DTT files were used by IBM AS/400 severs first released in 1988. DTT format is no longer is use. AS/400 servers, when they were popular, used DTT files for saving data transfer information.

AS/400 servers were mostly used by medium and larger business. The server machines were praised for their stability and efficient system solutions. AS/400 was powered by PowerPC CPU and ran under OS/400 operating system. DTT files were utilized by systems administrators for system performance analysis purposes.