Chapter 2: outline 2. 1 principles of 2.6 P2P applications network 2.7 socket applications programming with 2.2 Web and Http UDP and TCP 2.3 FTP 2 4 electronic mail SMTP POP 3 IMAP 25 DNS Application Layer 2-2
Application Layer 2-2 Chapter 2: outline 2.1 principles of network applications 2.2 Web and HTTP 2.3 FTP 2.4 electronic mail ❖ SMTP, POP3, IMAP 2.5 DNS 2.6 P2P applications 2.7 socket programming with UDP and TCP
Chapter 2: application layer our goals: D learn about protocols o conceptual by examining popular implementation application-level aspects of network proTocols application protocols 令HTTP .o transport-layer .. FTP service models , SMTP/POP3/ IMAP ☆ client- server . DNS paradigm O creating network o peer-to-peer applications paradigm ☆ socket apt Application Layer 2-3
Application Layer 2-3 Chapter 2: application layer our goals: conceptual, implementation aspects of network application protocols ❖ transport-layer service models ❖ client-server paradigm ❖ peer-to-peer paradigm learn about protocols by examining popular application-level protocols ❖ HTTP ❖ FTP ❖ SMTP / POP3 / IMAP ❖ DNS creating network applications ❖ socket API
Some network apps 口e-mdi o voice over Ip(e.g g web Skype) o text messaging g real-time video D remote login conferencing o P2P file sharing 口 social networking g multi-user network search games o streaming stored video D Cou Tube, hult Netf×) Application Layer 2-4
Application Layer 2-4 Some network apps e-mail web text messaging remote login P2P file sharing multi-user network games streaming stored video (YouTube, Hulu, Netflix) voice over IP (e.g., Skype) real-time video conferencing social networking search … …
创建一个网络应用 编写分布式程序,使得可以 运行在不同的端系统上 令通过网络相互通信 例如,web服务器软件与浏览 器软件 不需为网络核心设备写程序 冷网络核心设备不运行用户 应用 在端系统上开发应用有利 network dato 于应用的快速研发和部署 SICa Application Lo
2: Application Layer 5 创建一个网络应用 编写分布式程序，使得可以 ❖ 运行在不同的端系统上 ❖ 通过网络相互通信 ❖ 例如，web服务器软件与浏览 器软件 不需为网络核心设备写程序 ❖ 网络核心设备不运行用户 应用 ❖ 在端系统上开发应用有利 于应用的快速研发和部署 application transport network data link physical application transport network data link physical application transport network data link physical
211网络应用架构 口网络应用架构规定了在各个端系统上组织应用 程序的方法: 客户-服务器架构( Client- server) 冷对等架构(Peer-to-peer,P2P) Application Lo 6
2: Application Layer 6 2.1.1 网络应用架构 网络应用架构规定了在各个端系统上组织应用 程序的方法： ❖ 客户-服务器架构（Client-server） ❖ 对等架构（Peer-to-peer ，P2P)