Today we will just look at the two examples
The main point being to show especially how the transmission of multiple media streams, as in the second example, involves two twisted pairs (RTP/RTCP combinations) and thus required 4 ports.
The example RFCDatabase is one I will not have occasion to cover formally in class, but presents a tool, and especially a result, that might be very useful for you. The result is a CSV database (the separator is the "bar" character "|") that can be used directly or imported into any database known to mankind. It helps keep track of the approximately 5000 RFC documents.