SNA Server 3.0 Supports Multiple Connections to Same AS/400

• Microsoft SNA Server, version 3.0

SUMMARY

Microsoft SNA Server, version 3.0 can be configured to have multiple APPN-capable connections to the same AS/400. Previous versions of SNA Server did not support multiple APPN-capable connections to the same AS/400.

For additional information on why SNA Server 2.x did not support multiple APPN-capable connections to the same AS/400, please see the following article in the Microsoft Knowledge Base:

   ARTICLE-ID: Q131625
   TITLE: Multiple APPN-capable Connections to Same AS/400 Not Supported

MORE INFORMATION

For SNA Server to connect to an AS/400, an APPC controller definition must exist for SNA Server's local control point name. The APPC controller may be autocreated by the AS/400 or manually created by the AS/400 administrator.

The AS/400 allows only a single APPC controller, with a given control point name, over any line it supports. Previous versions of SNA Server can only be configured with one local control point name. SNA Server, version 3.0 allows the local control point name to be overridden for each connection defined for a particular SNA Server. This allows multiple APPC controllers to be created for a single SNA Server.

The following is an example of two 802.2 connections to the same AS/400:

1. Install two DLC 802.2 Link Services via SNA Server Manager and configure each to use a different Local Service Access Point (SAP). The first DLC 802.2 Link Service can be setup to use the default local SAP of 0x4 and the second can be setup to use a local SAP of 0x8. For this example, we will call them SnaDlc1 and SnaDlc2.

2. Create and configure an 802.2 connection for the first connection to the AS/400 by selecting Insert -> Connection -> 802.2 from the Menu Bar in Manager. The AS/400 Wizard can also be used to create and configure the connection.

   Note: SNA Server 3.0 does not create connections for installed link services by default like the previous versions of SNA Server did. SNA Server Manager can be configured to automatically create connections when link services are installed by checking the Automatically Create Connections for New Link Services checkbox under View -> Options.

         Name = Enter a 1 to 8 character connection name.
         Link Service = SnaDlc1 (or the name of one of the link
                        services added in Step 1)
         Remote End = Peer System
         Allowed Directions = Outgoing Calls. Check Incoming Calls if
                              you want the AS/400 to activate the link.
         Activation = If set to "On Server Startup" (default), then the
                      Switched disconnect (SWTDSC) value on the AS/400
                      controller definition should be set to NO. This
                      causes the underlying link to stay active even if
                      there are no active sessions. Otherwise, if
                      SWTDSC is YES, then SNA Server should be set to
                      "On Demand" activation.
   
      Select the Address tab:
   
      Remote Network Address = The Ethernet or Token Ring MAC address of the
                               AS/400.
      Remote SAP Address = 0x4
   
      Select the System Identification tab:
   
      Local Node Name:
   
      Network Name = APPN (or Remote Network ID, RMTNETID value on the
                           AS/400).
      Control Point Name = This is the remote control point name (RMTCPNAME)
                           value in the AS/400 APPC controller definition.
                           This is set to the local Windows NT machine name
                           by default for all connections that are created.
                           For this connection use the default value, which
                           will be SNASERV1 for this example.
      Local Node ID = EXCHID value on the AS/400 controller description (if
                      not specified on the AS/400, leave at default - 05D
                      FFFFF).
   
      Remote Node Name:
   
      Note: The parameters in the Remote Node Name do not need to be
      specified for 802.2 connections.
   
      Network Name = APPN (or remote network ID RMTNETID value on the
                           AS/400).
      Control Point Name = AS/400 local control point name, configured in the
                           AS/400 Display Network Attributes screen.
      Remote Node ID = Not used (leave blank).
   
      Settings in the 802.2 DLC tab can be left at their default settings.
   
   

3. Create and configure the second 802.2 connection that will be used to communicate with the AS/400.

         Name = Enter a 1 to 8 character connection name. The name must
                be different from all other connections names on this
                SNA Server.
        Link Service = SnaDlc2 (The other link service that was
                       installed in Step 1).
        Remote End = Peer System
        Allowed Directions = Outgoing Calls. Check Incoming Calls if
                             you want the AS/400 to activate the link.
        Activation = If set to "On Server Startup" (default), then the
                     Switched disconnect (SWTDSC) value on the AS/400
                     controller definition should be set to NO. This
                     causes the underlying link to stay active even if
                     there are no active sessions. Otherwise, if
                     SWTDSC is YES, then SNA Server should be set to
                     "On Demand" activation.
   
      Select the Address tab:
     
         Remote Network Address = The Ethernet or Token Ring MAC address of the
                                  AS/400.
         Remote SAP Address = 0x8
   
      The Remote SAP Address for this connection needs to be set to a value 
      different than the value for the first 802.2 connection. The SAPs are 
      defined in the communications line description on the AS/400. Your
      AS/400 administrator can help you with this. Valid SAPs are configured
      in increments of 0x4 (in other words, 0x4, 0x8, 0xC, 0x10, and so forth).
      SAP 0x4 is configured by default on the AS/400.
   
      Select the System Identification tab:
   
         Local Node Name:
   
         Network Name = APPN (or Remote Network ID, RMTNETID value on the
                              AS/400).
         Control Point Name = SNASERV2 (Specify a value different than the one
                              used for the previous connection. Note: *** This
                              is the key parameter for allowing multiple APPN-
                              capable connections from a SNA Server to the same
                              AS/400. *** )
   
         Local Node ID = EXCHID value on the AS/400 controller description (if
                         not specified on the AS/400, leave at default - 05D
                         FFFFF).
   
         Remote Node Name:
   
         Note: The parameters in the Remote Node Name do not need to be
         specified for 802.2 connections.
   
         Network Name = APPN (or remote network ID RMTNETID value on the
                              AS/400).
         Control Point Name = AS/400 local control point name, configured in the
                              AS/400 Display Network Attributes screen.
         Remote Node ID = Not used (leave blank).
   
         Settings in the 802.2 DLC tab can be left at their default settings.
   
   

4. Create two Local APPC LUs for the SNA Server by selecting Insert -> APPC -> Local LU from the SNA Server Manager menu bar.

5. Create a Remote APPC LU for each connection to the AS/400 by selecting Insert -> APPC -> Remote LU from the SNA Server Manager menu bar. The Remote LU Alias will be different for each Remote LU, but the Remote LU Name will be the same for both Remote LUs.

   ARTICLE-ID: Q112158
   TITLE: Configuring SNA Server to Talk to AS/400 Over 802.2

   ARTICLE-ID: Q112159
   TITLE: Configuring SNA Server to Talk to AS/400 Over SDLC