1. Jang, Donghyun 2011/4/4 dhjang@mmlab.snu.ac.kr 1/21

2.  Introduction  System overview  CNF Protocol details  Performance summary  Conclusion 2/21

3.  Representative Future Internet research project ◦ NSF FIND and GENI in the U.S. ◦ FP7 Future Networks and FIRE in Europe  This paper presents the initial results of an NSF FIND project  The initial results focus on designing a clean- slate network architecture for efficient delivery of media content to mobile users 3/21

4.  ~2.5 billion cell phones vs. ~500 million wired PC  Smart phones and PDA proliferate rapidly  The number of Internet transactions from mobile devices may be expected to surpass those from wired network PC’s over the next 5-10 years ◦ Shift of end-users from wired to mobile 4/21 VS

5.  Internet usage pattern ◦ Communication => contents service (delivery of large file)  Need next-generation Internet protocol service optimized to support media content delivery to mobile user 5/21

6.  Existing Internet protocols (e.g., TCP/IP) are not well-suited for mobile content services  TCP model assumes a contemporaneous source-to-destination path ◦ Mobile users experience intermittent and unreliable access over wireless channels  TCP model was originally designed to support point-to-point data services ◦ It is not suitable for multipoint content dissemination 6/21

7.  To solve the problems of TCP/IP architecture ◦ Facilitate opportunistic transport on a hop-by-hop basis rather than end-to-end streaming of data  Hop-by-hop transport model implies large in-network storage (cache) of content files  This is basic idea of the cache-and-forward (CNF) network architecture 7/21

8.  Each node has a large storage cache  CNF router may either be wired or wireless, also mobile (especially, mobile CNF router refer to Cache and Carry (CNC) router) 8/21 CNC

9.  Network serves two functions ◦ Pull: Mobile end-user can request contents ◦ Push: Content provider can push the content to one or more end-users 9/21

10.  When mobile end-user can request contents ◦ Contents Discovery  copies of the same content can be cached in multiple CNF routers in the network  Discover the CNF router with the desired content that is “closest” to the requesting endpoint 10/21 S Content

11. When content provider can push the content  Post Office (PO)  Edge of the wired core network  Holding and forwarding point for content to mobiles 11/21 PO

12. 1.The sender contacts a name resolution service that resolves the name of the mobile host to a set of PO nodes 2.The sender will forward the file to one or more PO’s using conventional point-to-point routing 3.These PO’s will “hold” the file until contacted by the mobile host to arrange delivery 12/21

13.  Each query and content file is carried as a CNF packet data unit or package in a hop- by-hop fashion 13/21

14.  Implemented as overlay network on IP network 14/21

15.  A link in the CNF architecture is a logical link between two adjacent CNF nodes  Consists of two components ◦ Link Session Protocol (LSP) ◦ Link Transport Protocol (LTP)  The choice of LTP will depend on the characteristics of the link 15/21

16.  Content discovery ◦ Content-aware routing based on a content identifier (CID)  Routing content after content was discovered ◦ Conventional (IP) address-based routing 16/21

17.  Fragment very large files (10’s of GB) into smaller chunks (~100MB-1GB) before transporting 17/21 End-host

18.  Name Resolution Service (NRS) ◦ Map the name of an endpoint to its corresponding POs  File Name Resolution Service (FNRS) ◦ Map a CID (content identifier) to corresponding attributes of the content  Attributes of the content  Content Hash, Content Creator, Content Access Rights, etc 18/21

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20.  Simulation by using ns2  Hop-by-hop vs. TCP performance ◦ TCP is better than hop-by-hop in low load ◦ Hop-by-hop is better than TCP in high load  Wireless multi-hop performance ◦ The results show that significant throughput gains are possible with customized link layer protocols like CLAP instead of TCP  Content routing gains ◦ Reduction of content retrieval time and traffic load 20/21

21.  New approach to network design in response to growing needs for improved support for both mobility and content in the future internet  The design presented here is clearly preliminary and will be further refined 21/21