Anton Gerold, Rupert Gnatz
The extensive computer network at the Fakultät für Informatik primarily uses UNIX workstations. Originating from 1983, the network was based on 10 MBit Ethernet technology. Meanwhile network technology has improved a lot, so that ATM (155 MBit) and Fast Ethernet (100 MBit) networks are now used for the backbone.
The computers for research and teaching are either positioned decentralized in separate pools at each chair of the Fakultät für Informatik, or installed centrally. The systems at the chairs typically comprise the scientists' workstations, workstation pools assigned to graduate students, the servers for that chair, as well as experimental and/or special systems. The central systems include workstations for the basic training in computer science, workstation pools for all students and central servers for software supply, email, modem access, ftp archives and information systems like NEWS or WorldWideWeb (WWW). A service may be provided by many machines (distributed), which can be located anywhere within or beyond the institute's LAN (worldwide distributed like WWW or just within the institute like the digital library system OMNIS/MYRIAD).
At the beginning of their studies, undergraduate students of computer science get a login for the central workstation cluster of the institute, which remains valid during the whole time of their study. If they have to use a chair's workstations, graduate students usually get an additional permit. The possibility to work via network on a remote workstation saves the students a lot of time, since some chairs are distantly located and they don't have to go there everytime in person.
Members of staff always have access to the central workstation cluster and to the workstations of their chairs.
The systems - hardware, software as well as the network - are principally
maintained by a special team, the "Rechnerbetriebsgruppe" (RBG)
of the Fakultät für Informatik. This team closely cooperates with the
system administrators of the chairs. Apart from administration and
maintenance, they are also responsible for purchase, installation and
set-up of new equipment.
Hardware
The workstations used at the chairs for scientists and students, as well as their servers are mainly SUN, HP, SGI and DEC systems. DEC-Alpha and IBM workstations have been acquired for research projects.
Nowadays, the computer market offers only workstations with colour monitors. Regarding their professional usage, colour monitors with large diameter and high resolutions and refresh rates are preferred. At the chairs located at the Ostbahnhof, monitors have to be shielded against electromagnetic disturbance, caused by passing trains.
Software complexity today requires a minimum of 32 MB RAM, tending towards 64 MB and more. Due to these requirements and a decrease in prices for storage media, the total amount of RAM and diskspace installed at the institute has been doubled over the last two years: 32.6 GB RAM (1995: 15 GB) and 1.32 TB hard disk capacity (1995: 0.65 TB).
At the moment the RBG is in charge of almost 1200 workstations, PCs
(some with special peripheral devices), notebooks, etc. They also
maintain around 2400 IP addresses (including those for dialup access
via PPP).
At the institute the following special computer systems are installed
for experimental and research purposes:
From its start the RBG has been assembling computers. In a very dynamic market for hardware components, members of the team are successfully building high performance computers (e.g. Pentium dual processor systems) at moderate prices. These computers can be run under UNIX as well as Windows NT. Very good experiences have been made with Solaris x86 2.5. The fact that the RBG is assembling the computers by themselves has a lot of advantages: the development of technology and market trends of the component sector are carefully observed, further the knowledge of the team is continually updated and costs are reduced. So 185 of the 1200 computers have been built by the RBG in the last two years.
For undergraduate students of computer science, a cluster of 110 HP 9000/720 workstations has been installed in the "Informatikhalle" in the "Robert-Sauer-Building" (see map) since August 1991. Eleven additional workstations are used as servers for software and user data. This cluster has been extended by SGI Indy workstations in 1995/1996.
The HP cluster was set up to replace a mainframe. At that time this concept was new, but it has proved to be successful until today. Due to its modular composition, such a workstation cluster can be expanded flexibly or upgraded step by step.
During the off-hours, when the cluster is not needed for teaching, it is often used for research on distributed and parallel computing.
The HP cluster will soon be partially replaced with focus on
multimedia oriented workplaces, increase of performance of
the entire system and multiprocessor systems (SMPs) as
incentive for the development of parallel programs.
Software
In the institute's LAN, various UNIX variants of the different computer manufacturers are used as operating systems. Exceptions from this rule originate from special research and teaching projects.
The graphical user interface used is X11. Instead of the heterogenous interfaces provided by the different manufacturers, the RBG managed to offer a homogenous user interface on the UNIX systems supported by the RBG. This homogenity of the user interface and of the operating system (UNIX), makes it easier for the users to move between different computer systems at the institute's LAN. This mobility is enhanced by the large supply of public domain software (GNU, TeX, etc), which is provided in a uniform way on the supported systems. The crucial advantage of PD software in research and teaching is the fact, that the source code is in most cases accessible.
For this reason and because of cost considerations, we prefer PD
software if it offers the necessary functionality in combination
with good quality and stability in daily usage.
If this is not the case, or if special demands arise from certain
research or teaching projects, commercial licensed software is
used.
Network Design
The logical design of the institute's computer network (see figure) generally supplies a subnet for each chair and for the central area. The network design is characterised by the fact, that the chairs are distributed in seven different locations all over the city, some chairs are even divided into more than one building.
The institute's LAN is based on a 155 MBit ATM backbone connecting the central HUBs of the different locations with fibre optic cables. Ethernet switch cards are integrated into these HUBs which are connected via ATM backplane. Each chair's computers form local clusters and are connected to the HUBs, directly or via workgroup switches. Additionally a Fast Ethernet infrastructure has been established connecting the main servers as well as the chairs of the Fakultät für Informatik and some chairs of the Fakultät für Mathematik (faculty for mathematics).
The institute's LAN is connected via the LRZ (Leibniz-Rechenzentrum,
Leibniz Computing Centre of the Bavarian Academy of Sciences) to
the entire computer network of universities in Munich and to the
WIN (the german science network). This connection is using
Fast Ethernet, as well.
Peripheral Devices
Laser printers with postscript, as well as matrix printers are at the disposal of all chairs and the students' workstation pools. There are some colour printers available for special purposes, but due to the high costs of purchasing and operating, the institute currently maintains only few colour printers.
Standard peripheral devices for use with the computers at the institute are floppy disk and CDROM drives as well as DAT tape streamers. Some workstations are equipped with scanners. With their help books and other documents are recorded for the archive/library system OMNIS/MYRIAD.
Depending on the scientific interests of the chairs, special purpose peripheral devices are beeing used (e.g. in robotics).
Lately it has become necessary to provide several workstations
with audiovisual equipment (such as video cameras, video players
and recoders, etc) - a necessity that will increase in the near
future.
Multimedia Lecture Room
To increase the use of multimedia techniques in teaching, during 1996/97 a multimedia lecture room was installed. The equipment allows to record and replay video and sound in TV quality (PAL/component analog) as well as transfer between TV and computer systems. The video projectors and audio devices are remotely controlled from a control studio next to the auditorium. Transmissions from or into the lecture room are possible via Ethernet, ATM or ISDN (in different quality, resp.).
First experiences show how to extend and improve this installation. Because of the high costs, full digitalization of video and audio signalstreams is still not realized, although our institute would prefer such a solution.
Long-term plans are on the way to complete the multimedia lecture
room and its control room with a multimedia laboratory, which
should support the preproduction and postproduction of
audiovisual material. In the future a video server may be installed,
that would allow multimedia workstations in the network to access
this material (lecture on demand). The multimedia lecture room is a pilot project of the university and
has attracted the attention of several other universities.
Dialup Access to the Institute's Network
Currently there are 31 modem ports with a bandwith of 33.600 bps (V.34) each for remote access. They can be used by staff as well as by students. 19 of these support PPP-connections, since more and more users choose this type of connection. In 1996 30 ISDN basic channels were set up for PPP connections and their overall usage exceeds already a quarter of their capacity.
So it is possible to use the institute's computer equipment seven
days a week, 24 hours a day from home.
World Wide Web
The main server of the Fakultät für Informatik has the URL:
which is the entry point for the presentation of all the different teaching and research facilities of the institute.
In close cooperation with the central office for information of the Technische Universität München, the Fakultät für Informatik also maintains the main WWW server of the university:
LEO - Link Everything Online - is an electronic archive which is essentially maintained by the Fakultät für Informatik and which is gaining world-wide attention, as the number of visitors is currently about 7 million per month.
Management of the "Rechnerbetriebsgruppe"
Director: Prof. Dr. Chr. Zenger
Head of staff: Dr. A. Gerold
Assisting: Dr. R. Gnatz, H.-O. Riethmayer
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Copyright © 1998 Institut für Informatik, Technische Universität
München
Alexander.Bock@informatik.tu-muenchen.de
Last update: 1998-05-22