Client/Server Communication

SAP ASE communicates with other SAP ASE servers, Open Server™ applications (such as Backup Server), and client software on your network. Clients communicate to one or more servers, and servers can communicate with other servers using remote procedure calls.

For SAP products to interact with one another, each product needs to know where the others reside on the network. Names and addresses of every known server are listed in a directory services file. This information can be stored in a directory services file two different ways:

After your SAP ASE or client software is installed, it can connect with any server on the network that is listed in the directory services.

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 directory services 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, Open Server, or Backup Server to which they want to connect. It also tells the server where to listen for incoming connection attempts from clients. The server uses a single port for these two services (referred to as query service and listener service).

During installation, you use the srvbuild utility to create and configure a new server. The srvbuild process adds entries to the interfaces file for your new SAP ASE, Backup Server, and XP Server.

For instructions about how to modify existing interfaces file entries using dsedit and dscp, see the Utility Guide.

Related concepts
Use the Lightweight Directory Access Protocol as a Directory Service