1. The Future of the Internet Jennifer Rexford ’91 Computer Science Department Princeton University http://www.cs.princeton.edu/~jrex

2. 2 The Internet: A Remarkable Story Tremendous success –From research experiment to global communications infrastructure The brilliance of under-specifying –Best-effort packet delivery service –Key functionality at programmable end hosts Enabled massive growth and innovation –Ease of adding hosts and link technologies –Ease of adding services (Web, P2P, VoIP, …) But, change is easy only at the edge… 

3. 3 Rethinking the Network Architecture But, the Internet is showing signs of age –Security, mobility, availability, manageability, … Challenges rooted in early design decisions –Weak notion of identity, tying address & location –Not just a matter of redesigning a single protocol Revisit definition and placement of function –What are the types of nodes in the system? –What are their powers and limitations? –What information do they exchange?

4. 4 Hurdle #1: Deployment Dilemma An unfortunate catch-22 –Must deploy an idea to demonstrate feasibility –Can’t get an undemonstrated idea deployed A corollary: the testbed dilemma –Production network: real users, but can’t change –Research testbed: easy changes, but no users Bad for the research community –Good ideas sit on the shelf –Promising ideas do not grow up

5. 5 Hurdle #2: Too Many Design Goals Many different system-engineering goals –Scalability, reliability, security, privacy, robustness, performance guarantees, … –Perhaps we cannot satisfy all of them at once Applications have different priorities –Online banking: security –Web surfing: privacy, high throughput –Voice and gaming: low delay and loss Compromise solution isn’t good for anyone

6. 6 Hurdle #3: Coordination Constraint Difficult to deploy end-to-end services –Benefits only when most networks deploy –No single network wants to deploy first Many deployment failures –QoS, IP multicast, secure routing, IPv6 –Despite solving real, pressing problems Increasing commoditization of ISPs senderreceiver 123

7. 7 Virtualization to the Rescue Multiple customized architectures in parallel –Multiple logical routers on a single platform –Isolation of resources, like CPU and bandwidth –Programmability for customizing each “slice”

8. 8 Overcoming “Deployment Dilemma” Multiple experimental networks in parallel –Some are mature, offering services to users –Isolated from others that are works in progress VINI: VIrtualized Network Infrastructure –Virtual nodes, links, and network stack in Linux –Deployed in Internet2 and National Lambda Rail

9. 9 Overcoming “Too Many Design Goals” Run multiple operational networks in parallel –Customized to certain applications and users Programmable network elements –Virtualized kernel-level packet handling –Using Click, Linux IP chains, NetFPGA Design of customized protocols –Protocols as distributed solutions to optimization problems –E.g., delay vs. throughput sensitive

10. 10 Overcoming “Coordination Constraint” Run multiple end-to-end services in parallel –Infrastructure providers: Maintain routers, links, data centers, etc. –Service providers: Offer end-to-end services (e.g., layer 3 VPNs, SLAs, etc.) to users Infrastructure ProvidersService Providers

11. 11 Conclusion The Internet needs to change –Security, mobility, availability, management, … We can overcome barriers to change –Realistic experimentation with new ideas –Multiple designs with different trade-offs –End-to-end deployment of new services Network virtualization is the key –Run many research experiments in parallel –Offer customized end-to-end services in parallel