This is a radio show by Steve Gibson (the 'I' in the quotes below) and Leo Laporte
How the Internet Works, Part 2 http://grc.com/securitynow.htm
During this 38-minute, part 2 episode of "How the Internet Works," Leo and I briefly review last week's discussion of the ICMP protocol, then discuss the operational details of the Internet's two main data-carrying protocols: UDP and TCP.
How the Internet Works, Part 1
During this 49-minute episode, Leo and I briefly discuss the 'Kama Sutra' virus that will become destructive on February 3rd. We briefly discuss PC World Magazine's recent evaluation and ranking of ten top anti-malware systems. And we begin our long-planned 'fundamental technology' series with a two-part close look at the history and detailed operation of the global Internet.
you can listen to it online.