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Workshop at Space Internetworking Center (SPICE), Xanthi Delay Tolerant Networking and Content/Service-Centric Networking. Torsten Braun Universität Bern braun@iam.unibe.ch rvs.unibe.ch. Overview. Computer Networks and Distributed Systems @ U Bern
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Workshop at Space Internetworking Center (SPICE), XanthiDelay Tolerant Networking and Content/Service-Centric Networking Torsten Braun Universität Bern braun@iam.unibe.ch rvs.unibe.ch
Torsten Braun: Service-Centric Networking Overview • Computer Networks and Distributed Systems @ U Bern • Content- and Service-Centric Networking in Mobile and Delay-Tolerant Networks • Conclusions and Outlook
Torsten Braun: Service-Centric Networking Research Projects @ Computer Networks and Distributed Systems • Opportunistic Routing forHighly Mobile Ad-hoc Networks • Authentication, Authorization, Accounting, and Auditing in Wireless Mesh Networks (A4-Mesh) • Mobile/Wireless Content-Centric Networks • Traffic Adaptivity in Wireless Sensor Networks • Location Based Analyser
Torsten Braun: Service-Centric Networking A4 Mesh: Environmental Monitoring with Wireless Mesh Networks Thomas Staub, Benjamin Nyffenegger, DesislavaDimitrova, Torsten Braun: Operational Support of Wireless Mesh Networks Deployed for Extending Network Connectivity, 1st International Workshop on Opportunistic Sensing and Processing in Mobile Wireless Sensor and Cellular networks (MobiSense), Bilbao, May 9-11, 2011
Torsten Braun: Service-Centric Networking EU FP7 Wisebed (until 6/2011): WSN Testbed Management System
Torsten Braun: Service-Centric Networking TARWIS Experiment Configuration
Torsten Braun: Service-Centric Networking Recent WSN Experiments • Maximally Traffic-Adaptive and Energy-Efficient MAC Protocol [EWSN 2010] and Software-based Energy Usage Estimation [EWSN 2011] • Adaptive Forward Error Correction • TCP Support • Local data and acknowledgement retransmissions • Adaptive retransmission timeouts based on activity monitoring and path length detection • Duplicate suppression
Torsten Braun: Service-Centric Networking Motivation for Content-Centric Networking • Today’s network traffic is dominated by information retrieval rather than point-to-point communication between machines or humans. • Today: huge amount of data sent redundantly on a link • Circuit communication model is not considered as appropriate any more. • Future communication architecture should focus on information objects instead of nodes. • Today, wires and memories solve complimentary issues: • Wires move information in space. • Memories move information in time. • Future communications architecture should unify both issues. [modification of slides on CCN from NDN and CCNx projects]
Torsten Braun: Service-Centric Networking Traditional Web Retrieval / Web Services search engine / service registry web server/ web service DNS server user’s end system
Torsten Braun: Service-Centric Networking Related Work • Peer-to-Peer Networks • Construction of overlay networks • Content / service discovery, e.g., using distributed hash tables, flooding, random walks, etc. • Web Caching • Providing content for local users • Content Distribution Networks • Routing and redirection of HTTP requests • Cache management
Torsten Braun: Service-Centric Networking Content-Centric Networking (CCN) • [Jacobson et al., ACM CONEXT, December 2009] • Combination of content lookup and message routing • Idea: describe the users’ interests in the message header, but not where to get it. • Messages (using XML encoding) • Interest: content name, selector • Data: content name, signature (info), data • Hierarchical content names • Example: /unibe.ch/braun/lecture/20100405
Torsten Braun: Service-Centric Networking Related Projects • NDN = Named Data Networking, www.named-data.net • CCNx = Open Source Core Software Project for Content-Centric Networking, www.ccnx.org • Scalable and Adaptive Internet Solutions (SAIL), www.sail-project.eu
Torsten Braun: Service-Centric Networking IP Model FIB SRC DST FIB: Forwarding Information Base
Torsten Braun: Service-Centric Networking Processing of Interest Message in CCN • Longest prefix match on content name in Content Store (CS): returning data and discarding Interest • Pending Interest Table (PIT) match: adding request to PIT and discarding Interest • Forwarding Information Base (FIB) match: forwarding of Interest towards data • FIB population by announcements of content availability
Torsten Braun: Service-Centric Networking CCN Model: Match in Content Store CS FIB Name Data Name Data PIT Name CS: Content Store FIB: Forwarding Information Base PIT: Pending Interest Table
Torsten Braun: Service-Centric Networking CCN Model: Match in Forwarding Information Base CS FIB PIT Name CS: Content Store FIB: Forwarding Information Base PIT: Pending Interest Table
Torsten Braun: Service-Centric Networking CCN Model: Match in Pending Interest Table Name CS FIB PIT x CS: Content Store FIB: Forwarding Information Base PIT: Pending Interest Table
Torsten Braun: Service-Centric Networking Content Distribution • /unibe.ch/braun/lecture/20100405 1 2 3 4 5 6 7
Torsten Braun: Service-Centric Networking Naming • Any kind of names are possible → flexible naming • Naming approaches • 2 phases: mapping of ID to locator, routing to data source • 1 phase: direct ID-based routing to data source • Examples • /unibe.ch/braun/lecture/20100405 • /weather/greece/20110906 • CCNx support for simple operations • %C1.org.ccnx.frobnicate~1~37 • command in the namespace org.ccnx • operation is frobnicate, which takes 1 and 37 as arguments
Torsten Braun: Service-Centric Networking Routing • Longest Prefix Match Routing (as in IP) • But: different FIB entry semantics • IP: IP address prefix can be reached via an outgoing interface for an existing FIB entry • CCN: content name prefix mightbe reached via an outgoing interface for an existing FIB entry • FIB entries should be populated proactively for known content. • Alternatively, searching for content, e.g., using broadcasting
Torsten Braun: Service-Centric Networking Content-Centric Networking • Advantages • Automatic content distribution • < 1 round-trip-time • Minimization of latency • Minimization of bandwidth (cf. multicast) • Local congestion control • Built-in security • Drawbacks • Routing (and naming) as open issue • Lacking support of flexible services
Torsten Braun: Service-Centric Networking Service-Centric Networking (SCN) • CCN is content-centric and encodes a few operations on content as extensions of names. • Proposal: Service-Centric Networking • Extension of content-centric networking to support services, possibly operating on content. • Description of a service using content naming scheme, e.g., /google.com/file-service • Service request to invoke a service in Interest message • Service response in Data message • Services • Infrastructure services, e.g., cloud computing services • Client-oriented services, e.g., web services, remote procedure calls • Continuous content retrieval and streaming services, e.g., A/V conferencing, streaming • In-network processing, e.g., sensor data aggregation and fusion
Torsten Braun: Service-Centric Networking Advantages of SCN • Low delay and efficient network resource utilization due to • No need for separate service lookup and service registry • Caching of service data; extended caching of multimedia data (transcoding) or sensor data (data fusion) • Optimized service selection (considering load, delay metrics for service request routing) • Location-based services
Torsten Braun: Service-Centric Networking Uniform Naming for Services (Functions) and Content (Data) • Services perform (data) processing and are represented by functions to be invoked. Content stores for data. • Service-centric networking should support both data and functions. • Object-orientated programming paradigm integrates both functions and data into objects. Method calls among objects to invoke functions. • Proposal: Object names for both services (functions) and content (data), e.g., • /youtube.com/rendering • /unibe.ch/braun/lecture/20100405 • Advantages of object-oriented approach • Uniform naming • Services can be implemented as a set of cooperating objects
Torsten Braun: Service-Centric Networking SCN Object Types function1 read read function2 content data content data function1 function3 function2 1: Content Object 2: Service Object 3: Content/Service Object
Torsten Braun: Service-Centric Networking Example: Audio/Video Mixing client mix read write read write read write video 1 video 2 video 3
Torsten Braun: Service-Centric Networking Service-Centric Network SCN router Service request/response
Torsten Braun: Service-Centric Networking Continuous Data Flows • CCN Interest messages must be continuously submitted for continuous data flow, e.g., VoIP, streaming, sensor information • Option: deployment of states (cf. gradients in directed Diffusion) to support continuous forwarding
Torsten Braun: Service-Centric Networking Moblity and DTN Support CCN: Forwardingof Data isbased on PIT entries, nousage in mobile networks Encounter Possible message exchange at encounter Exchange of interests Exchange of relevant data Possibly two phases: own vs. others’ interests
Torsten Braun: Service-Centric Networking CCNx in Mobile Environments • Benefits: • Broadcast property of the wireless medium • Flexible communication routes not important • No beaconing required • Reduced average delay / less hops due to possible caching • Problems: challenging evaluation • Repeatability • Unpredictable wireless environments
Torsten Braun: Service-Centric Networking ExperimentationPlatform
Torsten Braun: Service-Centric Networking Conclusions and Outlook • Service-Centric Networking as a new paradigm extending content-centric networking using an object-oriented naming concept to be integrated into DTN environments • Open Issues • Implementation architectures • Service management and composition • Routing • Service parameter support • Mobile ad-hoc networks • Delay-tolerant networks • …
Torsten Braun: Service-Centric Networking Further Reading • Torsten Braun, Volker Hilt, Markus Hofmann, Ivica Rimac, Moritz Steiner, Matteo Varvello:Service-CentricNetworking,FourthInternational Workshop on the Network ofthe Future , Kyoto, Japan, June 9, 2011 • Thomas Staub, Reto Gantenbein, Torsten Braun: VirtualMesh: an emulationframeworkforwirelessmeshand ad hoc networks in OMNeT++, SIMULATION, Vol. 87, No. 1-2, p.66-81, January, 2011 • seervs.unibe.ch/research/publications
Torsten Braun: Service-Centric Networking Thanks for your attention ! • rvs.unibe.ch/research