SAP ASE communicates with other SAP ASE servers, Open Server applications (such as Backup Server), and client software on your network. Clients can interact with one or more servers, and servers can communicate with other servers by remote procedure calls.
For SAP products to interact with one another, a directory services file must list the names and addresses of every known server. This information can be stored in either:
After your SAP ASE or client software is installed, it can connect with any server on the network that is listed in the interfaces file or in the LDAP server.
When you are using a client program, and you want to connect with a particular server, the client program looks up the server name in the interfaces file and connects to that server. You can supply the name of the server by using the DSQUERY environment variable.
On TCP/IP networks, the port number gives clients a way to identify the SAP ASE to which they want to connect. It also tells SAP ASE where to listen for incoming connection attempts from clients. SAP ASE uses a single port for these two services (referred to as listener service query service).
On SPX networks, the socket number gives clients and servers a way to identify each other.
The installer adds entries to the sql.ini file for the new SAP ASE, Backup Server, or XP Server.