PPJ-01 Introduction

PPJ-01 SDN Introduction
http://eueung.github.io/EL5244/
Software Defined Networking

Transcript

1. PPJ #1 Virtualization & Software Defined Networking http://eueung.github.io/EL5244/ Dr.-Ing. Eueung Mulyana | 2015H2
2. This material is mainly a derivative and remix work. Most of the texts and illustrations are taken from the talks/lectures given by these networking professors/gurus/ninjas: Scott Shenker, Nick McKeown, Jennifer Rexford, Mike Freedman, Nick Feamster, Guido Appenzeller, Marco Cello, Li Erran Li.
3. The State of Networking
4. The Internet: A Remarkable Story • Tremendous success – From research experiment to global infrastructure • Brilliance of under-specifying – Network: best-effort packet delivery – Programmable hosts: arbitrary applications • Enables innovation – Apps: Web, P2P, VoIP, social networks, … – Links: Ethernet, fiber optics, WiFi, cellular, …
5. Key to Internet Success: Layers Applications …built on… …built on… …built on… …built on… Reliable (or unreliable) transport Best-effort global packet delivery Best-effort local packet delivery Physical transfer of bits
6. Why Is Layering So Important? • Decomposed delivery into fundamental components • Independent but compatible innovation at each layer • A practical success of unprecedented proportions… • …but (also) an academic failure
7. Inside the ‘Net: A Different Story… • Closed equipment – Software bundled with hardware – Vendor-specific interfaces • Over specified – Slow protocol standardization • Few people can innovate – Equipment vendors write the code – Long delays to introduce new features
8. Do We Need Innovation Inside?
9. Built an Artifact, Not a Discipline • Other fields in “systems”: OS, DB, DS, etc. – Teach basic principles – Are easily managed – Continue to evolve • Networking: – Teach big bag of protocols – Notoriously difficult to manage – Evolves very slowly
10. Do We Need Intellectual Progress? • Lots of domain details – Plethora of protocols – Heaps of header formats – Big bunch of boxes – Tons of tools • Teaching networking – Practitioners: certification courses, on the job – Undergraduates: how the Internet works
11. Why Does Networking Lag Behind? • Networks used to be simple: Ethernet, IP, TCP…. • New control requirements led to great complexity – Isolation  VLANs, ACLs – Traffic engineering  MPLS, ECMP, Weights – Packet processing  Firewalls, NATs, middleboxes – Payload analysis  Deep packet inspection (DPI) • Mechanisms designed and deployed independently – Complicated “control plane” design, primitive functionality – Stark contrast to the elegantly modular “data plane”
12. Infrastructure Still Works! • Only because of “our” ability to master complexity • This ability to master complexity is both a blessing… – …and a curse!
13. What Is the problem? • Networking still focused on mastering complexity – Little emphasis on extracting simplicity from control plane – No recognition that there’s a difference…. • Extracting simplicity builds intellectual foundations – Necessary for creating a discipline …. – That’s why networking lags behind
14. On the Other Side … • Machine languages: no abstractions – Mastering complexity was crucial – Had to deal with low-level details • Higher-level languages: OS and other abstractions – File system, virtual memory, abstract data types, ... • Modern languages: even more abstractions – Object orientation, garbage collection,… Abstractions  key to extracting simplicity
15. Problem & Solution Enter SDN
16. Why was a good Solution needed? • Networks are hard to manage • Networks are hard to evolve • Networks design not based on formal principles
17. Hard to Manage • Networks are still notoriously hard to manage – Network administrators large share of sysadmin staff • Computation and storage have been virtualized – Creating a more flexible and manageable infrastructure – Need skills to manage virtualized assets
18. Hard to Evolve • Ongoing innovation in systems software – New languages, operating systems, etc. • Networks are stuck in the past – Routing algorithms change very slowly – Network management extremely primitive
19. Lacking on Formal Principles • OS courses teach fundamental principles – Mutual exclusion and other synchronization primitives – Files, file systems, threads, and other building blocks • Networking courses teach a big bag of protocols • No formal principles, just general design guidelines
20. Lacking on Formal Principles • Networks used to be simple – Basic Ethernet/IP straightforward, easy to manage • New control requirements have led to complexity – ACLs, VLANs, TE, Middleboxes, DPI,… • The infrastructure still works... – Only because of our great ability to master complexity • Ability to master complexity both blessing and curse
21. On the Other Side … (again) • Machine languages: no abstractions • Higher-level languages: OS and other abstractions • Modern languages: even more abstractions Abstractions simplify programming Easier to write, maintain, reason about programs Abstractions are the way we extracted simplicity So, what role do abstractions play in networking?
22. The Two Networking Planes • Data plane: processing and delivery of packets with local forwarding state – Forwarding state + packet header  forwarding decision • Control plane: compute the state in routers (forwarding state) – Determines how and where packets are forwarded – Routing, traffic engineering, firewall state, … – Implemented with distributed protocols, manual configuration (and scripting) or centralized computation • These different planes require different abstractions
23. Remember … • Networks used to be simple: Ethernet, IP, TCP…. • New control requirements led to great complexity – Isolation  VLANs, ACLs – Traffic engineering  MPLS, ECMP, Weights – Packet processing  Firewalls, NATs, middleboxes – Payload analysis  Deep packet inspection (DPI) • Mechanisms designed and deployed independently – Complicated “control plane” design, primitive functionality – Stark contrast to the elegantly modular “data plane”
24. (Too) Many Control Plane Mechanisms • Variety of goals: – Routing: distributed routing algorithms – Isolation: ACLs, VLANs, Firewalls,… – Traffic engineering: adjusting weights, MPLS,… • No modularity, limited functionality • Control Plane: mechanism without abstraction – Too many mechanisms, not enough functionality
25. TL;DR • Networking is “Intellectually Weak” • Networking is behind other fields • Networking is about the mastery of complexity • Good abstractions tame complexity • Interfaces are instances of those abstractions • No abstraction => increasing complexity • We are now at the complexity limit
26. Software Defined Networking: An Illustration
27. Software Defined Networks control plane: distributed algorithms data plane: packet processing
28. Software Defined Networks decouple control and data planes
29. Software Defined Networks decouple control and data planes by providing open standard API
30. Software Defined Networks Controller Platform
31. Software Defined Networks Controller Platform Controller Application
32. Why is SDN Happening? An Industry Perspective (Guido Appenzeller)
33. Closed & Proprietary Networking Equipment Vertically Integrated Systems Have Changed Little Over the Past 15 Years
35. Contrast with Server Equipment Open Architecture – Choice of Vendors – Innovation Velocity – Low TCO
37. Evolution of Server Provisioning 1996-2013 Server provisioning has made huge gains through automation.
39. Evolution of Network Provisioning 1996-2013 Network provisioning has not evolved.
41. Compute Evolution Networking Evolution SSH
42. What do these switches have in common?
47. Virtual Infrastructure Networking, Services, Storage, Compute
49. Credit • Scott Shenker, The Future of Networking and the Past of Protocols • Nick McKeown, Stanford University, Many Talks/Articles • Jennifer Rexford, COS 597E, Princeton University • Mike Freedman, COS 461, Princeton University • Nick Feamster, https://www.coursera.org/course/sdn • Li Erran Li, COMS 6998-10, Univ. of Columbia • Marco Cello, SDN Talk @ CNR, Univ. Genova • Guido Appenzeller, Network Virtualization in Multi- tenant Datacenters, VMware