See Switched 56.
(1) (Directory Server Agent) An X.500 program that looks up the address of a recipient in a Directory Information Base (DIB), also known as white pages. It accepts requests from the Directory User Agent (DUA) counterpart in the workstation.
(2) (Digital Signature Algorithm) The algorithm used in the Digital Signature Standard (DSS) by the U.S. government. The de facto standard RSA algorithm is more widely used than DSA.
(3) (Digital Storage Architecture) A disk controller standard from Digital.
(4) (Digital Signal Analyzer) A Tektronix oscilloscope that samples high-frequency signals.
(5) (Distributed Systems Architecture) A network architecture from Bull Worldwide.