Connecting to a specific application server

To connect to a specific application server, you enter strings which, according to the complexity of the networks, might be more or less complex and contain passwords to secure the routers.

In its basic form, a connection string consists of the host name (or IP name) of an SAP application server; for example: 
/H/hemlock.romlab.rome.abc.com
This type of connection string works only in very simple network environments, where all application servers can be reached directly through TCP/IP. Usually, modern companies use more complex network topologies, with a number of small subnetworks, which cannot communicate directly through TCP/IP. To support this type of network, the SAP RFC library supports SAP routers, which are placed at the boundaries of the subnetworks and act as proxies. For this type of network, the connection string is a composite of basic connection strings for each SAP router, followed by the basic connection string for the target SAP system; for example: 
 /H/litespeed/H/amsaix33/H/hemlock.romlab.rome.abc.com

Moreover, you can secure the SAP routers with passwords, to prevent unauthorized access. In this case, the basic connection string for the SAP router is followed by /P/ and the password of the router.

Note: The SAP RFC library limits the length of the connection string to a maximum of 128 characters. This is a real limitation in complex network environments. As a workaround, it is recommended to use simple host names, without the domain name whenever possible. Alternatively, you can use the IP address, but this is not recommended, because it is difficult to maintain.
HCL Workload Automation for SAP supports both types of connection strings, basic and composite, where:
r3host
The connection string.
r3instance
The SAP instance number.
r3sid
The SAP system ID.
For example: 
r3host=/H/litespeed/H/amsaix33/H/hemlock.romlab.rome.abc.com
r3instance=00
r3sid=TV1