SDN Use-Cases. internet exchange, home networks. TELE4642: Week8. Materials from Prof. Nick Feamster is gratefully acknowledged

Transcription

1 SDN Use-Cases internet exchange, home networks TELE4642: Week8 Materials from Prof. Nick Feamster is gratefully acknowledged

2 Overview n SDX: A Software-Defined Internet Exchange n SDN-enabled Home Networks 8-2

3 8-3

4 IXP: Internet Exchange Point n n n A physical infrastructure through which Internet Service Providers (ISPs) and content Delivery Networks (CDNs) exchange Internet traffic between their networks (autonomous systems: AS) AS: a collection of IP prefixes under control of single administrative entity that presents a common routing policy to the Internet Internet traffic exchange between two participants on an IXP is facilitated by Border Gateway Protocol (BGP) routing Participants announce routes via the peering relationship either routes to their own addresses, or routes to addresses of other ISPs that they connect to 8-4

5 Internet Exchange Map 8-5

6 IXP ISP 1 CDN 1 AS1 AS4 switch fabric ISP 2 ISP 3 AS2 AS3 8-6

7 Limitation of BGP n n n n Routing only destination IP prefix no customisation of routes by application, sender Influence only over immediate neighbors no ability to affect end-to-end paths Indirect expression of policy indirect mechanisms to influence path selection (e.g., local preference, AS path prepending) Enables only basic packet forwarding difficult to introduce new in-network services 8-7

8 Valuable Wide-Area Services n n n n n Application-specific peering Route video traffic one way, and non-video another Blocking denial-of-service traffic Dropping unwanted traffic further upstream Server load balancing Directing client reuests to different data centers Steering through network functions caches, crypto, IDS,.. Inbound traffic engineering Splitting incoming traffic over multiple peering links 8-8

9 SDN opportunities n Opportunities: freedom from constraints matching of different packet headers (not just destination IP address) control messages from remote networks (not just immediate neighbors) using a single program direct control over data plane (not indirect control via routing protocols arcana) perform many different actions on packets (beyond basic packet forwarding) 8-9

10 Deploy SDN at Internet Exchanges n Leverage: New technology at a single IXP can yield benefit to hundreds of providers without providers deploying new euipment! n Innovation hotbed: Incentives to innovate, as IXPs on front line of peering disputes n Growing in numbers: IXPs ~100 new IXPs established in past few years 8-10

11 Conventional IXPs IXP BGP session AS 1 Router Route server switching fabric BGP session AS 2 Router AS 3 Router 8-11

12 SDX = SDN + IXP SDX BGP session SDX controller BGP session AS A Router SDN switch AS B Router AS C Router 8-12

13 Prevent DDoS Attacks AS1 under attack originating from AS3 Attacker AS 3 SDX 1 SDX 2 AS 2 AS1 can remotely block attack traffic at SDX(es) AS 1 Victim 8-13

14 DDoS protection: SDX-based vs. Conventional n Remote influence Physical connectivity to SDX not reuired n More specific Drop rules based on multiple header fields (src IP, dst IP, port number, ) n Coordinated Drop rules can be coordinated across multiple IXPs 8-14

15 Inbound Traffic Engineering SDX AS A Router AS B Router C1 C /8 AS C Routers 8-15

16 Inbound Traffic Engineering AS A Router Incoming data AS B Router C1 C /8 AS C Routers fine grained policies not possible with BGP SDN enables fine-grained traffic engineering policies incoming traffic out port using BGP using SDX dstport = 80 C1? match (dstport=80), fwd(c1) 8-16

17 Building SDX is challenging n Programming abstractions How networks define SDX policies and how are they combined together? n Interoperation with BGP How to provide flexibility without breaking global routing? n Scalability How to handle policies for hundreds of peers, half million address blocks, matches on multiple header fields? 8-17

18 Virtual Switch Abstraction Switching Fabric virtual switch virtual switch A1 AS A match(dstport=80)èfwd(c) virtual switch AS C AS B B1 C1 C2 match(dstport=80)èfwd(c1) n Each AS writes policies for its own virtual switch 8-18

19 Combining Participant s policies Switching Fabric virtual switch virtual switch A1 AS A AS B B1 P virtual switch AS C P C1 C2 n Synthesizes: match(inport=a1 & dstport=80) è fwd(c1) 8-19

20 SDX Conclusion n The Internet is changing new challenges for content delivery increasing importance of IXPs n SDN can let providers innovate 8-20

21 6-21

22 Home Networking: Two Challenges n Providing users with visibility into usage and problems in the network n Providing controls to help users better manage resources, usage caps, etc. 8-22

23 Too much complexity is exposed 8-23

24 Lack of visibility and control n Indivisible usage how much do I have left? when will I run out? n Mysterious processes what application are getting us capped? can I limit these? n Multiple users who is getting us capped? share out bandwidth? 8-24

25 SDN: Centralised, outsourced control Content Providers cloud-based service manager UI / app API Controller db user 1 Internet Internet ISP #1 Broadband access link ISP #2 user 2 Home #1 Home #2 Home gateway n Users monitor behavior and set policies via UserInterface/app [ITNAC 15] Third-party Customization of Residential Internet Sharing using SDN 8-25

26 Two applications of SDN control n Home network management example of outsourced home network management enables remote control, better UI n Slicing home network virtualizing network infrastructure to allow content providers direct access 8-26

27 Key problem: Usage Control 8-27

28 NetworkSeer: discovery (active/inactive) 8-28

29 NetworkSeer: live usage! 8-29

30 Historical usage 8-30

31 Quota management n How to limit a device/user? 8-31

32 Parental monitoring 8-32

33 Slicing Home Networks: two-sided control n Many content providers want to offer high uality services to home users (e.g. Video providers) [TNSM 16] SDN APIs and Models for Two-Sided Resource Management in Broadband Access Networks 8-33

34 Dynamic / Static Fast-lanes 8-34

35 Static Fastlane Control POST /os/subsid "mac":<mac>,"bw":<bw> 8-35

36 Home Networks Conclusion n Home networks can be difficult to manage users have limited visibility and control content providers have limited access n Two applications of SDN in home networks usage monitoring and control slicing home networks 8-36