1 ICN research work 27 th September, 2012 Suyong Eum

2 Problems and ICN Problems we have nowICN solution A. Multiple identical requests.A. Network level response. B. No optimization of traffic.B. Optimization of content dissemination. C. No Intelligent service provider.C. Caching near to the end users. D. Bursty traffic by “Flash-crowd”.D. Localizing bursty traffic. E. Client side mobility support.

Which problems? At last, ICN is about how to handle information objects. How to distribute them in the network? How to locate them on request? NumbersComments & reference Size of BGP RT 4.5*10 5 How many routes can an up-to-date BGP router handle at maximum? + α [bgp.potaroo.net] DONA10 11 Back in 2007, that number of data objects could be supported easily. Domains4.6*10 7 Routing with domain names? [ Indexed web pages 5*10 10 Google’s indexed web pages [ Indexed URLs10 12 Google’s indexed URLs back in 2008 [ How many?10 15 That is the number of information objects what people generally(?) believe ICN is supposed to support. Copies at caches? Scaling by 10 or 100 x (?) How many copies are expected per content in ICN? 3

How to distribute information objects? On-path cachingOff-path cachingReplication Implicit distributionImplicit/Explicit distribution Explicit distribution Dynamic & volatileDynamicStatic Reactive pullReactive pushProactive push Which node on the path and how it is selected? Local decision, cache or not. How many and where to push the information object? CCNx, symmetric path.DHT style, non- symmetric path. CDN style The replication and off-path caching mechanisms have been intensively studied in the context of CDN and web caching. Since ICN is generally assumed that it leverages its in-network storage, the on-path caching mechanism is a quite interesting approach. 4

On-path caching? 5

How to locate an information object? Name based routingName resolution approach High control-overhead.An additional system required, e.g., a name resolution infrastructure. Simplification the overall process.Comparable to current Internet. Intelligence in the network.Intelligence in the resolution system. On-path cachingOff-path caching/replication Push mechanism?Push/Pull mechanism CCNx, DONA.NetInf, PSIRP. We are using the name based routing called PBR (Potential Based Routing). 6

2. Potential based approach – how does it work? Close and good quality but congested Close but poor quality Far but good quality ? ? Potential Based Routing (PBR) 7

PBR: h ow to create a potential field?  Blue dot line  Black dot-dashed line =>Potential field from n p1 =>Potential field from n p2  Red solid line =>Potential field that are linearly summed from both potential values. Ψ(n): potential value at node “n”. N: the number of nodes which have the content j. Q: Expected quality of the content. dist: distance between node “n” and “n j ” with content j. δ: attenuation factor. 8

PBR: as a main routing mechanism Top: a potential field is fully defined within an area (intra or inter domain) for an original content. Middle: a potential field is defined within a limited scope (one or two hops from caching points). Bottom: a potential field which is linearly combined above two fields. Thus, while the ball representing a user request moves down to ``A" which represents the location of the originally published content file, it is attracted to ``B" which shows the location of the copied one in the cache. 9

PBR: as a subsidiary best-effort routing Potential Based RoutingBreadcrumb Routing Best-effort routing Active routingPassive routing Selective ads? Self scaling? Self management? 10

A power law topology (N=1000, E=2000) A content file is located on a randomly chosen node. -The node floods an ads-message within a limited area (m: hops). PBR with random-walk 11

Wait! 2.2 longer than SPR? Relative Delay Coverage (%) # of caching nodes (%) m=1 m=2 m=1 12

In a different size network (m=2)? 13

Some discussions Some research works….. On-path caching algorithms. Potential field corresponding to a bloomfilter. Probabilistic routing. ICN with SDN. 14