The ISO Template is a type of template that is specifically reserved for ISOs that can be used to boot a VSI. ISO Templates are available in two versions: public and private. Public ISO Templates are preconfigured templates provided by SoftLayer that can be used by any customer. Private ISO Templates are created by importing an image of an ISO stored on an Object Storage Account. In order for an ISO to be imported to the Image Templates screen, the ISO must be bootable.
At this time, only SoftLayer Supported Operating Systems can be used to load an ISO Template onto a VSI. A list of Supported Operating Systems can be found here: http://www.softlayer.com/services/software/