中国资产评估协会研究课题管理办法 T

1、 Presentation given at the e-Science Institute, EdinburghSeptember 14, 2006Gregor v. Bochmann School of Information Technology and Engineering (SITE)University of OttawaCanada :/ site.uottawa.ca/bochmann/talks/FutureNetworkingChallenges for the Future of Networking AbstractThe technical foundations

2、for the Internet were developed more than 30 years ago. Since over 10 years, it has developed into a general communication infrastructure used by people and industry for a variety of applications. While e-mail and the Web were first the most important applications, newer developments have introduced

3、 wireless communication and new applications, including multimedia, e-commerce, etc. Certain applications, e.g. in the area of e-science, have extreme requirements in terms of bandwidth or delay that cannot be provided by the current Internet. - This talk will give a personal view of the challenges

4、that must be faced for the future of the Internet and the distributed applications using it, including managerial and technical aspects. Some of these issues are (1) the integration of wireless LANs and ad-hoc networks with the wired network, (2) fast optical switching, (3) user-empowered network ma

5、nagement, (4) security and trust management, (5) standards for distributed applications (e.g. Service Oriented Architecture) and (6) ubiquitous computing. The talk will provide a general discussion of these issues and present certain examples of innovative applications.OverviewThe current Internet a

6、nd applicationsResearch management - Grand ChallengesResearch issues in networkingOptical networks (the physical level)Issues for distributed applicationsConclusionsInternet: Some CharacteristicsPacket switchingBuffered in each router or switch (delay)IP : connection-lessLogically simple, but requir

7、ing address look-up for each packetConnection-oriented service allows for more efficient switching, e.g. new MPLS technologyThere are not enough addresses. Solutions:use of internal addresses and address translation (NAT); however, internal addresses are not reachableor better: use IPv6TCP : control

8、s flow between end-systemsProvides reliable information flowMany applications need a logical connection between processes running in different hostsNot suitable for interactive voice or video traffic (retransmission introduces delays)Not suitable for very large bandwidths (order of Gbps)UDP : non-re

9、liable alternative to TCPSome extreme applicationsLarge bandwidth and low delay : Video teleconference (e.g. round-trip delay of 0.1 sec at 10 000 km) Need for multicasting: video broadcasting (e.g. 10 Mbps to 10 000 users : 100 Gbps)Extreme large bandwidth: e.g. 10 Gbps for e-science applicationsEx

10、tremely low delays: tele-manipulation (e.g. eye surgery training); distributed music ensembleAd hoc networking (without fixed infrastructure)people in local meetingSensor networks (large number of sensors, low battery life, may fail)Existing communications infrastructuresTerrestrial transmission inf

11、rastructuresOptical fibresWavelength division multiplexing (each wavelength : typically 10 Gbps)For transmission, data is converted (from the electrical domain) into the optical domain (and back, by the receiver) 10 Gbps is too much for most applications, it must be sharedBandwidth sharing for telep

12、hony (end-to-end flows of fixed bandwidth, not packet switching)Sonet or SDH (time division multiplexing)ATM (cell switching)Packet switching may be used for this purpose (switching in the electrical domain)Packet switch could use 10 Gbps wavelength, or a fraction provided by SDHTime sharing through

13、 photonic switching, e.g. burst switchingCellular networks (designed for telephony)Fixed wireless networks (WIFI)Network management and scalabilityNeed for interworking between different domains (subnetworks belonging to different organizations)Limited visibilityService level agreements (static dyna

14、mic)Large number of (scalability)DomainsRouters / switchesHost computersCommunicating devices (terminals, phones, TVs, kitchen stoves, etc.)Security and reliabilityA faulty behavior of a single router should only have local impact; idem for failuresR&D - a long path: From new idea to market placeTyp

15、ical time : 20 yearsExample: Modeling distributed systems by state transition diagrams1969: Bartlett describes a communication protocol with finite state machines (FSM)1976: First version of SDL includes FSM notation1977: Bochmann and Gecsei propose Extended FSMs for modeling communication protocols

16、1980ies: Standardization of formal description techniques (FDTs) by ISO and ITU, including SDL; university-based tool development1987: Harel proposes State Charts (including certain extensions of above notations)1990ies: Commercial development of software tools supporting these notations1995 ?: Unif

17、ied Modeling Language (UML) defined by OMGAround 2005: Integration between SDL and UML Version 2 The research planning process (A)Funding of research and developmentBy industry (internal or external research)Objective: improve competitiveness Better productsBetter development and production methodsO

18、nly larger companies perform longer term research and planningBy government organizations (industrial and university research)Improve competitiveness of countryCompetent peopleImprove global competitiveness of local industryDevelopment of Intellectual Property (IP) to be used by local industryDiffic

19、ulty of prioritizing the different fields of science and technologyGive equal chances to all disciplines ?Declare certain fields as national priority ?Let industry buy-in for joint government-industry funding programsThe research planning process (B)Community-based research planningConsensus buildin

20、g: through mailing lists, discussions at workshops / conferences, research collaborationsExamples:The UK Grand Challenges: a perspective on long-term basic and applied researchNSF (USA) Workshop on Overcoming Barriers to Disruptive Innovation in NetworksResearch program of E-NEXT (a EU - FP6 Network

21、 of Excellence) “CoNEXT conference in Toulouse, Oct. 2005 Canadian research network on Agile All-Photonic Networks (AAPN, funded by NSERC and 6 industrial partners) Grand Challenges (defined in the UK)See “Definition of a Grand ChallengeA grand challenge should be defined as to have international sc

22、ope, so that contributions by a single nation to its achievement will raise our international profile. The ambition of a grand challenge can be far greater than what can be achieved by a single research team in the span of a single research grant. The grand challenge should be directed towards a rev

23、olutionary advance, rather than the evolutionary improvement of legacy products that is appropriate for industrial funding and support. The topic for a grand challenge should emerge from a consensus of the general scientific community, to serve as a focus for curiosity-driven research or engineering

24、 ambition, and to support activities in which they personally wish to engage, independent of funding policy or political considerations. “ (Note: the quotes, here and in subsequent slides, indicate that the text is copied from the source documentation)The following two slides are from Robin Milners

25、talk “A scientific horizon for computing at the World Congres 2004 of the International Federation for Information Processing (IFIP), held in Toulouse.Grand Challenge ExerciseUK Grand Challenge ProposalsNote: No GC is dedicated to networking issuesUbiquitous Computing Grand Challenge Combination of

26、GC 2 and GC 4See Objective: “We propose to develop scientific theory and the design principles of Global Ubiquitous Computing together, in a tight experimental loop. “Engineering challenges:design devices to work from solar power, are aware of their location and what other devices are nearby, and fo

27、rm cheap, efficient, secure, complex, changing groupings and interconnections with other devices; engineer systems that are self-configuring and manage their own exceptions; devise methods to filter and aggregate information so as to cope with large volumes of data, and to certify its provenience. b

28、usiness model for ubiquitous computing, and other human-level interactions. “Ubiquitous Computing Grand Challenge (ii)“Scientific challenges:discover mathematical models for space and mobility, and develop their theories; devise mathematical tools for the analysis of dynamic networks; develop model

29、checking, as well as techniques to analyse stochastic aspects of systems, as these are pervasive in ubiquitous computing; devise models of trust and its dynamics; design programming languages for ubiquitous computing. “A comment: It is not clear where in the context of ubiquitous computing Networkin

30、g stops and Computing starts. In fact, networking involves much distributed systems management (including databases); and for the Internet applications, the application layer protocols are just as important as (if not more than) the underlying networking protocols.Note: Milner has developed a new de

31、scription formalism “Bigraphs for Mobile Processes “( see )Research topics in “NetworkingIssuesNetwork layer: new wireless technologies: cellular, LAN, PAN, ad-hoc, sensor, etc.Integration with wire-line InternetHigher bandwidthInter-layer control and management according to application needsPhysica

32、l layer: technology pushFaster electronic components, e.g. 10 Gbps EthernetFast optical switchingTrend: IP over Dense Wavelength Division Multiplexing (DWDM); elimination of intermediate layers of ATM, SONET; however, it may be IP over MPLS over DWDM.Application layermany new applications: importanc

33、e of multimedia application will increaseNew protocols for organizing applications: Web Services, Grid, peer-to-peerNew ways for identifying and searching services, including concern for security and trustNetworkserviceArchitectural levels of Networking Technology a narrow-waisted hourglass model:Ov

34、ercoming Barriers to Disruptive Innovation in NetworksWorkshop organized by NSF (USA) “Overcoming Barriers to Disruptive Innovation in Networking (Jan. 2005)see Starting point: “ The Internet is ossified: Adopting a new architecture not only requires modifications to routers and host software, but g

35、iven the multi-provider nature of the Internet, also requires that ISPs jointly agree on that architecture. The need for consensus is doubly damning; not only is agreement among the many providers hard to reach, it also removes any competitive advantage from architectural innovation. This discouragi

36、ng combination of difficulty reaching consensus, lack of incentives for deployment, and substantial costs of upgrading the infrastructure leaves little hope for fundamental architectural change. “NSF workshop (ii)Requirements for the new Internet:“ Minimize trust assumptions: the Internet originally

37、 viewed network traffic as fundamentally friendly, but should view it as adversarial;Enable user choice: the Internet was originally developed independent of any commercial considerations, but today the network architecture must take competition and economic incentives into account;Allow for edge di

38、versity: the Internet originally assumed host computers were connected to the edges of the network, but host-centric assumptions are not appropriate in a world with an increasing number of sensors and mobile devices;Design for network transparency: the Internet originally did not expose information

39、about its internal configuration, but there is value to both users and network administrators in making the network more transparent; andMeet application requirements: the Internet originally provided only a best-effort packet delivery service, but there is value in enhancing (adding functionality t

40、o) the network to meet application requirements. “Identified 7 areas of research (see next slides)7 research areas:SecurityEconomic incentivesAddress bindingEnd-host assumptionsUser-level route choiceControl and managementMeeting application requirements (see next slides)SecurityProblem indications“

41、traffic must be viewed as adversarial rather than cooperative“To take one example, a single mistyped command at a router at one ISP recently caused widespread, cascading disruption of Internet connectivity across many of its neighbors.Benefits of better security“ improve network robustness through p

42、rotocols that work despite misbehaving participants,enable security problems to be addressed quickly once identified, isolate ISPs, organizations, and users from inadvertent errors or attacks; prevent epidemic-style attacks such as worms, viruses, and distributed denial of service; enable or simplif

43、y deployment of new high-value applications and critical services that rely on Internet communication such as power grid control, on-line trading networks, or an Internet emergency communication channel; andreduce lost productivity currently aimed at coping with security problems via patching holes,

44、 recovering from attacks, or identifying attackers. “Security (ii)Interesting architectural approaches:“prevent denial of service by allowing a receiver to control who can send packets to it “making firewalls a fully recognized component of the architecture instead of an add-on that is either turned

45、 off or gets in the way of deploying new applications. A clean specification for security that makes clear the balance of responsibility for routers, for operating systems and for applications can move us from the hodge-podge of security building blocks we have today to a real security architecture

46、“A careful design of mechanisms for identity can balance, in an intentional way rather than by accident, the goals of privacy and accountability. Ideally, the design will permit us to apply real world consequences (e.g. legal or financial) for misbehavior. “Economic incentivesProposition:“A future d

47、esign for an Internet should take into account that a network architecture induces an industry structure, and the economic structure of that industry. The architecture can use user choice (to impose the discipline of competition on the players), indications of value flow (to make explicit the right

48、direction of payment flow), and careful attention to what information is revealed and what is kept hidden (to shape the nature of transactions across a competitive boundary). “Address bindingProblem with IP addressesThere are not enough solution: IPv6They serve as machine identity (instead of only i

49、dentifying the network attachment point, the location)this leads to difficulties for mobile devices (e.g. Mobile IP routing is not straightforward IP address changing dynamically)IP address (as machine identifier) also used for securityProposed solution approachesHost Identity ProtocolIt provides se

50、cure host identificationRouting is based on IP addresses that are treated only as ephemeral locators“ end-points (as equated with physical machines or operating systems) need not have any globally known identity at all. Instead, application level entities have shared identities , and higher level na

51、me spaces such as a redesigned DNS are used to give global names to services, so that they can be found. “End host assumptionsIssues with sensor networkssensors may be intermittently connected routing may be based on data valuesSolution approaches: Overlay networksOverlay for realizing special routi

52、ng functions, e.g. diffusion routingOverlay for delay-tolerant routing (e.g. for e-mail; also allowing “access in a variety of impoverished and poorly connected regions “)User-level route choiceObjectives: increase the users choice and introduce more competition“ Instead of applying a one-size-fits-

53、all policy to their traffic, ISPs could perform routing and traffic engineering based upon the user traffic preferences offer unique policies such as keeping all traffic within the continental United States for security reasons. “ This selection creates a more complex economic environment; it offers

54、 potential rewards in user choice and competition, but requires solutions to issues of accounting, pricing, billing, and inter-ISP contracts. “Control and managementStatement: Management of the Internet is very complex (for all parties involved)Solutions: not clear (there are references to ongoing w

55、ork)One problem: limited visibility of internal parameters from outside the network (opaqueness)A network should “support communication of operationally relevant information to each other. Such information could be aggregated and analyzed, thereby facilitating load balancing, fault diagnosis, anomal

56、y detection, application optimization, and other traffic engineering and network management functions.One needs a compromise between information hiding and visibility for management. Meeting application requirementsProtocol layer architecture is a narrow-waisted hourglass modelAdditional requirement

57、s:“QoS control, multicast, anycast, policy-based routing, data caching Possible solutions:Add more functions to IP layerUse overlay networks to provide additional functionsIP NetworkserviceSome personal commentsOverlay networksPrinciple: A certain number of servers connected to the Internet play the

58、 role of virtual routers in the overlay network. Note: This is the way MBone implements multicasting over the current IP Internet service.The NSF workshop stresses the use of overlay networks for experimentation with new approachesCould such architectures present the final solution ? NO, overlay tec

59、hnology, such as peer-to-peer computing, may be useful for certain applications, but cannot be a solution for building a networkExisting well-known applications Napster and BitTorrent media distribution, and other peer-to-peer applicationsMulticasting of multimedia presentations, possibly including

60、different quality variants A Testbed: US-based Planetlab ://; see also :/ Some personal comments (2)Lightpaths - “Underlay Networks“ ?Experimental research networks provide high-bandwidth “lightpaths“ between different sites for e-science and other applications that require guaranteed