the screen.

10. Press PF3 to end CEDA, followed by Clear.

11.3.4.1 Defining a Terminal for Transaction Routing

On some versions of VTAM you might need to define a terminal so that you can perform transaction routing to the host CICS region from the local CICS Option. This is indicated by the error message 'TXCS1012E Comms error x'0006' during route of TRAN to system HST1' when you enter the first transaction ID to be run on the host CICS region.

If you do need to define a terminal, you also need to change the default terminal configuration as described in the section Configuring a Default Terminal. In this example we are going to configure a terminal called 'L21A'.

1. Enter the transaction 'CEDA DEFINE GROUP(group_name) TERMINAL(terminal_id)', where group_name is the name of the group containing the terminal_id terminal definition. In this example we would enter 'CEDA DEFINE GROUP(HSTTOSNA) TERMINAL(L21A)'

2. Enter the following details under Terminal Identifiers: ' Typeterm = DFHLU2', 'Netname=L21A', 'REMOTESYSTem = LU21', and 'REMOTEName = L21A'.

3. Press Enter and you should receive the message 'Define Successful' near the bottom of the screen.

4. Press PF3 to end CEDA, followed by Clear.

11.3.4.2 Installing the Definitions

After you have defined the connection, the session, and, if required, the terminal, you need to install these definitions. As a connection and session are paired you need to install the group that they are contained in rather than the individual entries.

• On your host CICS region, enter 'CEDA INSTALL GROUP(HSTTOSNA)'.
• Your should get the message 'Install Successful'.

11.3.4.3 Configuring a Default Terminal

You only need to do this if you are getting the message 'TXCS1012E Comms error x'0006' during route of TRAN to system HST1' when you enter the first transaction ID to be run on the host CICS region. See the section Defining a Terminal for Transaction Routing for more information.

1. On the Mainframe Express Tools menu, click CICS, then Region Management, and then Configure Default Terminal. This displays the Configure Default 3270 Terminal dialog box.

2. Under Terminal definition, set Based on to 'Netname' and Name to 'XXXXaaaa', where 'aaaa' is the name of the terminal defined on the host CICS region. In this example it is 'XXXXL21A'. The last four characters of the netname are used as the terminal identifier. See the section Terminal Installation Parameters in the chapter Configuring CICS Terminals and Printers for more information on the setting of netname.

11.3.5 Testing the Connection to the Host CICS System

To test your connection to the host CICS system you need to ensure that:

1. The Microsoft SNA server has an active link to the host.

2. The host CICS region is running. In most installations this is the case, but sometimes you may need to ask your host system administrator to start the host CICS region that you are going to connect with. It can usually be tested by using an SNA Server 3270 applet and entering the VTAM ID of your host CICS region when the terminal has a connection to the host VTAM.

11.3.6 Starting the Local CICS Option

1. On the Mainframe Express Tools menu, click CICS and then Start Region. In the console window, wait until both initialization phases have been run.

2. Click CICS and then Start 3270 terminal. This starts the 3270 terminal emulator for CICS Option, not the SNA server.

3. Complete any sign-on procedure required by your system.

4. Enter the transaction CRTE SYSID=HST1, replacing HST1 by your connection definition name. You should now get the following message 'DFH4409 The routing session to system HST1 has been started'. This initiates transaction routing for this terminal without acquiring any resources, so the connection has not been tested yet.

5. Enter a transaction that you know exists on the host CICS system. A good one to try would be 'CEMT INQUIRE CONNECTION' which should return the following information:

   IN CONN
   STATUS:  RESULTS - OVERTYPE TO MODIFY 
   Con(COA1) Net(COA1REMT)  Ins Rel  Vta Appc
   Con(LU21) Net(MCOLU021)  Ins Acq  Vta Appc

   In the list of connections, you should see the connection that you have defined and the netname associated with it. It should also have the acquired status (Acq).

11.3.7 System Requirements for Inbound Communications

11.3.7.1 Defining Transaction Programs

If you have reached this point successfully, you should now have SNA Server configured and connected to the VTAM host system. CICS Option should be able to use transaction routing, function shipping, and distributed program linking (DPL) to the host system.

At this stage, you are not able to use transaction routing, function shipping, or DPL from the host CICS region. Also, distributed transaction processing (DTP) does not work because the host CICS region is currently unable to initiate tasks on the local CICS Option.

So, the next step is to define transaction programs (TPs) to the local SNA Server (or client connected to an SNA Server) so that it knows how to invoke CICS Option.

For inbound communications, SNA Server requires registry entries to be created for each transaction used on the SNA server or client that is going to be running CICS Option. These entries are used by the Microsoft SNA Server to start the CICS Option program dfhgatch.exe which routes the request to the correct CICS Option region and transaction.

As all of the Mainframe Express environment settings are contained in the registry, there is no need to set any Mainframe Express environment variables as in previous releases of the Micro Focus CICS Option. The registry entries for the transaction programs can be found in the following location:

Windows NT:

/HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/SnaBase/Parameters/TP's/tpname/Parameters

Windows 95:

/HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/SnaBase/Parameters/TPs/tpname/Parameters

You can use the supplied program mftpset.exe to add inbound transaction program information to the registry:

1. Start a Mainframe Express command prompt.

2. Run mftpset.exe. This displays a dialog box which enables you to add or overwrite the registry entry for the inbound transaction program.

3. Specify the TP Name. This is used to identify the transaction program to the SNA and should correspond to the transaction the host system is trying to run on the local CICS Option (for example, CRTE).

4. Specify the Command line that starts the transaction on the local CICS Option.

5. Specify the name of the Local LU Alias as defined to SNA server for the inbound request. This is the independent LU that you are going to use for your PU as defined to VTAM (for example, MCOLU021).

6. Click OK.

For more information on adding and editing transaction programs, see the Microsoft SNA Server: APPC Programmer's Guide.

On Windows NT the program, tpstart.exe, supplied with SNA Server, must be started. To ensure that it is always running, you should add the program to your startup list.

An important point about tpstart.exe is that it only reads the registry when it is started. So, if you have updated the registry by adding or changing a TP, you need to stop and restart tpstart.exe to pick up any updates.

The following TPs must be defined for inbound function shipping, transaction routing, and distributed program linking:

For inbound function shipping, transaction routing, or distributed program linking, you must add the resource group DFHISC to the startup list in the SIT that contains the PCT definitions for the above transactions.

11.3.7.2 Testing Inbound Transaction Routing from the Host

When you have added the required TP definitions to the registry you are able to perform inbound transaction routing from the host. This tests the last part of the configuration.

To test your connection to the host you need to ensure that the:

1. Microsoft SNA server has an active link to the host.

2. The host CICS region is running. In most installations this is normally the case, but sometimes you may need to ask your host system administrator to start the host CICS region that you are going to connect with. It can usually be tested by using an SNA Server 3270 applet and entering the VTAM ID of your host CICS region when the terminal has a connection to the host VTAM.

3. For Windows NT, you have the supplied program tpstart.exe running on the local machine, and it was started after the CRTR TP was added.

4. You have restarted the region as described in the section Starting the Local CICS Option.

When the previous steps have been done:

1. Start a Microsoft SNA Server 3270 applet to the host VTAM, as described earlier, and connect to the host CICS region.

2. When you have a session on the host CICS region, run the supplied transaction 'CRTE SYSID=local', where local is the name of the connection that you defined earlier. In this example it is 'CRTE SYSID=LU21'.

3. You should now be able to use the SNA Server 3270 applet as if it were a terminal on your local CICS system. To prove the connection, run the transaction CENV supplied with CICS Option. This should give you information about your local CICS system. When you have completed transaction routing enter the 'CANCEL' command.

Note: When transaction routing is active in one direction, you cannot then route back on yourself because the original terminal-id is passed back and this is not unique. All terminal-ids must be unique within a CICS region, both on the host and the local CICS Option.

11.4 PC to PC Communication

Mainframe Express CICS Option can communicate, over a Microsoft SNA Server network, with another PC running CICS Option or another transaction processing system. This section describes how to configure the SNA Server to communicate with another PC running a communications services manager. It describes the configuration of SNA Server 3.0. You should refer to the appropriate communications document for the definitions required for another communication services manager.

There are two methods for achieving PC to PC communication using Microsoft SNA Server.

1. Using a single copy of Microsoft SNA Server. This can be done only in a local network environment in much the same as the Micro Focus CCI support.

2. Using two communication servers. For example, two Microsoft SNA Servers or one Microsoft SNA Server and another communication services manager. This method allows communications between two separate networks via any supported protocols, such as SDLC.

Both methods are described below.

11.4.1 Configuring Microsoft SNA Server in a Local Peer Environment

The configuration of peer to peer communication using a local Microsoft SNA Server is very simple and requires a minimum number of settings. These need to be unique to your SNA server and the two CICS Option regions that are going to be connected. You may need to check with your system administrator that the values you are going to use are unique.

We are going to configure two peer to peer CICS Option regions called REGION1 and REGION2. They require two local LUs. One is called MACHINE2 and goes from REGION1 to REGION2. The other is called MACHINE1 and goes from REGION2 to REGION1. The APPC Mode we are going to use is #INTER.

11.4.1.1 Configuring the Local APPC LUs

On the SNA Server machine, start the SNA Server Manager.

1. In the SNA Servers folder, select the server for which you are going to configure the local LUs.

2. On the Insert menu, click APPC and then Local LU. The Local APPC LU Properties dialog box will appear.

3. For LU Alias, specify the name of the first LU that you are going to define - in this case MACHINE1. The LU name should be automatically duplicated in the LU Name field.

4. Click OK to complete the configuration of the Local LU.

5. Add a second local LU in the same way, with an LU Alias of MACHINE2.

11.4.1.2 Configuring the Local CICS Regions

You now need to configure the two regions that you want to run the transactions on. For this you should define a connection for each region. Here we are going to add a connection on the local region REGION1 to the remote region REGION2, calling the connection REG2.

1. In Mainframe Express, open or create a project that you wish to contain your region.

2. On the Tools menu, click CICS and then Resource Definition. The Resource Definition Facility screen will appear.

3. Press F7 =group resources.

4. Add or select a group for your connection definition.

5. Press F9 =terminal/connection. Then press F3 =connection.

6. Enter the Connect. id. of REG2.

7. Press F3 =add.

8. Tab to the Connection type field and enter LU6.2.

9. Tab to the LU Alias field and enter the APPC Local LU name for the LU that is going to be used to talk to the second region. In this example it is MACHINE2.

10. Tab to the Partner alias field and again enter the APPC Local LU name for the LU that is going to be used to talk to the second region. In this example it is MACHINE2.

11. Tab to the Alias applid field. This is the field by which the Local LU for this region is known to the network. It is normally the same as LU Alias, which in this example is MACHINE2.

12. Tab to the Mode table field and enter the APPC mode that you are going to use. In this example it is #INTER.

13. Tab to the Session maximum field and enter the number of session that you require. The maximum supported by CICS Option is 5. In this example, enter 5.

14. Tab to the Net Name field and enter the network name by which the remote region will be known. In this example it is REGION2.

Repeat the previous steps for the connection on the remote region REGION2 to the local region REGION1, calling the connection REG1.

You can have both connections defined to both regions, in which case you will notice that when the regions are started they will take on the connection ID for their local SYSID. Thus, in this example, the local SYSID of REGION1 is REG1.

11.4.1.3 Configuring the Transaction Program Definitions

As with PC to Mainframe Communication described earlier in this chapter, you will need to add registry entries for each region for inbound requests. Follow the steps described in the section Defining Transaction Programs, replacing the region name MCOTOHST with REGION1 and REGION2.

Note: It is difficult to set up two regions on the same machine for anything but transaction routing of a PCT entry, because you cannot have two TPs defined in the registry with the same transaction name.

11.4.1.4 Configuring Terminals

As a CICS system cannot have duplicate terminals IDs attached at one time, you need each region to have a unique terminal ID. Otherwise you can have situations where you get the following message TXCS1012E Comms error x'0006' during route of TRAN to system REG2. This would be caused by the fact that both regions have terminals connected that share the same terminal ID. To avoid this you could configure default terminals for both regions, as described in the section Configuring a Default Terminal, such that both regions have a different terminal ID - for example, 1111 for REGION1 and 2222 for REGION2. Or you could use an autoinstall program as discussed in the chapter CICS Installation Verification for Communications.

11.4.1.5 Testing the Connections

To test the connection you need to ensure:

1. The Microsoft SNA server has been started.

2. If you are running your region on Windows NT you have the Microsoft supplied program tpstart.exe running.

3. You have started the regions as described in the section Starting the Local CICS Option.

You can now test the connection on either region. For example, for REGION1:

1. Click CICS and then Start 3270 terminal. This starts the 3270 terminal emulator for CICS Option.

2. Complete any sign-on procedure required by your system.

3. Enter the transaction CRTE SYSID=REG2, replacing REG2 with the connection ID that you are going to use. You should get the following message DFH4409 The routing session to REG2 has started. This initiates transaction routing for this terminal without acquiring any resources.

4. Enter the transaction CENV. This displays the settings for the remote region. In this case you should see 'TXREGN=REGION2'.

5. To end transaction routing, enter CANCEL.

6. You can repeat this test from the other region, REGION2.

11.4.2 Configuring Microsoft SNA Server for Two Separate Networks

All the definitions that you require to configure the Microsoft SNA Server should be provided to you by your remote peer-system administrator. In the example described later, we are going to configure an 802.2 DLC connection, as this is the most commonly used. For other types of links, please refer to the Microsoft SNA Server documentation. Though there are many similarities between the different links you need to consult with your network system administrator or remote peer-system administrator to get the required information.

11.4.2.1 Definitions Used in the Examples

In the example, we are going to configure an SNA Server to talk to a peer communications manager. This could be another CICS Option on another SNA Server. We are going to assume that the Local SNA Server is going to be the server for a region called REGION1, which is running under a PU called SNASYS1 with an LU also called SNASYS1. This is talking to a region called REGION2 running under a PU called SNASYS2 with an LU also called SNASYS2.

The following table contains a list of definitions that you require to configure an 802.2 DLC connection, along with the settings that we are going to use in the example. One of the most common causes for confusion when configuring SNA is that different SNA servers and environments use different terms to define the same thing. Also there can be additional confusion since a value on one side of a connection will have a different perspective, hence name, on the other side of the connection.

From your remote peer-system administrator you will require the following information.

11.4.2.2 Configuring SNA Server

This section describes how to configure an 802.2 DLC connection. It assumes that you have installed a 32-bit DLC driver to provide support over an 802.2 DLC connection and that you have installed the Microsoft SNA Server 3.0 product.

First, start the SNA Server Manager. The following steps to define the configuration are done through that application.

11.4.2.3 Configuring the Local Server

During the SNA Server installation (assuming that you are performing a new installation and not an upgrade) you will be prompted for information about the Local Server. In this example, we are going to configure an SNA Server called 'SNASRVR'.

1. Enter the Network Name for this SNA network. In this example it is 'SNANET1'.

2. Enter the Control Point Name assigned to this machine. In this example it is 'SNASYS1'.

Note: These parameters are used as defaults. If you are going to connect to more than one remote system then they can be overridden in the connection definition - see the section Configuring the System Identification.

11.4.2.4 Configuring the Link Service

Now configure the Link Service by clicking Link Service on the Insert menu . This displays the Insert Link Service dialog box. We are going to configure 'SNADLC1'

1. Highlight the item 'DLC 802.2 Link Service' and click Add.... This displays the DLC 802.2 Link Services Properties dialog box.

2. In the Adapter field, select the correct LAN adapter over which the link service will be used.

3. If you want this machine to have more than one PU to the same remote system, you need more than one link service, because each PU to the same remote system requires a unique Local Service Access Point (SAP) address. If you are defining your first link service, the default of 4 is fine. If you are going to have multiple PUs to the same remote system, this number needs to be a multiple of 4 and in the range 04 through EC.

4. Click OK to complete the configuration of the Link Service.

11.4.2.5 Configuring the Connection

1. In the SNA Servers folder, select the Local Server that you configured previously.

2. On the Insert menu, click Connection and then the connection type 802.2. The Connection Properties dialog box will appear.

3. If the General page is not already displayed, click the General tab.

4. In the Name field, enter a name, up to 8 characters long, to identify the connection. If you are defining multiple connections, a meaningful name is recommended. In this example it is 'SNASYS2'.

5. Select the Link Service you intend to use for this connection. In this example it is 'SNADLC1'.

6. For Remote End, select 'Peer System'.

7. For Allowed Directions, select 'Both Directions'.

8. For Activation, select 'By Administrator' initially. You can change this to 'On Demand' or 'At Server Startup' later when you have verified that the connection is configured correctly.

11.4.2.6 Configuring the Connection Address

Click the Address tab to display the Address page.

1. Enter the 12-digit hexadecimal Remote Network Address or MAC address of the network controller/card attached to the remote PC. In this example it is '0123456789AB'.

11.4.2.7 Configuring the System Identification

Click the System Identification tab to display the System Identification page.

1. If you are configuring more than one PU to the same or different remote system on this SNA Server, you can override the default values of Network Name and Control Point Name. In this example we use the defaults of 'SNANET1' and 'SNASYS1'.

2. Enter the 8-digit hexadecimal Local Node ID. In this example it is 05D,12345.

3. Select the XID Type that you are going to use. In this example it is 'Format 3', the default.

4. Enter the remote Network Name and Control Point Name. In this example they are 'SNANET1' and 'SNASYS2'.

5. Enter the Remote Node ID. In this example it is 05D,54321.

6. Click OK to complete the configuration of the connection.

Before attempting to communicate with the remote system you must define the local and remote LUs which will be used to communicate over the SNA connection you have configured. The next sections describe the configuration of independent LUs to be used to communicate over the remote system connection.

11.4.2.8 Configuring Local APPC LUs

If you are using multiple APPC LUs, you can configure each of them as follows:

1. In the SNA Servers folder, select the Local Server that you configured previously.

2. On the Insert menu, click APPC and then Local LU. The Local APPC LU Properties dialog box will appear.

3. If the General page is not already displayed, click the General tab.

4. For LU Alias, specify the LU name for this connection. This name is automatically duplicated for the LU name. In this example it is 'SNASYS1'.

5. The Network Name field automatically defaults to the value that you specified in the section Configuring the Local Server. If you are configuring a connection to a remote system that is not the one specified as default, use the value specified in the section Configuring the System Identification. In this example it is 'SNANET1'.

6. Select the Advanced tab in the Local APPC LU Properties dialog box.

7. For LU 6.2 type, select 'Independent'.

8. Click OK to complete the configuration of the Local LU.

11.4.2.9 Configuring Remote LUs

A remote LU is assigned to a connection that will be used to communicate with the LU.

1. In the SNA Servers folder, select the Local Server that you configured previously.

2. On the Insert menu, click APPC and then Remote LU. The Remote APPC LU Properties dialog box will appear.

3. If the General page is not already displayed, click the General tab.

4. In the Connection field, select the connection over which this Remote LU will be used. This is the connection configured in the section Configuring the Connection. In this example it is 'SNASYS2'.

5. Enter the LU Alias. This name is automatically duplicated for the LU Name and the Uninterpreted Name. In this example it is 'SNASYS2'.

6. The Network Name defaults to the value specified for the connection. In this example it is 'SNANET1'.

7. Select the Options tab in the Remote APPC LU Properties dialog box.

8. Ensure that Supports Parallel Sessions is selected.

9. Select an Implicit Incoming Mode from the available list. If you are not using a standard mode, you need to define the one you are going to use before you can complete configuring the Remote APPC LU. In this example we use '#INTER'.

10. Click OK to complete the configuration of the Remote LU.

Notes:

1. On Local LU and Remote LU Mode characteristics, when a connection is established between a Local LU and a Remote LU, the Mode characteristics are negotiated. This means that it is possible that the partner system will reduce the session limits to values which it can support. This may mean that fewer client sessions than expected will be supported. Hence it is important that the Mode characteristics, as defined for both the Local and Remote LUs, are compatible.

2. If you have more sessions defined in the Session Maximum parameter in your CICS system for the given connection than has been negotiated, then not all of these sessions will become available. This will lead to ISC sessions seemingly hanging or timing out until others have been released.

11.4.2.10 Saving the Configuration

When you want to save the configuration, click Save on the File menu.

11.4.2.11 Activating the Configuration

To activate the configuration, you must stop and restart the SNA Server service, as follows:

1. In the SNA Servers folder, select the server and then, on the Service menu, click Stop. In this example the server is 'SNASRVR'.

2. When the server status has gone to 'Inactive', click 'Start on the Services menu. The server should then go to 'Active' status.

When the server is active, the underlying connections will attempt to activate if the 'Activation Type' was defined as 'On Server Startup' or 'On Demand', as described in the section Configuring the Connection.

Connections configured for Incoming and Outgoing calls go to 'On Demand/Incoming' status when successfully activated. The connection goes to the 'Active' status when the first session is established or if activated manually by the administrator. This requires the remote peer's communications server and connections also to be started.

11.4.3 Connecting CICS Option to a Remote PC

You need to configure CICS Option to communicate with the remote PC. If you have the SNA Server to PC connection working, as described in the previous section, then the configuration of CICS Option and the remote PC should be simple.

The parameters that you require for configuring CICS Option to the remote PC are:

11.4.3.1 Defining a CICS Option Connection to a Remote PC

To define a CICS Option connection to the remote PC you need to:

1. Start Mainframe Express.

2. Load or define the project for the region that you want to communicate with the remote PC.

3. On the Tools menu, click CICS and then Resource Definition.

4. Press F7 =group resources.

5. Add or select a group to add your connection definition to. In this example it is 'CONNECT'.

6. When the group has been selected. press F9 =terminal/connection. Then press F3 =connection.

7. Enter the Connect id. by which the remote PC will be known to your local system. That is, the SYSID of the remote PC as used in SYSID() entry of the EXEC CICS statements or the 'System ID' as used in the resource definition. In this example it is 'REG2'.

8. Press F3 =add.

9. Tab to the Description field and optionally enter a description.

10. Tab to the Connection type field and enter LU6.2.

11. Tab to the LU alias field and enter the independent LU name for your PU. This was defined as the local control point name in the Connection Properties dialog. In this example it is 'SNASYS1'.

12. Tab to the Partner alias field and enter the APPLID of the remote CICS system. In this example it is 'SNASYS2'.

13. Tab to the Alias applid field and enter the APPLID of the local system as defined to the remote PC. In this example it is 'SNASYS1'.

14. Tab to the Mode table field and enter the mode table that SNA Server and the remote PC are going to use. In this example it is '#INTER'.

15. Tab to the Session maximum field and enter the maximum number of sessions between LU-LU pairs that CICS Option allows. Please note that the maximum supported number allowed by CICS Option is 5. In this example we use 005.

16. Tab to the Net name field and enter the network name of this CICS system. In this example it is 'REGION2'.

17. Press F10 =save to save the record.

The definition is shown in Figure 11-2:

Figure 11-2: Definition of Remote PC Connection

11.4.3.2 Including the Resource Group in the Startup List

Now you need to ensure that the resource group with the remote CICS system's definitions is included in the startup list, as follows:

1. Click the CICS tab on the Project View.

2. Right-click on CICS System to display the associated context menu.

3. Click Startup List to display the Startup List Configuration dialog box.

4. Check whether the group containing the remote CICS system's definitions is in the left-hand list of Groups in Startup List. If not:
   1. Select the group from the right-hand list.

   2. Click << Add to move it to the left-hand list.

   3. Click OK to confirm the move.

11.4.3.3 Inbound Communications

You now need to define transaction programs to the local SNA Server so that it knows how to invoke CICS Option. This is the same as for PC to Mainframe communication and is described in the section Defining Transaction Programs.

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