That IP Address belongs to Apple. You can usually find out 'who' any IP address 'is' by using
http://whoisip.org or even the "Whois" tab in Network Utility. If you ever upgrade to
Yosemite or
El Capitan , you might want to make an alias of Network Utility for your regular "Utilities" folder. The actual app resides in /System/Library/CoreServices/Applications/. Part of Apple's grand-motherly hiding of anything they thing we might hurt ourselves with!
Port 1638x is simply the port that is used to communicate between your computer and "Apple". Once you find Network Utilities, you can use the "Port Scan" tab, enter you computers IP address (Check your System Prefs->Network (if using Ethernet) or ->Sharing (select "DVD Sharing" or "Screen Sharing" Service and the IP address should appear in the text below the 'Xyz Sharing: On'.
I'd suggest contacting the Lil' Snitch devs for an explanation. These kinds of reports are exactly why I quit using it. YMMV.