If I am looking at traffic from my network and I see (e.g., using SmartWhois) that a lot of user traffic is going to certain CDNs. e.g., in one network 87% of my traffic goes to Amazon. Is there a way to disaggregate this, even a little, to get a sense of what all of this traffic means? 

I see that certain popular Web sites are located on certain CDNs (e.g., click the CDN names on the legend of this chart: <a href="http://www.datanyze.com/market-share/CDN/?goback=%2Egde_38181_member_223489435">CDN Market Share</a>) but matching things up this way feels like I am simply guessing, particularly with Amazon -- the CDN market leader. 

I was wondering if certain CDN clients might be assigned certain IP addresses within the CDN block -- I thought that someone else might have come up with a lookup table or a database for sale, but I can't find anything like that by googling, so maybe that is not a viable approach.

I currently only have easy access to the IP address that flows are going to. With that data, is disaggregating this CDN traffic further impossible?  If I know it is not possible I will stop looking.

Many thanks in advance for any help!