G-WiN – the Gbit/s infrastructure for the German scientific community
Introduction
The German National Scientific Networking Association, Deutsches Forschungsnetz (DFN), commenced operation of its gigabit network – G-WiN – in June 2000. The main aim of this paper is to describe the basic concepts, technical structure and services, status and future extension plans of the implementation of G-WiN for the DFN community. Before describing these new network facilities, some information on the status of the current network, B-WiN, which has been available to the DFN community for 4 yr, will be given. Activities during the network planning and preparation phase for G-WiN will also be discussed.
The current network, B-WiN, is based on ATM technology. The IP services are provided on top of the ATM platform. Access capacities have so far been provided by DFN ranging from 128 Kbit/s to 155 Mbit/s. In November 1999, about 600 sites were connected to B-WiN, sharing about 100 access links of 34 or 155 Mbit/s. International connectivity consisted of 622 Mbit/s (4×155 Mbit/s) to US internets, 155 Mbit/s to the pan-European network TEN-155 and small connections to Russia and China. In June 2000, international connectivity to US internets will be increased to 2×622 Mbit/s in preparation for G-WiN.
In 1998/1999 two regional Gbit/s infrastructures, so-called gigabit test beds, were implemented in order to test and run new applications requiring high bandwidth in preparation of the new gigabit network.
Section snippets
Reasons for a Gbit/s network
Setting up a Gbit/s network for the DFN member institutions is essential. The exponential growth in transfer volume indicated the need for a gigabit network as a transfer platform for the DFN. New innovative applications like multi-media require higher throughput and more meticulous communication profiles especially higher peak rates.
In the framework of network design the following investigations were carried out in order to define demands on the network.
Qualitative demands:
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Analysis of traffic
Procurement
In the second half of 1999, a European tender for network components was carried out. Deutsche Telekom/DeTeSystem AG was selected as the supplier of the SDH/WDM service for the G-WiN backbone. For the access lines, several suppliers were selected. The tender for G-WiN routers was made for Cisco routers only because of a Cisco donation and to enable the continued use of the Cisco routers used in B-WiN. Routers of different manufacturers should not be employed by reasons of network management.
G-WiN architecture
The structure of G-WiN is shown in Fig. 1. The SDH/WDM backbone nodes consist of SDH and WDM devices as well as the G-WiN Cisco routers and ATM switches. Both the IP and the ATM networks are realised on top of the SDH/WDM layer. Customer routers or customer ATM switches, located at the customer premises, are connected by access links to the backbone nodes.
G-WiN services
G-WiN provides the following services [3]:
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IP service with access capacities of 128 Kbit/s, 2 Mbit/s, 34 Mbit/s, 155 Mbit/s, 622 Mbit/s up to 2.4 Gbit/s;
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Point-to-Point service with capacities of 2 and 34 Mbit/s;
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ATM service with access capacities of 2 and 34 Mbit/s (155 Mbit/s in special cases).
Overview
The SDH/WDM backbone consists of 29 nodes most of which are located on university premises. The nodes comprise SDH multiplexors and WDM add drop multiplexors (ADMs) as well as IP routers and ATM switches in some cases. In Fig. 2 the initial backbone topology of the G-WiN DFNInternet Service is shown. In the following sections, the technical implementation of the G-WiN services is described.
IP service DFNInternet
The configuration of the IP network consists of 29 router nodes connecting the customer routers by access
Tariffs
The rates for the DFN services, DFNInternet, DFNATM and DFNConnect were decided on the principle of cost sharing with rates independent of the customer's location. The rates are dependent both on access capacity and average monthly throughput. The tariffs are published in [4].
Start of operation
The first backbone node, with some connected customers, was running during the Cebit Hannover Fair to present new applications with high bandwidth requirements. G-WiN commenced its operation in June 2000. The level-1 SDH/WDM G-WiN backbone as well as the level-1 router network with its connected customers are currently in operation. Connectivity to customers remaining on B-WiN is provided by 10 Gateways. The increased capacity for international connectivity is still to be delivered. Work is
Outlook
The signature on the G-WiN contract with DeTeSystem/Deutsche Telekom AG in October 1999, and the planned fast implementation of the initial configuration formed the basis for putting G-WiN into operation in June 2000. G-WiN is implemented using the latest SDH/WDM technology and provides an appropriate platform for traffic growth and new applications. Through G-WiN, the German scientific community has at its disposal a gigabit communication infrastructure that technically equals the most
Acknowledgements
I would like to thank everyone involved in the planning and design of G-WiN as well as those who participated in traffic measurement and made available statistics on B-WiN traffic needed for the design of G-WiN.
Gertraud Hoffmann is member of the G-WiN network planning group of the DFN-Verein (Deutsches Forschungsnetz). She is responsible for the technical design and implementation of G-WiN and supervises DFN research projects in the field of network technologies as well as in optimisation of network design. She received her diploma in High Energy Physics from the Humboldt-Unversity, Berlin in 1966. In 1973 she obtained her Ph.D. in Computer Sciences. Since 1990 she has been involved in the evolution
References (4)
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- E. Jessen, The DFN Gigabitwissenschaftsnetz G-WiN, Workshop on Wide Area Networks and High Performance Computing,...
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Gertraud Hoffmann is member of the G-WiN network planning group of the DFN-Verein (Deutsches Forschungsnetz). She is responsible for the technical design and implementation of G-WiN and supervises DFN research projects in the field of network technologies as well as in optimisation of network design. She received her diploma in High Energy Physics from the Humboldt-Unversity, Berlin in 1966. In 1973 she obtained her Ph.D. in Computer Sciences. Since 1990 she has been involved in the evolution of WiN as a member of the technical staff of the DFN-Verein. During the period of setting up and piloting EuropaNet, she participated in this group as the representative of the DFN-Verein. Before 1990 she worked in the fields of network architecture and design and network implementation at the Academy of Sciences of the former GDR (East Germany).