All we (support analysts) can do is give the best informaiton we can for the right audience, if it can't be understood by either party then communication has to happen. If you don't know jargon, interrupt and ask. It is that simple.
The "dumbin' it down approach" as a default is wrong because a) you are assuming the person you are talking to is a numpty and below your level of understanding (you're being arrogant [sic]) and b) you are problably giving them information that they cannot process anyway.
You don't tell a business person that they can't save their documents to a shared network drive becuase there is a NAT configuration problem. You tell them that there is a networking issue preventing from saving their documents and that you have to contact their network administrator (or if you are the netadmin) and tell them that you should have a resoloution by date blah (pending further issues) and you'll have detailed information available should they want it.
Support is 20% fixing problems and 80% keeping people happy (at all levels).