Dm Netedu Presentation Feb07

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DM, February 2007, p.1NeTReL, N et w ork i ng & Tel ecommuni cati ons Research

Networking Research:Trends and Issues

Deep MedhiNetworking & Telecommunication Research Lab (NeTReL)

Computer Science & Electrical Engineering DepartmentSchool of Computing & Engineering

University of Missouri-Kansas City, USAhttp://www.csee.umkc.edu/~dmedhi

[email protected]

D. Medhi, 2007. Permission is granted for this material to be shared for non-commercial, educational purposes.To disseminate otherwise or to republish requires written permission from the author.


Outline

Review: CSTB 2001 ReportBroad Categories for NetworkingResearch

TrendsSome Historical ExamplesIssues


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CSTB2001 ReportLooking Over the Fence at Networks: ANeighbor's View of Networking Research By Computer Science & Telecommunications

Board (CSTB), National Research Council ofUS

Published in 2001 by National Academy Press,availablehttp://books.nap.edu/html/looking_over_the_fence/report.pdf

Addresses Three Broad Areas


CSTB 2001 report: First Area

Measuring: Understanding the InternetArtifact Challenge of Scale

How to infer based on incomplete knowledge ofconfiguration

How to soundly sample network traffic, and validity ofsampling approach

Measurement Infrastructure Deployment and operational challenges

Nontechnical factors Compose of production commercial systems

E.g., Confidentiality and privacy of data


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Trouble with Success (CSTB 2001Report)

ossification := The process of becoming set in arigidly conventional pattern, as of behavior, habits,or beliefs (American Heritage Dictionary)Intellectual ossification E.g., its not TCP!

Infrastructure ossification What researchers want may not be deployed in a

commercial network (e.g., limited multicast deployment,

QoS)System ossification Research results judged based on how hard it is to deploy on

the Internet


CSTB2001 ReportTo Summarize Very well done Over five years old Current Internet view/improvement

Whats Missing? Wireless networking

Optical networking Delivery/Access networks (e.g., Cable/DSL Networks) Interaction of different networks Network security


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Network Research:

Two Broad Categories: Current networks & related research To imagine future networks/services &

related research

Influence of External/Overnight

Factors


Current Networks-Related Research

How to measure/model behaviorDriven by limitationsHow to improve

Due to scalability issues, operationalproblems Traffic engineering Network reconfigurability Security


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Research Trends: Current Networks-related: A Few Examples

Scalability (in every way thinkable! routingtable lookup, network models, )Internet measurement, sampling Backbone Networks Access Networks

Protocol extensibilityRouting: BGP, inter-network trafficengineeringIntegration of traditional IP networks andPSTN/multimedia services


uture Networking or Services:Research, Technology Concepts &Development

Some Recent Examples: (~last 20 years)Networks: ATM, MPLS, Optical networking

Cellular Networks, 3GPP, WiMAXServices: WWW, P2P, IM, text messaging

Associated protocol development, modeling,routing, security, May or may not be commercially successful


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esearch Trend: utureNetworks/Services and related

researchNetworks/Services: MPLS/GMPLS Virtual Private Networking Sensor Networks Software Radio Service Concept Development

IP Multimedia SubSystem (IMS) Secure Group Communication

Faces issues such as MAC protocol, performance modeling,security as built- in feature, protocol development,performance etc


External/Overnight Factor

Something an architecture wasntoriginally intended for, but is forced tohandle


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TCP Collapse

TCP throughput drop (1986)

Led to new congestion control/timeradjustment approach Key here is on understanding the dynamics

Sliding-window, window-adjustment, timer-

adjustment, sampling,


Denial of Service (DoS) Attacks

Network functionality allowed the possibilityfor DoS attack First wave: Web-server oriented Next wave: network impact (e.g. code-red virus)

Follow-up Research TCP accept queue, OS implementation etc Source-oriented (stop close to the source) Router-level research: IPprefix lookup


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IP Network Traffic Engineeringissues for large providers

OSPF/IS-IS: dynamic routing protocolProblem: determine link weights in OSPF/IS-IS networks to load balance a networkEarly-exit/Late-exit routing issues

Router Buffer sizing: Bandwidth-delay product

Consider 40 Gbps link and 250 ms round-trip delay


Routing Table Growth

CIDRIP address lookup algorithms Need to stay with line rate (approaching

40Gbps)Packet Filtering and classification


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Router Architecture evolution

General purpose computer architectureDifferent architectures for differentpurposes Shared CPU architectures Shared forwarding engine architectures Shared nothing architectures

Clustered architectures


Router Architectures


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Needs/Issues in NetworkingResearch

Recap: Current networks-related research Future networks/services-related research External factor that drives research (often

for current networks; however, principlesmight be useful for future networks)

Issues: To highlight a few examples


Broadband Access Technology andService Dynamics

Broadband access Technology (DSL,Cable Modem) designed for webmodel Lot of download bandwidth Not much upstream bandwidth

Challenge faced (last few years) P2P services: Napster, VoIP services


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Broadband Access Technology andService Dynamics (contd)

Can we design an access mechanism that isdynamically adjustable between upstream anddownstream Time-Division Duplexing (TDD)? Others? Require solid knowledge of physical, data link, and

transport layer?Questions: How well will the dynamics work? How does it impact service behavior? Where is the trade-

off? Are there possible pitfalls due to dynamism? And How to

handle them? (recall: lesson learned from Telephone dynamic routing, TCP

congestion, )


Core Network Interactions: Multi-Layer Networking Dynamics

If IP layer link setting is dynamicallyadjustable to address for failureIf optical networking handles its owndynamic routing (GMPLS) Good for each network, may not be good

together? Can the inter-related network go into tailspin?

How does DoS attack based increase in networktraffic impact dynamic adjustability?

How do we know good from bad traffic (e.g., anew P2P product popularity, or a new DoSattack)?


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Routing table growth

Data source: http://bgp.potaroo.net/

Our recent estimate:N = 105625 + 920.608 (4 Y - 8007)1.52894 , for Y >=2002


Routing table growth: problemsInternet Architecture Board: Routing andaddressing workshop (reported at IETF67,San Diego, CA, Nov06) TCAM/SRAM for routers slow growth ASIC is already pushing limits

Memory speed improves about 10% per year State growth is super-linear Current trends in the growth are not scalable Use of IP addresses for both ID and Location is a

problem Sort of second CIDR wave, but more difficult


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Future Directions:

Developing disruptive prototypesthat challenge the current InternetHow to do it?Not possible to test over the currentInternet Its a production network!

Retro-fitting is difficult (remainspatch-work problem)


Steps to Making it happen ..NSFs new research program: FIND (Future Internet Design) Inviting proposals on radical architectural directions

GENI (Global Environment for NetworkingInnovations) http://www.geni.net A large-scale proposed test-bed for experimentation

Experimentation in every layer of the network Customized hardware development Test before deploy time environment Allow many researchers to participate Alliance with European Community


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How to ensure that all problemsare addressed

Classify problems: Wired/wireless,Core/AccessCore Networks

Some idea because of IETF, NANOG (e.g. BGP problem,addressing growth )

Access Networks Cable/Modem, wireless Campus/Enterprise Networks

Need input from Net@Edu community

Security/Resilience as inherent designparadigm


Finally, at a Fundamental Level

Is there a new network communicationmode out there?Consider time spacing:

+ Between Telegraphy and Telephony: ~50years

+ Between Telephony and Internet: ~100 years+ Between Internet and ??

- Will everything now onward be incremental?- How to not get trapped in ossification?

Dm Netedu Presentation Feb07

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