Mirror Catalog.xml internally and use it with DSU & iDRACs

Hi All -

I couldn't get below method to work for DSU based updates.

1. Download the Catalog.xml for PowerEdge server from downloads.dell.com/catalog
2. Parse it to obtain the download links for SoftwareComponents. I use wge with -x option whihc preserves the original path and creates same directory structure on internal repo. Create http repo for the same under "dsu.domain.com"
3. Next, change the "baseLocation=dsu.domain.com" in Catalog.xml and post the Catalog.xml to http repo as well.

When I run dsu  -p  --catalog-location=Catalog.xml  (suceeds and shows the updates available). But when I run with -u to apply updates, it fails to download the packages.

Questions

1. Does DSU download over http or ftp? 

2. Is this method supported? We have over 3000 servers and would like to avoid having it download from ftp.dell.com everysingle time.

 PS: I am aware of the tools like OME, DRM etc for deploying updates, but this seems pretty simple to do  than login and use GUI.

Thanks!