Network Topology (SAP Library - Network Integration Guide (BC-NET))

Network Topology

As already described in the section Basics of SAP Communication, an SAP System communicates using server communication and access communication.

There is no standard solution for access communication (client access or access methods using external systems). You must find an appropriate network topology to access the R/3 Server depending on the type and number of clients, and particularly depending on the location of the system.

For server communication topology, you must first determine the location of the SAP server installation (database server and application server). The SAP System consists of one or several servers that are usually responsible for the entire enterprise and are located at a central point, the computer center. This is a centralized concept (as with mainframes) and is an advantage for maintenance and operation. Numerous clients that are widely spread out access these servers.

The concept of a "server farm" is well suited to SAP Systems.

Note the following basic principles:

All servers are connected to each other directly with a high bandwidth and minimal delay times. Switches are well suited for this.

If the servers are connected using shared media (for example, the Ethernet), there may easily be temporary network overloads, called collisions. Since this lowers performance, we recommend that you use an additional, separate network segment to connect the servers of an SAP System.

If you connect the R/3 Server with the campus or backbone network, you need routing functions. You can use routers or modern layer 3 switches (OSI Layer 3 = network layer).

By creating redundant network paths, you can protect your system against failure.

If the network topology covers several SAP Systems, the server connections should only include those servers of one system only so that optimal performance is ensured for each SAP System.

Network Topology for Switched Networks

If the R/3 Servers are connected using switches, access to the individual servers has a high and constant bandwidth. The connection between two servers has a minimal delay time.

Therefore, you only need to connect the servers of an SAP System to each other with an additional network adapter and switch if there is extremely high throughput and bandwidth requirements (for example, if the throughput of the network adapter is not sufficient). (See SAP System 1).

Network Topology for "Old Style" Shared Media Networks

For the SAP servers, you need a connection with a high bandwidth with minimum delay times. Shared media networks can contribute to this only partially. Communication between servers may lead to conflicts and network overloads. In this case, we recommend an additional network segment that connects the servers of an SAP System. We also recommend that you use a switch to connect the servers (see SAP System 1) rather than a shared media connection (see SAP Systems 2 and 3).