Lecture 2 Protocol Stacks and Layering Dejian Ye Software School Fudan University Networking, Spring 2009
1 Lecture 2 Protocol Stacks and Layering Dejian Ye Software School Fudan University Networking, Spring 2009
Last time The Big picture y Goas Efficiency ilities"(scalability, manageability, availability) 3 Ease of creating applications 》 Challenges: Scale Geography Heterogeneity(** today' s focus A few specific details: 》 Circuits vs. packets >)Little bit about routing > Service model and how to construct services today !)
2 Last Time The Big Picture » Goals: – Efficiency – “ilities” (scalability, manageability, availability), – Ease of creating applications » Challenges: – Scale – Geography – Heterogeneity (** today’s focus!) A few specific details: » Circuits vs. packets » Little bit about routing » Service model and how to construct services (** today!)
Todav's Lecture ast time: "Big picture"(Design meeting system goals) Today >)General architectural principles for networks (Design for imlementation) >) Introduces a few concrete models examples Where we are going: >) Socket programming rev iew++ (for project >)Application examples( still high level) >)After that: Burrowing into the details, ground up Today' s specifics 》 What is a protocol 》 Protocol stacks 》 Some history > Standards organizations. 》 Application layer
3 Today’s Lecture Last time: “Big picture”(Design meeting system goals) Today: » General architectural principles for networks(Design for imlementation) » Introduces a few concrete models & examples Where we are going: » Socket programming review++ (for project) » Application examples (still high level) » After that: Burrowing into the details, ground up Today’s specifics: » What is a protocol. » Protocol stacks. » Some history. » Standards organizations. » Application layer
Why protocols and layering? No one can im plement such a huge system only by himself, and the system need to accommodate technology evolution, so we need the following >)Interoperability 》 Reuse >) Hiding underlying details Distributed components collaborate together, so > Some kind of agreement and collaboration between computing and communicaiton nodes
4 Why protocols and layering? No one can implement such a huge system only by himself, and the system need to accommodate technology evovlution. so we need the following: » Interoperability » Reuse » Hiding underlying details Distributed components collaborate together, so » Some kind of agreement and collaboration between computing and communicaiton nodes
What is a Protocol An agreement between parties on Friendly greeting how communication should take place. Protocols may have to define many aspects of the Muttered repl communication Syntax ) Data encoding, language, etc. Semantics. > Error handling, termination, ordering of Destination? requests, etc Protocols at hardware, software all levels! Shanghai Syntax: English, ascii, lines delimited by“ln Different layer protocol, e.g different communication method Thank you when a human grow up
5 What is a Protocol An agreement between parties on how communication should take place. Protocols may have to define many aspects of the communication. Syntax: » Data encoding, language, etc. Semantics: » Error handling, termination, ordering of requests, etc. Protocols at hardware, software, all levels! Syntax: English, ascii, lines delimited by “\n” Different layer protocol, e.g., different communication method when a human grow up Friendly greeting Muttered reply Destination? Shanghai Thank you