Named Data Networking

1. Multimedia & Mobile Communications Lab. Taejoong Chung 2010-03-21 tjchung@mmlab.snu.ac.kr Named Data Networking

2. Contents • Introduction • Vision • Architecture • Principle & Operation • Architecture Details • Name • Security • Routing and Forwarding • Caching, PIT • Transport • Conclusion

3. The Advent of Network • Networking was invented for sharing resources not for data • A user connects to server to use resources in machines • The fundamental communication model is point-to-point (host-to-host) conversation • Basically ‘Who/Where’ Model

4. Evolution of Network • However, overwhelming use of today’s network is for a machine to acquire chunk (data) • Acquire named chunks of data is not a conversation • It’s dissemination • Most of us need ‘WHAT’ data are, don’t care ‘WHERE’ it comes from • Middleware does it for us, the location of data is stored

5. Need for New Network • Data communication today is about moving content • Internet was moving dozens of exabytes/month. • IP datagram can only name communication endpoints • Current network-architecture is not appropriate for current usage • Propose an new internet architecture by removing this restriction: NDN

6. Architecture Principle • Hourglass architecture • ‘thin waist’ has been a key enabler for internet’s explosive growth • Security is built into the architecture • By signing all named data • cf) current network supports secure container • Traffic must be self-regulated • Flow-control is moved into network • Routing and forwarding plane separation • Similar to current one

7. NDN Architecture • Component • Messages • Interest • Data • FIB (Forwarding Information Base) • Similar to routing table • PIT (Pending Interest Table) • Store interests for data • Content Store • Space for cached data

8. NDN Basic Operation Interest MMLAB.kr/member/tjchung/ profile/v/s0 MMLAB.kr/member/tjchung/profile/v/s0 DATA:/ MMLAB.kr/member/tjchung/ profile/v/s0 MMLAB.kr/member/tjchung/profile/v/s0 0 /MMLAB.kr 1

9. NDN Supports • Automatically support various functionality without extra infrastructure • Content Distribution • Many users requesting the same data at different time • Multicast • Many users requesting the same data at same time • Mobility • User request data at different location • Delay-Tolerant Networking • Data is cached close to user

10. Architecture 1) Name • Names are opaque network • Router doesn’t know the meaning of the name • Allows each application to choose the name scheme that fits its need • Hierarchically structured name • Do not need to be globally unique • To retrieve dynamically generated data, it needs • Deterministic algorithm between consumer and producer • Partial name supports • mmlab/profile/tjchung -> mmlab/profile/tjchung/v0/1

11. Architecture 2) Security • Function of HOW rather than WHERE • Security is can not ‘opt-out’ but mandatory • Every data carries a signature • Data publisher information enables provenance • Current internet security cares about container (e.g. IPSEC)

12. Architecture3) Routing and Forwarding • Routes and forward packets on name, which eliminates • 1) Address space exhaustion • Unbound namespaces • 2) NAT traversal • Host doesn’t expose its address • 3) Mobility • No longer breaks communication since data name remain same • 4) Scalable address management • Address assignment & management is no longer required in local network

13. Architecture3) Routing and Forwarding (contd.) • Routing can operates in same way as before • Instead of IP prefix, using ‘Named’ prefix • Longest prefix match • Benefits • No open-loop problem • Random number added method for interest, reverse path for data • Enable to send interest to multiple interface without worries • Load balancing • Security • Signing all data prevents them from being spoofed • mitigates prefix hijacking • Difficult to send malicious packets to particular target

14. Architecture 4) Caching • Both IP & NDN router buffers data packet • But NDN router reuse data • Benefits • Both of static and dynamic data could be got benefits • In case of dynamic data, retransmission cost is eased • Alleviation of privacy problem concerns • In today’s network, one can figure out WHAT data is, WHO wants data from by inspecting header • NDN router doesn’t know who originates the request

15. Architecture 5) PIT (Pending Interest Table) • Waiting list for requiring data • Supports • PIT can setup timer (application takes charge of retransmission) • Natural support for multicast • Repetitive interest can be served using one data • Rate & Congestion control for incoming data • By controlling PIT size • Congestion control has been moved from transport layer • Mitigates DDoS attack • Number of PIT entries is an explicit indication of router loads

16. Architecture 6)Transport • NDN doesn’t have separate transport layer • Supports • Multiplexing and demultiplexing • Directly done using names • Data integrity and reliability checked • Signature • Management of traffic loads by setting PIT size • Eliminates end-host’s congestion control • Retransmission is aided by cache data congested clients server

17. On-Going Projects originated from limits • Routing table management • Unbounded address rises scalability issues for routing table • Security issues about key • Key management and dissemination • Cache capacity • Lots of cached space needed

18. Conclusion • Current usage of network needs changed paradigm from host centric to data centric network • We need data, not host information • NDN (Named Data Networking) supports many functionalities that is hardly or can not be done in current network • Addressing problem • Security problem • Etc..