What is an open system and how does it foster interoperability? Compare and contrast proprietary and open systems. What is the seven-layer logical breakdown of network interaction called? What is a...

What is an open system and how does it foster interoperability? Compare and contrast proprietary and open systems. What is the seven-layer logical breakdown of network interaction called? What is a protocol stack and why is it layered? What constitutes the foundation of Internet communication? What is the role of the IP protocol?