7
Configuring the Communications Interfaces

Communications between the Oracle Transparent Gateway for IBM DRDA and the DRDA server system use either the SNA Advanced Program to Program Communication (APPC/LU6.2) protocol or the Transmission Control Protocol/Internet Protocol (TCP/IP) protocol. Solaris system support for APPC is provided by the SunLink SNA Peer-to-Peer product. Solaris system support for TCP/IP is provided by the IBM TCP/IP product. Read this chapter to learn more about creating server profiles and configuring TCP/IP for DRDA.

This chapter contains the following sections:

Checklist for Configuring the Communications Interfaces

Step 1: Setting up a Gateway Name

The gateway name plays an important role in the use of the SunLink SNA Peer-to-Peer software. The gateway name is how users of SunLink SNA Peer-to-Peer client programs (for Oracle, it is the Oracle gateway kernel) identify the gateway.

After you decide on a gateway name on your Sun host, you can define it in one of two ways:

Method 1:

Use NIS/NIS+ to create the gateway name in the NIS/NIS+ database. Refer to the SunLink SNA Peer-to-Peer RunTime System Administrator's Guide for an example.

Method 2:

Use a flat file, /etc/appc, to define the gateway name in your workstation.

For example, enter:

sunlinkgtw  sunhost:sunlinkgtw

where:

sunlinkgtw is the gateway name.

sunhost is the hostname of the Sun workstation.

Step 2: Setting up a Configuration File

To enable communication between a SunLink SNA Peer-to-Peer gateway and a remote SNA host, you must specify (in SNA terms) the precise configuration of a SunLink SNA Peer-to-Peer gateway on your Sun host. The information is contained in a flat ASCII file, ./appc.

For SunLink SNA Peer-to-Peer Version 9.0, this ./appc file is input to the sunpu2.1 utility.

The input file has the form of verbs with associated parameters. Each of the verb identifiers corresponds to an Application Programming Interface (API) verb. Depending on the hardware configuration of your SNA network, this input file might have different verbs and parameters.

Refer to the SunLink SNA Peer-to-Peer Runtime and System Administrator's Guide for a detailed description of each verb in the input file and its associated parameters.

A sample SNA configuration file for SunLink SNA Peer-to-Peer Version 9 is shipped with the gateway. After you have successfully installed the Oracle Transparent Gateway for IBM DRDA, you can find it in the tg4drda/sna subdirectory. The sample file is:

$ORACLE_HOME/tg4drda/sna/SunLink9.cfg, for sunpu2.1 configuration connecting the Sun host to several IBM hosts

Also shipped with the gateway are sample Side Information Files. They are also located in the tg4drda/sna subdirectory as outlined in the following list:

$ORACLE_HOME/tg4drda/sna/DB251ALU, a Version 9 sample Side Information File
$ORACLE_HOME/tg4drda/sna/DB2V23LU, a Version 9 sample Side Information File
$ORACLE_HOME/tg4drda/sna/DRDA400, a Version 9 sample Side Information File
$ORACLE_HOME/tg4drda/sna/DB2VM51, a Version 9 sample Side Information File

Starting the SNA Peer-to-Peer Version 9 Software

To start the SunLink SNA Peer-to-Peer Version 9 software, start the gateway by issuing the command:

sunpu2.1 -f ./appc

where ./appc is the name of the configuration file.

Step 3: Side Information File

Before starting an APPC conversation with a partner program, a CPI-C program requires certain information. This information, known as side information, is provided by the Side Information File. The symbolic destination name corresponds to an entry in the Side Information File containing the Partner_LU_name, Mode_name, and TP_name.

Partner_LU_name

This identifies the name of the remote, or partner LU associated with the DRDA server. In addition to specifying the fully qualified partner LU name, you can also specify a partner LU alias to identify a partner LU location profile (if required).

To allow more than one concurrent conversation between the gateway and the DRDA server, specify that parallel sessions are supported in this profile.

Mode_name

This must be defined in the IBM DRDA server communication software. IBM DRDA servers use the mode name IBMRDB in many DRDA examples, but this is not required. Choose the mode name and the other mode parameters after consulting the person responsible for configuring the IBM DRDA server-side communications software. The mode_name you specify must exist at the target DRDA server. It does not need to be defined in the same SNA gateway.

The parameters, related to parallel session limits, play a role in determining the maximum number of concurrent conversations allowed between a gateway instance and the IBM DRDA server. This equates to the maximum number of open database links using the gateway instance.

TP_name

This generally identifies the program to be executed on the server side of an APPC conversation. IBM DRDA uses a special reserved TPN (called an SNA Service Transaction Program) that is expressed in hexadecimal because it contains non-printable characters. The TPN for DB2/MVS, DB2/UDB, and DB2/400 is X'07F6C4C2'.

For DB2/VM, the DRDA server does not use the standard DRDA TPN. Instead, the TPN identifies the VM Resource ID (RESID) of the target DB2/VM server virtual machine, and can be non-hexadecimal characters. The RESID is specified when DB2/VM is configured.

Specifying the Side Information File

Any CPI-C transaction program which issues the Allocate call must specify the Side Information File through the environment variable, CPIC_SI. The CPI_C library looks for the CPIC_SI variable when the CMINIT procedure call is made.

Sample Side Information File for Version 9

The name of the Side Information File for Version 9 must be specified in the Gateway Initialization File initsid.ora as:

DRDA_CONNECT_PARM=/oracle/tg4drda/side9/DB2V23LU

Enter the value in the Appendix E, "Configuration Worksheet".

Here is a sample Side Information File for SunLink SNA Peer-to-Peer Version 9.0:

PTNR_LU_NAME = DB2V23
MODE_NAME    = IBMRDB
TP_NAME      = x'07F6C4C2'

Step 4: Test the Connection

Before proceeding with the installation and configuration of the Oracle Transparent Gateway for IBM DRDA, test that your connection is working. For instructions on testing this connection, refer to the SunLink SNA Peer-to-Peer RunTime System Administrator's Guide.

Figure 7-1, "Relationship of SunLink SNA Definitions to Host VTAM Definitions" shows the relationship between the SunLink SNA Peer-to-Peer definitions and the VTAM definitions on the host.

Figure 7-1 Relationship of SunLink SNA Definitions to Host VTAM Definitions

Text description of the illustration ch7a.gif

Configuring TCP/IP

Basic configuration consists of assigning a Hostname, an IP Address, and a Network Mask to a given network interface.

Additional configuration consists of defining a Name Server IP Address or creating entries in the Hosts file on the local machine. Name Servers translate hostnames into IP Addresses when queried on a particular host name. The Hosts file provides this same functionality, but in a non-network participating manner.

For local configuration (i.e., the gateway and the DRDA server are on the same machine), it may be desirable to use the loop-back address. The IP address is 127.0.0.1 and is typically given the local name ("localhost" or "loopback") in the Hosts file. Using the loop-back address reduces the amount of network overhead by handling the traffic internally without actually talking to the network.

The gateway is configured for TCP/IP using the DRDA_CONNECT_PARM initialization file parameter. In an SNA configuration, this parameter would be set to the Side Information Profile name. In a TCP/IP configuration, this parameter should be set to the IP address or Host name of the DRDA server, which should be followed by the Service Port number of that server.

Note:

When installing the gateway, you must choose either SNA or TCP/IP for the Networking Interface. The DRDA_CONNECT_PARM must be configured correctly for the chosen Networking Interface.

The rest of the DRDA-specific parameters are unrelated to the communications protocol and may be set the same for either SNA or TCP/IP installations, as illustrated below.

Example #1:

Configuration for a DRDA server on a host named 'mvs01.domain.com' (or IP address of 192.168.1.2) with a Service Port number of 446.

DRDA_CONNECT_PARM=mvs01.domain.com:446

DRDA_CONNECT_PARM=192.168.1.2:446

Example #2:

Configuration for a DRDA server on the same host as the gateway with a Service Port number of 446.

DRDA_CONNECT_PARM=localhost:446

DRDA_CONNECT_PARM=127.0.0.1:446

For additional information on configuring TCP/IP, refer to your Oracle9i Installation Guide for Sun SPARC Solaris 2.x.

7 Configuring the Communications Interfaces