Dodge, C.

Möring, H.

Pfeiffenberger, Hans

Schulz, B.

English

Chris Dodge

Heinz Möring

Hans Pfeiffenberger

Arne Schulz

Crossref

A Distributed Administration System for Ocean Simulation Data

Electronic Publication Information Center

Observations of an IT User in Charge of an ATM-MANHans PfeiffenbergerAlfred Wegener Institute for Polar and Marine Research1Bremerhaven, Germanyeginning 1995, a regional ATM network extending over a 65 km diameter andmore than 150 km fiber optic cable was built and operated by a group from thescientific community of the state of Bremen. Also, one complete LAN serving 500users and some parts of LANs were rebuilt using ATM LAN-E as the base technology.This platform also supplied specific projects with ATM connectivity to locations inEurope and even Canada.This project, called ãLandesbreitbandnetz BremenÒ catapulted the regionalscience and educational community as well as some small and big private enterprisesfrom the era of some 64 or 128 kBit/s Internet access points, used in 1994 ( plus oneplace of point-to-point broadband application piloting, at the AWI ) to a generalbroadband experience in 1996. It was made possible by the financial means of thesenators for economy and harbours and the staff of scientific institutions. It is devotedto research and development - mainly at the application level - and to generalqualification, and understood as a tool to speed up the economical restructuring ofthe region, facing the ãinformation ageÒ.Some technical as well as organizational peculiarities cannot be understoodwithout the knowledge of telecommunication law (near monopoly) and public andprivate funding of research (sparse) in Germany during this time. It was a mainundertaking to overcome  the legal and financial barriers - however, it succeededwithin a year. Then, the core network (as well as the AWI campus LAN) was designedto become operational within 6 to 9 month, to provide broadband IP connectivity  toavailable user equipment and LANs, while opening the possibility for innovativeprojects.Consequently, ATM was chosen as the base technology to connect two routersat the main sites (and more , later) via PVCs carrying classical IP. Some sites wereconnected via ATM LAN-E only, from the start, to economize on routers. The campusnetwork of AWI, which was rebuilt from scratch during the same period, was basednearly exclusively on an ATM backbone and LAN-E. Therefore, ATM signalling wasused extensively from the beginning, as opposed to other pilot networks at that time.This somewhat risky concept - considering time and experience constraints - couldonly be realized by a design involving components from a single manufacturer. Ciscowas chosen because early establishment of IP connectivity between existing campusLANs with staff experienced in Cisco products was a main milestone.oday, the 155 MBit/s network connects about 30 "participants" - ranging from asingle workstation with an ATM-NIC in a small firm to complete IP networksincluding a university campus. External connectivity is by access to the (IP-) sciencenetwork "B-WiN" and the ATM network of Deutsche Telekom at 34 MBit/s each. Thus,the network serves as a backbone for utility Internet access for most of the regionalscience and educational institutions as well as a platform for specific R&D projectssuch as the G7 project SPOCK2 which deals with distributed engineering in theaerospace industry, and the ACTS project EIES3 which is to set up a trialcommunications service between European harbours.Projects had access to European and transatlantic ATM pilot networks thanks tothe JAMES project of the European Commission and the generous help ofDeTeBerkom4 and Rechenzentrum of University of Stuttgart5. As soon as February1996 it was possible to establish Megabit ATM PVCs to Stuttgart and CRC, Ottawa,Canada in order to demonstrate distributed engineering, involving visualization andvideo conferencing components. Meanwhile, regular sessions have been held withItalian, Dutch, Belgian, Spanish and French participants. However, all but one of theBTapplications used IP (over ATM) only. (The exeption is an experimental HTTP overATM service)Considerable effort had to be spent each time when a connection wasestablished for the first time, adapting the configuration of user equipment or evenborder network switches at each end to the peculiarities of the other partner orintermediate networks.Even today it is not possible to set up a connection by signalling - which is nosurprise, considering that there is no agreed upon numbering plan as yet. However,once established, a guaranteed bandwidth for the end-to-end connections wasprovided as a minimum advantage over Internet connections.ome observations - as of autumn 1997 - are:• Building an ATM LAN-E based local area network with routers, ATM- andEthernet-switches from a single vendor is - almost - a plug-and-play operationtoday, given some experience in IP-network operation.This was experienced at least on two occasions, when upgrading the MANbackbone ATM switches in autumn of 1996 and exchanging the completebackbone equipment of AWI in autumn of 1997 whithin three hours each (afterpreparation and experiments in the lab, costing some person-days).• Under these constraints and given a little experience in ATM, LAN-E even provesuseful in extending an emulated LAN to another city, on the fly.Plugging an ethernet-switch into an ATM-switch in Bremerhaven, setting theATM-address of the LAN-E configuration server at the other institution in Bremenand assigning ethernet ports to VLANs took less than 15 minutes.• It is somewhat harder to integrate workstations and ATM-NICs of different flavoursinto these emulated LANs as clients.This is simply due to the fact, that each vendor of Unix and ATM-NICs has adifferent way of installing and configuring network interfaces, assingning them toemulated LANs etc. In a project using heterogeneous equipment, distributed overthe MAN in different institutions, with minor help from the MAN networkmanagment it was too much overhead for the ãusersÒ to keep a LAN-Econfiguration stable over numerous OS and driver upgrades, during 1996.• Integration of ATM equipment of a different vendor into the network remains to bea major undertaking.Two vendors agreed to set up showcases, involving video conferencing (withLAN-E based control connections) and MPOA, respectively, where two halves ofeach setup had to be connected over the MAN backbone as a carrier, fromBremerhaven to Bremen. Both were confident to install their demo in a day or two(as shown at the Networld and Interop), but failed. In a real world environment -as compared to the lab - and with real world support staff it may take person-weeks to connect complete ATM networks fully functional (1997)• The majority of user equipment is not ready to consume multi-Megabit streamsSince multimedia PCs have just arrived, much of the equipment on older LANscannot transfer f.e. video data from the network- to the graphics-adapter at thoserates. Many PCs even have difficulties to do simple filetransfers at more than 10MBit/s whithout tweaking drivers - which would cost support at many places.Therefore, in this MAN the bottleneck has moved from the network to the PC, forthe first time.• No native ATM "killer"-application has emerged on desktops.The case for ATM to the desktop would be - for example - a video stream, ananimation and a file transfer competing for an IP over 100BaseT attachment of aworkstation to a switch, as experienced at a virtual (bersee-)museum demo.Maybe this is a hen-and-egg problem at this time. After all: who else has ATM, atthe desktop or the server? Maybe it is wait (for RSVP) and see. However, thequestion will be similar: who has (will have) RSVP, end-to-end?Sontrary to the beliefs of some in 1995, LAN-E seems to be simple enough to bestable, useful and performing in real world user- and operational environments.Maybe6 LAN-E and its successors are the killer apps of ATM - if interoperabilityproblems are solved.This statement is derived from the truism that switching techniques, especially forthe majority of ethernet-ready user equipment, are a winner. In contrast to a pure IP-switching environment, LAN-E opens the opportunity to serve some legacy (i.e.: non-IP) systems in the short term and provides an additional layer of administration andcontrol (of security as well as cost) which may be welcome increasingly.In my opinion the main keys for success in the contest of broadband networktechnologies are ease of use and quality of service - from the user perspectitive  - andãcost of ownershipÒ, security and accountability - from the management perspective.It remains to be seen, if a RSVP, IP-switching and/or big router router strategycan satisfy those key requirements easier, earlier or less costly (on a broad scale,end-to-end) than one based on ATM-switching and MPOA. The problemsimplementing the former could be as demanding or as simple, but numerous (at theend-points) as those with ATM LAN-E described in the observations on theLandesbreitbandnetz Bremen.urrently, some project are in the design or implementation phase, which dealf.e. with an extranet for the harbours authorities and some firms involved inservices for maritme logistics, with an emphasis on security; broadband satelliteservices and broadcast, conferencing and surveillance quality video which all requiresome special kind of quality of service. It seems, that it is easier - with currentlyevailable equipment and services - to implement these using ATM.On the other hand, there are projects which f.e. need a close coupling between(compute-) servers, point-to-point. It seems to be easier to implement these usingGigabit-Ethernet. In a MAN environment this would require a transparent opticalchannel, end-to-end, to avoid uncertainties especially about latency. So in thisapplication it is not Gigabit-Ethernet which challenges ATM but a future all-opticalnetwork.                                                1 http://www.awi-bremerhaven.de/EDV/Projects/AWI-LBN and references therein2 http://www.spock.hs-bremen.de3 http://www.isl.org/projects/eies4 http://www.deteberkom.de5 http://www.uni-stuttgart.de/Rus6 Vorhersagen sind schwierig, vor allem, wenn sie die Zukunft betreffen (Niels Bohr)   (Predictions are difficult, especially, if they relate to the future)CCBremisches LandesbreitbandnetzUniversity-Campus Bremen and Technology ParcBRIG AWIHandelshafenBIBAISLZfNAWIColumbusstraße OC3 (SM)10BaseFL100BaseTArea BremerhavenArea BremenATM-Switch LAN-Switch RouterLegende Ethernet-LAN  WorkstationRepeater/Transceiver SM / MM - Converter10 Mbps Tranceiver © AWI Bremerhaven 1997MEVISHochschuleBussestr.HBA Bussestr.FDDIHochschuleKarlsburgHochschuleColumbusstr.InformatikBITZZARMDBH, PDVHochschuleBremenNeustadtswallHochschule BremenWerderstr.StadtbibliothekAirport Commercial Area /DASA AirbusBremen HarbourSt.-JürgenHospitalSuUBIDBSKPCongress CenterÜbersee-MuseumOC3 (MM)10BaseFLOC3 (SM)BreitbandWissenschaftsnetzDFN-VereinE3FDDIOC3 (MM)OC3 (SM)OC3 (SM)Stresemannstr.City Center10BaseFL (SM)10BaseFL (SM)OC3 (SM)OC3 (SM)ATM-PilotDeutscheTelekom AG      E3OC3 (MM)OC3 (MM)11 / 97VHSOC3 (SM)AWIColumbuscenter European Information Exchange Service for the Communication between Harbour Areas http://www.isl.org/projects/eieshttp://www.spock.hs-bremen.deIn the project SPOCK it is anticipated to  integrate the disciplines of aerodynamic aircraft design: Computational Fluid  Dynamics (CFD), Wind Tunnel experiment and Flight Test. This integration is based on the Computer-Supported-Cooperative-Work (CSCW) technology and aims the computerbased collaboration of geographically distributed teams via international ATM high speed networks and cooperation/ communication software. LegendRouter Ethernet-LAN(Thin-Wire) Hub(Twisted Pair) Repeater FDDI - RingLAN (E) -SwitchATM -Switch1SnapshotABuildingFiber(Mono-Mode)Fiber(Multi-Mode) Ethernet-cable(Thin-Wire)A B C D2A B C D4A B C D3A B C D1Restructuring the AWI Campus LAN4 Buildings (A - D)  -   500 Users  -  4 Snapshots (1 - 4)Snapshot 1 : Jan, 1996 Router, repeater, coax-based network ( with FDDI-ring for Crays, etc.) New structured cabling 50% completeSnapshot 2 : Feb 01, 1996 replace old Routers by switching equipment plus new router „on the stick“ (half a day) Snapshot 3 : Feb - Sep 1996 install hubs, migrate user equipment from coax, local talk to 10BaseT ethernet, map old physical subnets to VLANs, cabling 100% complete (Jun). Replace „old“ ATM-switch by new model, give an ethernet-switch to high end users (Sep)Invisible : Begin restructuring VLANs according to departments;  apply different routing policies etc.Snapshot 4 : Oct - Nov 1997 Install redundant ATM backbone, redundant route/switch engines. Migrate servers to 100BaseT. Replace more hubs by ethernet-switches. http://www.awi-bremerhaven.de/EDVBrest Bremen© H.Pfeiffenberger AWI BremerhavenDeterminants of the Bremen MANPre-Liberalization Law¥ No competitor of D.Telekom able to provide all necessary lines => lease lines from D.Telekom and 3 public utility companies ¥ Complicated licensing necessary => let the former telephony department of the public administration run the network officially.Public finance and (no) sponsoring¥ Neither Telekom nor utilities willing to sponsor.¥ Senator for science and education out of money, but lets his people do the work¥ Lease and equipment plus 1 (one) person to do the ãAdidasÒ-type of netadmin payed for by Senators for economy and harboursOrganization¥ Steering headed by senatorial group¥ Working groups- Technics, netadmin (AWI,University) - Aquire projects (officials from senate) - Involve SMEs (consultancy firm)© H.Pfeiffenberger AWI BremerhavenHistory of the Bremen MAN1994: AWI and University of Bremen on the German science network (WiN) at 128 kBit/s each. AWI on the regional testbed (Northern Germany) for the broadband science network (B-WiN). Talks about an ATM based state network.Q1,1995: Decision to build ãLandesbreitbandnetzÒ, for two year initially. AWI responsible for technical concept and implementation. Jun 1995: Orders for leased lines and equipment.Oct 1995: Model network with equipment and short cables in the lab. Nov 1995: Roll out equipment to final locations Put long distance fibres into operation.Dec 1995: Workshop at Bremen University. Demonstrate connection to Bremerhaven (100 km of fibre, 4 ATM-switches). Build broadband IP network of scientific institutions.29 Feb 1996: Official opening. Demonstration of distributed engineering: DASA-Airbus Bremen, University of Stuttgart, BADLAB Canada, AWI.Apr 1996: Connect to B-WiN at 34 MBit/sNov 1996: Replace first generation ATM-switches (Cisco LS100) by second generation (LS1010)Nov 1997: Decision to operate network 3 more years.© H.Pfeiffenberger AWI BremerhavenComponents - Backbone, (ãCustomerÒ))ATM Switches: - Cisco LS1010, LS100 (Nortel, 3Com)IP Router: - Cisco 7000 ( 4700, 7500, Catalyst RSM)LAN-E Switches: - Cisco Catalyst 5000, 5500 (3000, 3Com)Leaf Nodes: - Sun- SGI- IBM-Workstations, - (Linux-) PCsNICs: - Fore- Sun- Olicom© H.Pfeiffenberger AWI BremerhavenParticipants (partial)Science¥ Alfred Wegener Institute¥ University of Bremen, esp. Institutes for- Informatics- Maritime Logistics- Applied Industrial Technology- Applied Space and Materials Science- Medical Visualization¥ Hospital¥ University Library¥ Technical Colleges (Hochschulen)Education¥ Schools¥ Adult Evening School¥ Public LibraryHarbours¥ Senatorial office¥ Port Authority¥ Ports DatacenterIndustry¥ DASA Airbus¥ Spin Off Centers

A distributed administration system for ocean simulation data

A distributed administration system for ocean simulation data

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