Growing of Internet a permanent challenge for designers and network engineering Ji ř í Navrátil jiri@cesnet.cz European Future Networking Initiatives Workshop 22.2.2007 Amsterdam
Introduction to EFNI w orkshop • Internet expansion and consequences • Next generation of Internet (directions and supporting projects, FIND, GENI) • New terminology: Slicing, Virtualizaton, PlanetLab, VINI, etc. • New networking phenomena, concepts, approaches (DHT, P2P, CAN, ROS)
Partial visibility of the Internet from one router BGP table analysis (from the routing tables) Source: http://www.caida.org/tools/measurement/skitter/
What are the problems of Internet ? Speed and capacity ? In network backbones ? In aggregation networks? last mile ? wireless (ad hoc networks, Wimax) ? Access to the network ? from individual machines (PC,MAC,Linux), Supercomputers, PDA, phones, edge points Distribution of services in requested quality to end users to universities, offices (thousands of sites in each country) to homes (millions of access points) mobile users Utilization of existing networks (Measurement and monitoring) How do we know what users are doing and what they want, what are the loads od individual segments of Internet ? Security aspects ? Yes, definitely, all of these areas has own difficulties and clear road map for future developments However, they don’t threaten the system as whole
The real problems of IP world are in the principles • IP addresses ? Yes, before 1994 nearly collapsed. Problem postponed because of reusable private IP, NAT. It is reason why IPv6 is not so hot • Naming ? Yes, DNS still dominate and it has more and more problems the other systems start to use own naming strategy based on GUID • Routing ? Yes, since 1989 BGP (protocol based purely on agreement of ISPs - routing policy). All other known protocols are unacceptable, technically problematic and they are used just locally, many existing routes is not used, quality of routes is not under control BGP 4 ? Yes, Introducing AS was step to aggregation for routing purposes, it helps to postpone problem with effectiveness of routing. AND the # of ISP and # of AS grow exponentially !
How Internet Grows In history The grow of Internet Routing Tables 80000 Expectations 70000 routes 70000 60000 50000 40000 #routes 30000 20000 350 10000 0 1988 92 94 95 96 97 98 99 2000 CIDR, PRIVATE IP, NAT bring slowdown of growing RT (in 2000 - 980 millions of users ???)
How AS grow ing brings problem to BGP Grow in 94– 06 Source http://www.routeviews.org/dynamics Remark. Individual lines are prefixes (paths) from different peers This is a reason why your engineers needs more and more powerfull systems Flapping = routes on- off-on-off … http://sahara.cs.berkeley.edu/jan2004-retreat/slides/mcc_rootcause_sahara.ppt
More about the weaknesses of the Internet - performance bottlenecks at peering points – Ignores many existing alternate paths – Prevents sophisticated algorithms – Route selection uses fixed, simple metrics – Routing isn’t sensitive to path quality (See next examples) The Internet is ill suited to mission-critical applicatio Paxson (95-97) 3.3% of all routes has serious problems Labovitz (97-00) 10% of routes available <95% of time 65% of routes available <99.9 3 minutes minimum detection time for failure average recovery ~ 15 minutes Chandra (01) 5% of faults last more than 2 hours 45 minutes Wang (06) 80 % of problems on the path is caused by routing
RON - Resilient overlay networks David Andersen, Hari Balakrishnan, Frans Kaashoek, and Robert Morris MIT Laboratory for Computer Science http://nms.lcs.mit.edu/ron/ • Measure all links between nodes • Compute path properties • Determine best route • Forward traffic over that path Experimental testbed running for users, Main problems - not suitable for disruptive operation, - low statistics of problematic cases (waiting for errors)
Menu Traceroute analysis Via Abilene Via CALREN/CENIC Example of routing changes (path SLAC – CALTECH) ABwE Overview
PROBLEM IS NOT ONLY TO HAVE NAME (registration) But how TO HANDLE resolution (conversion from/to IP) and UPDATE databases which are bigger and bigger com TLD TLD ns ns ns Recursing requests .hp. . ibm. .nl ns ns .cz .de ns ns ns ns .cvut. ns ns ns ns ns ns ns ns ns .fel. ns ns ns ns ns ns .fjfi. ns ns ns .fs.cvut.cz Most request is resolved on the lowest level but not all data are available => Recursing requests browsers Remember: Each nice Web page can contain several resolutions !! (reference to icon/picture/doc located somewhere in Internet) and for seeing it must be resolved !!
All these systems were designed for traffic loads that reflect the rate and complexity of human activities How DNS will react on machine-machine applications (crowlers, traffic reviewer,..) How is robust, scalable, sensitive to the attacks and misconfigurations What is the rate of DNS updates and big volume of data it represents ? 1-2 M updates/hour on root DNS 20 top ASes make 50 % updates (China, US, Spain) 97% updates is from WINDOWS machines Wrong coordination between DHCP and DNS for private IP can creates unwanted traffic and requests to global DNS. This leakage is inappropriate from the traffic and also from the security aspects. REFERENCE CAIDA papers: A.Broido, E.Nemeth, kc claffy, SPECTROSCOPY of Private DNS update Sources A.Broido, H.Shang, M.Fomenkov, Y.Hyun, kc claffy, The Windows of Private DNS Updates
NSF FIND “Future Internet Design” in 2005 as reaction to existing problems • Creating the Internet you want in 10,15 Years • The Internet which society TRUST • Support pervasive computing (from PDA to Supercomputing) • Connecting devices and users with all types communication channels from wireless to optical light paths • Enable accept further developments and innovations
from Darleen Fisher and Guru Parulkar NSF-CISE presentation
from Darleen Fisher and Guru Parulkar NSF-CISE presentation
from Darleen Fisher and Guru Parulkar NSF-CISE presentation
Situation is getting worse From: David Alderson CALTECH , NSF Find meeting, Dec. 2005
Larry Peterson Princeton University: A Strategy for Continually Reinventing Internet Why now ? (May 2005) many architectional proposals ( look on the statistics RFC, papers, etc.) research community is ready to making it real Enabling technology Infrastructure exists (NLR, Planetlab, .. GN2,.. } HOW ? Two paths for changes Incremental Clean-Slate (replace Internet with new architecture) many problems on first path (many limits, hard manage,, vulnerability, hostile) there are Barriers to second path: Internet ossificated, cannot be replaced Inadequate validation of potential solutions tesbed dilemma : production testbed = incremental change experimental testbed = no real users !
Focus of FIND On Reinvented Internet Architecture and not on individual network technologies Internet evolution influenced by clean-slate approach Alternate architecture(s) coexist with the current Internet Virtualization becomes the norm with plurality of architectures New services and applications enabled
Defined Stages of Research for 2007 and Later Architectures as they emerge will be made operational and tested • Simulation • Emulation • Run on a large-scale GENI facility Experiments with new architectures at global scale
http://nile.wpi.edu/NS/
Peter A.Freeman NSFVICE Jan 2006 ? ? 2009 2007 Filling GAP ( validate new arch. Under realistic conditions Keep potential deployment in sight ) Work on existing experimental. infrastructure Emulab front-end to PlanetLab Experiments spanning some combination of… Emulab + ORBIT + WAIL + PlanetLab ViNI: Virtualized Network Infrastructure PlanetLabslices on layer 2 networks (NLR + Abilene) Internet-in-a-Slice (Click + XORP)
Larry Peterson Princeton University: A Strategy for Continually Reinventing Internet (May 2005) Each architecture (service) runs in own slice Planetlab node as INGRESS NLR as high-speed backbone
In “A Strategy for Continually Reinventing Internet” (May 2005, Larry Peterson)
Distribution of load and functionality in Hardware Source: From GENI backbone working group
Why virtual architectures ? The programs that should control many different entities in real time with complex timing often multiplicatively same for different segments of the huge systems are rather complex. You can separate the tasks into independent HW (computers) each responsible for part of the whole system). The reason is not only the distribution of the load but also distribution of complexity . The computers are more and more powerful so they are ready to work in “pseudo parallel mode” and to accept some overhead. Application software is much simple. The next step is to create more independent systems (virtual machine VM) on one physical computer. Each VM can run one or more programs. The complexity for writing and running application is much lower than in original design
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