1 Course Summary What have we learned: a huge amount! m principles m practice ….. using Internet to motivate examples

2 Chapter 1: Introduction Our goal: r get “feel” and terminology r more depth, detail later in course r approach: m use Internet as example Overview: r what’s the Internet r what’s a protocol? r network edge r network core r access net, physical media r Internet/ISP structure r performance: loss, delay r protocol layers, service models r network modeling

3 Chapter 2: Application Layer r conceptual, implementation aspects of network application protocols m transport-layer service models m client-server paradigm m peer-to-peer paradigm r learn about protocols by examining popular application-level protocols m HTTP m FTP m SMTP / POP3 / IMAP m DNS r web security r programming network applications m socket API

4 Chapter 3: Transport Layer r understand principles behind transport layer services: m multiplexing/demultipl exing m reliable data transfer m flow control m congestion control r reliable multicast r learn about transport layer protocols in the Internet: m UDP: connectionless transport m TCP: connection-oriented transport m TCP congestion control

5 Chapter 4: Network Layer r understand principles behind network layer services: m forwarding m routing (path selection) m dealing with scale m how a router works m advanced topics: IPv6 r instantiation in the Internet r broadcast, multicast routing

6 Chapter 5: The Data Link Layer r understand principles behind data link layer services: m error detection, correction m sharing a broadcast channel: multiple access ALOHA (slotted and unslotted) Ethernet m link layer addressing r Ethernet hubs and switches r link virtualization, brief introduction to ATM, virtual circuits r did not cover – PPP (5.7), MPLS (5.8.2), DHCP (5.4.3), Manchester Encoding (Figure 5.25) r do not expect you to remember CRC details

7 Chapter 6: Wireless & Mobile Networks Wireless r Wireless links, characteristics m CDMA r IEEE wireless LANs (“wi-fi”) r Cellular Internet Access m architecture m standards (e.g., GSM) Mobility r Principles: addressing and routing to mobile users r Mobile IP r Handling mobility in cellular networks r Mobility and higher- layer protocols

8 Chapter 8: Network Security r understand principles of network security: m cryptography and its many uses beyond “confidentiality” m authentication m message integrity m key distribution r security in practice: m firewalls m security in application, transport, network, link layers (WEP)

9 Chapter 7:Multimedia Networking Principles r making the best of best effort service m dealing with delay jitter and loss r mechanisms for providing QoS m e.g., leaky bucket, weighted fair queuing Protocols and Architectures r specific protocols for best-effort m e.g., RTP/RTCP, SIP r architectures for QoS (IntServ, Diffserv) r did not cover 7.1.4, – 7.2.3, 7.4.4, 7.5 (covered before mid-term), details of IntServ/Diffserv, Per-hop behavior, RSVP

10 Networked Systems Wireless LAN Mobile Adhoc Network Public Switched Telephone Network Internet Gateway Sensor Network Home Network Cellular Access Network voice data

11 Networking Applications r financial – stock trading, portfolio management r social – voice communication, , chat, telecommuting r entertainment - games, music, video, surfing r medical – telemedicine r…r… r networked systems indispensable part of not just global communication infrastructure but our daily lives

12 Q: Whither goest networking? A: nobody knows! General tends: r ubiquity of communications m IP dialtone, IP: like electricity: it’s everywhere! m network-capable appliances (e.g., IP toaster) m issues of scale important: 100's of millions of network- connected devices r mobility important: m people move, need to communicate r multimedia important: m it is how people communicate

13 Q: Whither goest networking? r increasing link rates, but bandwidth not free in near future m increased # "users" m increased bandwidth requirements of enabled apps r high bandwidth to home (DSL, cable modems) a major driver for future m games, VR, education, information, entertainment m merger of networking and telephony m broadcast entertainment (TV) and WWW r security, reliability, management: critical concerns

14 Our Very Last Note Page! r this course: m specific architectures, protocols m fundamental issues: APIs, reliable data transfer, flow/congestion control, routing, multiple access, addressing, security r remember: you learned it HERE!

15 Final Exam on 12/13/06 8:00 AM to 9:30 AM r Four parts m Part 0 – Name and course number – 1 point m Part 1 - Multiple choice questions (A – D) [No None of the above choice] ~ 32 points m Part 2 – Short Answer Questions ~ 5 points m Part 3 – (extra credit for cs5480) ~ 3 points r Closed book closed notes r Post midterm material (however, expected to know important pre-midterm concepts)