The DRDA database protocol
Applications can use the Distributed Relational Database Architecture™ (DRDA) protocol to control remote access.
With DRDA, the application connects to a server at another location and executes packages that have been previously bound at that server. The application uses a CONNECT statement, a three-part name, or an alias to access the server.
Queries can originate from any system or application that issues SQL statements as a requester in the formats required by DRDA.
For two-phase commit using Systems Network Architecture (SNA) connections, Db2 supports both presumed abort and presumed nothing protocols that are defined by DRDA. If you are using TCP⁄IP, Db2 uses the sync point manager that is defined in the documentation for DRDA Level 3.