i-1 Internet Intro Taekyoung Kwon

Internet Background Era of Cold War –Sputnik in > ARPA, NASA Government sponsored goal –Department of Defense (DoD) To maintain communication via computers even with threat of war –No central authority –Designed to operate while some systems are broken 2

Another motivation Na ï ve researchers 3 ARPA -> Defense Advanced Research Projects Agency (DARPA)

Paradigm shift Circuit switching → Packet Switching –data to be transmitted is divided into small packets of information and labeled to identify the sender and recipient –sent over a network and then reassembled at their destination –if any packet did not arrive or was not intact, original sender is requested to resend the packet 4

Context When Packet Switching was proposed –Packet Switching is a new idea telco gave it a -5 on a scale of 1-10 –Computers are million dollar items and ARPA can’t buy new ones every year but minicomputers have just arrived –Time-sharing and inter-process communication are new ideas –Personal Computers don’t exist –Networks are expensive 5

The Internet is born in Enable sharing of supercomputer power 4 nodes –UCLA –Stanford (SRI) –UC Santa Barbara –U of Utah Including BBN, some say 5 nodes

Zoom in to UCLA 7 Interface Message Processor

1972: Robert Kahn 8

2000s: middle-age Now it faces problems 9 IP TCP UDP Applications token radio, copper, fiber PPP Eth IP “hourglass” IP TCP UDP Applications token radio, copper, fiber PPP Eth diffserv intserv mcast mobile NAT IPSEC Expanding waist?

Internet standardization Protocol: a set of rules governing communication between hosts or devices 10 3GPP, IEEE

11 Now around 1B hosts! But count only hosts with domain names Internet hosts

Network prefixes 12 Source: bgp.potaroo.net

13 Traffic breakdown Cisco: By 2013 Video Will Be 90 Percent Of All Consumer IP Traffic And 64 Percent of Mobile

Environment: trusted → untrusted Requires a far more secure Internet –What do we mean by security? –What aspects are the network’s responsibility? Major design challenges: –Resilience to large-scale external attacks (DDoS) –Resilience to compromised routers –Easy authentication of data –Forensics and auditing –Providing both accountability and privacy 14

users: researchers → customers Customers demand high availability –Service is almost never interrupted Internet was designed for strong recovery properties –Recovering from serious failures How can the Internet provide 5 9’s of availability? –and doing so in a cost-effective manner –Internet currently at 2-3 9’s 15

operators: nonprofit → commercial Operators must be able to manage their networks –Configuration –Troubleshooting –Middleboxes (proxies, firewalls, NATs, etc.) –Policy (routing, access control) What are the right abstractions for management? –What mechanisms best support them? 16

usage: host-oriented → data- oriented Internet was designed around a host-oriented model –User tells client to contact another host (telnet, ftp) Current usage is mostly data-centric –User wants to access particular data or service –Does not care where that service is located Mismatch currently handled by ad hoc mechanisms –Akamai, P2P Right abstractions for a data-oriented Internet? 17

connectivity: e2e IP → intermittent Architecture assumes end-to-end IP connectivity In some niche settings, each link is intermittent and end-to-end connectivity is rare –Space, underwater, developing economies –Led to call for “delay-tolerant networking” (DTN) More generally want to shield applications from networking details –Opportunistic and context-dependent communication What’s the right API to enable this generality? 18

New requirements Mobility Scalability (e.g. network prefixes) Traffic Explosion (Especially wireless) Multicasting/Broadcasting Security Delay tolerant networks (DTNs) –E.g. vehicular ad hoc networks (VANETs) Multimedia, realtime applications –Video Adaptation –QoS, QoE Data center network Cyber physical system (CPS) E-911 –Should be able to disseminate emergency info –Spatial distribution 19