Ok, so I'm pretty sure they mean "Package" and not "Packet" but there is a great article by David Leibowitz (the SQL guy, not the pastry chef) on designing modular SSIS packages on the Simple-Talk web site - check it out here: http://www.simple-talk.com/content/article.aspx?article=500.
I've long been a proponent of the "one table per package" design pattern in SSIS, but I've never seen such a coherent and comprehensive writeup online that covers both what to do and why to do it. I don't know if I agree with everything that David has to say, but all in all it's a good read with downloadable code as well. Make sure you check it out.
 Yeah, it's not much as design patterns go, but I do think that it qualifies.