Using connection strings for SAP GUI

Background

Qualibrate records a “Connect to SAP” step when opening a new SAP GUI connection thru the SAP LogonPad. During the recording process, Qualibrate will extract the details of the connection normally by identifying the server name and system number of the SAP environment.

To support advanced server configurations, Qualibrate allows to use other connection details such as the standard SAP connection strings. The documentation below is the official article from the SAP support site, and provides information on how to build connection strings that are fully supported by Qualibrate.

Connection Strings

Connection String is a technical term used within SAP GUI. A connection string describes a connection address for a destination, e.g. an SAP system's application server, similar to an Internet URL describes a location for a web page.

Simple Connection Strings

In its simplest form, a connection string contains an IP address and a port number. This information is sufficient for SAP GUI to open a direct TCP connection to a destination, e.g. an application server. IP address and port number are marked with the prefixes '/H/' (for host) and '/S/' (for service). Note that the port number for an SAP application server is by convention 3200 plus the two-digit SAP system number.

If your network environment supports DNS (Domain Name Services), a hostname can be used instead of the IP address in all kinds of connection strings. (This requires a correct DNS configuration on the client, e.g. via the hosts file).

If your network environment supports symbolic service names for well-known ports, the symbolic service name can be used instead of the port number in all kinds of connection strings. (This requires a correct service configuration on the client, e.g. in the services file). Note that SAP application server ports are by convention named 'sapdp<SID>', where <SID> is the SAP system id

Simple connection strings need not to be resolved by the SAP GUI application. Resolution of host names and symbolic service names is done by the operating system's network layer.

SAP Routers

In a WAN (Wide Area Network) environment, SAP routers are used to make connections to remote SAP systems that cannot be reached with a direct TCP connection. Passwords may be used for each SAP router to control access. In order to make a connection, the client is responsible for providing the complete route to the destination, possibly including a chain of several SAP routers. Path information is not provided by the routers. (Strictly speaking, an SAP router is actually better described as an application level proxy with password capabilities and strict source routing). The address for each router is specified by a simple connection string (with the router's host name and port number), optionally followed by '/P/' and the router password. The path from the current location to the destination is described by concatenating all router addresses, followed by the address of the destination SAP system. Thus, a connection string with SAP routers generally has the form <router 1><router 2>...<router n><destination>.

Connection strings including SAP routers are passed to SAP GUI's communication layer and resolved step by step by the routers on the path. If host names and symbolic service names are used, each router must have access to correct network configuration information to resolve them.

Message Servers and Logon Groups

For load balancing purposes, application servers from one SAP system are usually configured in logon groups, where each group serves a particular kind of user. The application servers in each group are assigned to users by a least-heavily-loaded strategy. This load balancing is done by message servers. Each SAP system has exactly one message server, which can be reached via TCP on a specific message server port.

Message server and group information can be used to address an SAP system in a connection string. The address of the message server is specified as a combination of message server host name, message server port and group name. This information is marked with the prefixes '/M/'(message server host name), '/S/' (message server port) and '/G/' (logon group).

Connection strings with message servers are resolved by SAP GUI by contacting the message server and retrieving the (simple) connection string of an application server for the specified group. This requires network access to the message server at the time the address is resolved. SAP router connection strings may be used in combination with message server connection strings simply by specifying the router address before the message server address. The router is then used for contacting the message server as well as for contacting the resolved application server.

Symbolic System Names

The most user-friendly form of connection string addresses an SAP system only by its symbolic name (per convention, the system id) and the logon group name. This information is marked with the prefixes '/R/' (for the symbolic SAP system name) and '/G/' (for the logon group name).

Formal Syntax

For the technically interested reader, the following BNF grammar formally describes the syntax of connection strings:

Sample Code

<connection string> := [<router prefix>]<local>
<local> := <simple>|<message server>|<symbolic>
<simple> := "/H/"<host>"/S/"<service>
<host> := <hostname>|<ipaddr>
<hostname> := (any DNS hostname)
<ipaddr> := (any IP address, in dotted decimal form)
<service> := <servicename>|<port number>
<servicename> := (any IP service name)
<port number> := (any decimal number)
<messageserver> := "/M/"<host>"/S/"<service>"/G/"<group>
<group> := (any ASCII string not containing '/')
<symbolic> := "/R/"<system>"/G/"<group>
<system> := (any ASCII string not containing '/')
<router prefix> := <router>*
<router> := "/H/"<host>"/S/"<service>["/P/"<password>]
<password> := (any ASCII string not containing '/')