Software Download information utilized by all Zhone devices in order to obtain software images on to local storage. In lower-end devices, the download itself may be stored directly into a boot area which is automatically used upon restart of the system. The login/password information may be ignored if the device only supports tftp. Sets to these fields will be accepted so the request may continue.
Sources for this description
Multiple manufacturers; see the original MIB MIB copies (LibreNMS/Observium Community)