After installing the Ironstream package, each subsequent PTF includes all pre-requisites since package “SDF21AA”. You can download the latest ZEN, DCE, IDT, SDF, or SDK co-requisite components separately; they are included in the Ironstream package but they might not be the latest PTF if they were shipped separately from an SDF component fix.
You can quickly find the latest component PTFs in Knowledge Base section of the Precisely Support website (support.precisely.com) by using the Keyword search field to enter one of the 3-character component identifiers followed by an asterisk. For example, to find the latest DCE PTFs, enter “DCE*”, then sort the results by “Published On (Latest First).