Reading on"The Design Philosophy of the DARPA Internet Protocols"

This paper discussed some designing objects and principles for the Internet in 70s and captured some of the early reasoning which shaped the Internet protocols. The author deeply discussed the reasons for three goals about survivability, types of service and varieties of networks. The survivability is the first objective of Internet design. The reason for splitting TCP and IP is because of the requirement for supporting diversity of services.
But till now in the Inter-domain routing, survivability is still challenging. Link failure or node failure will lead to transient interruption of communication of two ASes. So, I do think inter-domain multipath routing needs to be paid more attention.
How many questions do we have about the original Internet? we can all find the answers in this paper.
I also found something common between this paper and "end to end" paper about the voice application.