Download randomly failed

Hi, actually we use Dell Ome with Official repository downloads.dell.com/catalog/catalog.gz. But download of firmware (in update task) randomly failed : Error while Downloading the file. Firmware cannot continue Task Failed. Completed With Errors. And if I test many time, on same server, 1 time can failed and 5 minutes after can success. Do you have an explication? Regards, Shugotek