The Internet: An Exciting Time One of the most influential inventions –A research experiment that escaped from the lab –… to be a (the?) global communications infrastructure Ever wider reach –Today: 2 billion users –Tomorrow: more users, computers, sensors, content Constant innovation –Apps: Web, P2P, social networks, virtual worlds –Links: optics, WiFi, cellular,... 1

Transforming Everything The ways we do business –E-commerce, advertising, cloud computing,... The way we have relationships – , IM, Facebook friends, virtual worlds How we think about law –Interstate commerce? National boundaries? Wikileaks? The way we govern –E-voting and E-government –Censorship and wiretapping The way we fight –Cyber-attacks, including nation-state attacks 2

But what is networking?

A Plethora of Protocol Acronyms? BGP ARP HTTP DNS PPP OSPF DHCP TCP UDP SMTP FTP SSH MAC IP RIP NAT CIDR VLAN VTP NNTP POP IMAP RED ECN SACK SNMP TFTP TLS WAP SIP IPX STUN RTP RTSP RTCP PIM IGMP ICMP MPLS LDP HIP LISP LLDP BFD 4

A Heap of Header Formats? 5

TCP/IP Header Formats in Lego 6

A Big Bunch of Boxes? Router Switch Firewall NAT Load balancer DHCP server DNS server Bridge Hub Repeater Base station Proxy WAN accelerator Gateway Intrusion Detection System Packet shaper Route Reflector Label Switched Router Scrubber Packet sniffer Deep Packet Inspection 7

An Application Domain?

Application Domain for Theory? Algorithms and data structures Control theory Queuing theory Optimization theory Game theory and mechanism design Formal methods Information theory Cryptography Programming languages Graph theory

Application Domain for Systems? Distributed systems Operating systems Computer architecture Software engineering …

What Peers in Other Fields Say “What are the top ten classic problems in networking? I would like to solve one of them and submit a paper to SIGCOMM.” After hearing that we don't have such a list: "Then how do you consider networking a discipline?” “So, these networking research people today aren't doing theory, and yet they aren't the people who brought us the Internet. What exactly are they doing?” “Networking papers are strange. They have a lot of text.” Is networking a problem domain or a scholarly discipline?

“There is a tendency in our field to believe that everything we currently use is a paragon of engineering, rather than a snapshot of our understanding at the time. We build great myths of spin about how what we have done is the only way to do it to the point that our universities now teach the flaws to students (and professors and textbook authors) who don't know better.” -- John Day (Internet pioneer)

Before you all leave …

So, Why is Networking Cool? Relevant –Can measure/build things –Can impact the real world Interdisciplinary –Well-motivated problems + rigorous solution techniques –Interplay with policy and economics Widely-read papers –Many of the most cited papers in CS are in networking –Congestion control, distributed hash tables, resource reservation, self-similar traffic, multimedia protocols,… –Three of top-ten CS authors (Shenker, Jacobson, Floyd)

Ecosystem Deployments in R&E Networks Interest from providers/data center operators Vendors Commitment varies

Architectural questions tend to dominate CS networking research

Today’s Divisions of Labor End host and the network –Packet switching –Best-effort delivery –Fixed end-points with IP addresses Protocol layers –IP as the center of the universe –IP above the link layer –IP below transport and application network UDPTCP Data Link Physical Applications

Beyond Today’s Division of Labor

Software Router PC + Multi-Port NIC

Difficult to develop, always behind industry Difficult to program, constrained environment Too expensive Custom Hardware

Between Hosts and the Network Networked services hosted in data centers –Web sites, social networks, video streaming, online gaming, virtual worlds,... –Replicated on servers in multiple data centers –Churn from mobile users, migrating VMs, failures, … Time to rethink –Naming and addressing –Server and network load balancing –Energy usage –End-host network stack and socket API. clients servers data centers Internet

Vertically integrated Closed, proprietary Slow innovation Small industry Specialized Operating System Specialized Operating System Specialized Hardware Specialized Hardware App Specialized Applications Specialized Applications Horizontal Open interfaces Rapid innovation Huge industry Microprocessor Open Interface Linux Mac OS Mac OS Windo ws (OS) Windo ws (OS) or Open Interface

Vertically integrated Closed, proprietary Slow innovation App Horizontal Open interfaces Rapid innovation Contr ol Plane Contr ol Plane Contr ol Plane Contr ol Plane Contr ol Plane Contr ol Plane or Open Interface Specialized Control Plane Specialized Control Plane Specialized Hardware Specialized Hardware Specialized Features Specialized Features Merchant Switching Chips Merchant Switching Chips Open Interface

Software Defined Network (SDN) Global Network View Network Virtualization Packet Forwarding Packet Forwarding Packet Forwarding Packet Forwarding Packet Forwarding Packet Forwarding Packet Forwarding Packet Forwarding Packet Forwarding Packet Forwarding Network OS Abstract Network View Control Programs Control Programs

Broader interest in an evolvable Internet

Cellular industry Recently made transition to IP Billions of mobile users Need to securely extract payments and hold users accountable IP sucks at both, yet hard to change

Telco Operators Global IP traffic growing 40-50% per year End-customer monthly bill remains unchanged Therefore, CAPEX and OPEX need to reduce 40-50% per Gb/s per year But in practice, reduces by ~20% per year

Scott Shenker at 1 st ONS in 2011 “The Future of Networking and the Past of Protocols”

29