The udc10.02.120.iso (or udc10.02.120_legacy.iso) file in the installation directory for UDC3 is a so-called hybrid image. It can not only be copied onto USB storage devices but can also be used to create a bootable DVD.
Burn ISO image (Windows)
Burn ISO image (Linux)
Under Linux, various burning programs with a graphical user interface or for the command line are available.
The Ubuntu Wiki explains how to burn an ISO image onto a DVD using a number of programs.