SNA connections to LAN protocols

You or the system can connect Systems Network Architecture (SNA) to a LAN protocol by using one or more service access points (SAPs).

Multiple SAPs allow you to have multiple connections between SNA and a LAN protocol, thus permitting multiple communication paths between independent applications.

You or the system specifies the SAPs to use in the line and controller descriptions. For SNA, the system can automatically create one SAP value (the default value). There might be cases where you want to change this value or have additional SAPs:

• The remote system does not use the default source service access point (SSAP).
• You want parallel station-to-station connections between adapters. This might be what you want if you link two applications that require different controller descriptions.
• You want station-to-station connections to the same adapters. You might want to do this to configure multiple SAPs to test an application on a single system.

If you plan to change the SAP defaults, see your SAPs for guidelines and other information.

SSAP and DSAP:

Local SAPs are known as source service access points (SSAPs). The remote SAPs are known as destination service access points (DSAPs). Your system sends data from a SSAP to a DSAP.

• Your SNA service access points
  If you decide to change the default Systems Network Architecture (SNA) service access points (SAPs) or add more SAPs, you must define them in the line and controller descriptions.