Swiss Utility Centralizes Resources and Builds an ATM Network

Swiss Utility Centralizes Resources and Builds an ATM Network

By Francois Marechal, Services Industriels de Geneve

As utilities worldwide struggle to improve services while containing costs, networking technology becomes increasingly important. The flexibility to support emerging applications must be balanced with the costs of upgrading network infrastructures. Utilities are faced with tradeoffs between supporting immediate business applications and building infrastructures that will support long-term business requirements.

In an effort to address both immediate needs and long-term business goals, Services Industriels de Genàƒ¨ve (SIG) decided to plan and build an advanced information network infrastructure. SIG is the public utility which supplies all water, electricity, natural gas and steam heat to Geneva, Switzerland. SIG delivers more than 60 million cubic meters of water and 2.5 billion kWh of electricity to 250,000 customers annually.

In 1990, SIG management decided to centralize the majority of staff operations onto one large site. With staff spread out over nine sites and 40 different buildings, operations had become difficult to coordinate. An unused gas production plant was razed and replaced by a modern industrial campus consisting of three office towers (each six stories high).

Like many utilities, SIG was faced with the need to deliver more bandwidth to support emerging applications. A new high-speed LAN infrastructure was required to meet long-term network demands. SIG chose asynchronous transfer mode (ATM) technology with the help of Bay Networks for routers, switches, hubs and network management systems.

Emerging Applications Require More Bandwidth

Centralizing operations created the opportunity to evaluate bandwidth requirements and build a network infrastructure that could support future applications for additional users. SIG decided to base the network infrastructure on industry standards to ensure interoperability and maintain low operating costs. Management quickly ruled out fiber distributed data interface (FDDI) because of the inherent costs, the operational complexity and lack of scaleability. Fast Ethernet was also ruled out because the technology could only provide an intermediate solution and would not address future needs.

SIG determined that they could cost-effectively deploy an ATM backbone network that would have the flexibility to support new users and applications. In addition, it would have the scaleability to deliver more bandwidth to the desktop or support remote users. In early 1995, SIG awarded a contract to Teleinform–a local systems integrator providing network solutions consisting of hubs, routers, ATM equipment and network management. Together, SIG and Teleinform selected a complete networking solution based exclusively on Bay Networks equipment.

ATM Backbone Infrastructure Installed Quickly

Eight hundred users were scheduled to move into the three towers during a single week in September 1995. All LAN traffic in the towers would be Ethernet, with horizontal cabling leading to a wiring closet on each floor. The LAN traffic would then be consolidated onto an ATM edge device in each tower, and the towers would be interconnected over an ATM backbone. In addition, the servers and host computer in the information center would be connected to the ATM backbone to optimize network performance.

Teleinform installed the network on schedule, and the network was running reliably and efficiently when the users moved to the campus. A distributed 5000 hub was installed in each wiring closet to consolidate this LAN traffic and provide the flexibility for user moves, additions, and changes. Each of the three towers has a telecommunications equipment room with connections to each wiring closet. Traffic from the distributed 5000s is collapsed onto an EtherCell switch which converts the Ethernet frame-based traffic to ATM cells. An EtherCell in each of the three towers feeds into a 5000AH network center platform, which has an integral ATM switching engine. Traffic on this core network is switched at 155 Mbps. Since all backbone traffic flows through the 5000AH, a backup unit is connected to ensure redundancy.

The host computer and a variety of UNIX and office automation servers are located in the information center and feed into dedicated ports on an additional EtherCell switch. Each EtherCell is connected to the 5000AH, providing high-speed switching of server traffic over the core ATM backbone. There is also token ring traffic bridged over the backbone network for accessing legacy applications.

Virtual LANs Improve Work Group Performance

The physical topology of the network has provided SIG with the flexibility to view the network as four logical networks serving four distinct groups of users. By segmenting the physical network into four logical work groups, network performance is improved by isolating much of the traffic within the logical work groups. The virtual LANs (VLAN) required to accomplish this were designed using the ATM forum LAN emulation (LANE) standard, which was implemented in the network equipment.

SIG`s information technology (IT) group identified four different groups of users who would be put on separate logical networks but share the common physical infrastructure. The technical/administrative network consists primarily of office workers using desktop applications, such as electronic mail, databases, word processors, spreadsheets, inventory management and accounting. The development network is used largely by the IT department for developing and testing new client/server business applications.

The other two networks are mission-critical production environments. The real-time network consists of distribution applications for managing the delivery of water, gas and electricity to Geneva. The spatial imaging network primarily runs computer-aided design applications, which superimpose the distribution network onto topographic and survey maps. These networks require high degrees of reliability and large amounts of bandwidth to communicate image and video across the backbone.

A virtual network routing (VNR) card was recently deployed within the 5000AH chassis, providing a different virtual circuit for each VLAN. The VNR features are used to interconnect the various VLANs while effectively filtering out all unwanted inter-VLAN traffic.

Centralized Management of Local, Remote Connections

The computing environment is managed via IBM`s NetView 6000, and the communications equipment is controlled via the Optivity suite of the network management tools from Bay Networks. Optivity manages both the equipment in the central campus and the routers in remote locations. Ten remote sites are linked onto the network over 256 kilobits per second connections.

Larger remote sites, such as the hydroelectric plant on the Rhone River, have an access stack node router which is modularly expandable to support more connections. Smaller remote sites, such as the electric transformer stations, have an access node hub for both LAN consolidation and multi-protocol routing connectivity. These sites are connected to the 5000AH at headquarters using the VNR functionality (see Figure).

Optivity delivers software upgrades to both the local and remote communications equipment, allowing SIG to maintain the equipment with a relatively small network operations staff. Optivity will increasingly allow users to monitor and control the network from a single site while providing the utilization information needed to cost-effectively plan for any future upgrades.

Future Plans Require More Bandwidth

SIG plans to increase network flexibility by upgrading from EtherCells to Centillion 100 SpeedSwitches. This will provide additional flexibility to support higher bandwidth to the desktop. Coming soon are a number of new applications that are going to need the bandwidth provided by ATM. The spatial imaging network, for example, will be adding several multimedia workstations for mapping. Currently, geographic mapping of the utility grids is overlaid on local maps in two dimensions, but the system will evolve to provide three-dimensional viewing of maps.

Sophisticated shared media hubs, effective frame-to-cell conversion and ATM switching on the backbone have provided SIG with a network infrastructure that is flexible and scaleable enough to accommodate any new application requirements. The equipment has allowed SIG to cost-effectively build a network in a short time frame that will support future bandwidth requirements. And since all of the equipment is managed from a single location, the network can be efficiently maintained while supporting any additional applications which might be added in for the future.

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Global Trends in Utility Networking

By Olivia Hecht, Bay Networks Inc.

ompetitive pressures resulting from privatization and deregulation are forcing the need for greater efficiencies, and the communications network is being increasingly viewed as a strategic asset. Franàƒ§ois Maràƒ©chal and his colleagues at Services Industriels de Genàƒ¨va (SIG) have experience with many of the trends affecting utilities today and are on the leading edge of networking technology.

As a result of changes in the utility industry worldwide, new applications and technologies that increase productivity are currently being developed, tested and deployed. Many of these applications require multimedia connectivity. In the past it was often enough to provide connectivity utility-wide for voice and data. However, these emerging applications require transmission of images and video in real-time. These types of multimedia applications create demands on network capacity, and utilities are faced with expanding capacity or implementing an entirely new network.

As SIG was facing this issue, it was also facing the consolidation of remote sites into a new facility, which provided the freedom to design a network infrastructure for the long-term. However, many utilities are faced with connectivity with legacy infrastructure and equipment, necessitating a more gradual upgrade path to newer technologies.

A number of utilities facing these decisions are migrating to asynchronous transfer mode (ATM) for backbone networking because of its flexibility and scaleability, as well as ATM`s inherent ability to support multimedia applications. SIG chose to implement 10 megabits per second (Mbps) Ethernet networking to the desktop, because it did not yet have the bandwidth requirements demanded by multimedia. But SIG designed the network so higher-speed connectivity using Fast Ethernet (100 Mbps) or ATM (155 Mbps) could be delivered by modular changes to the switching equipment.

Most utilities provide router connectivity to remote locations, and many are evolving to higher-speed switching on the network backbone. Performance is always critical, so more and more utilities will follow SIG and develop Virtual LANs, which isolate users into logical work groups. Many utilities face these challenges even as they face headcount constraints, particularly in network operations. By implementing network management tools, SIG is able to optimize the network and quickly identify any potential problems. There has been an increased demand for robust network management tools by utilities as the complexity of the network increases at the same time the headcount decreases. Further, network management tools, which can provide network utilization statistics and departmental level billing information, are in high demand.

This new age of competition has forced some utilities to examine alternate lines of business to increase potential revenue sources. Using existing communications network infrastructure to support innovative applications and business initiatives places significant additional demand on the backbone network. It therefore becomes critical to evaluate both existing demands and long-term application requirements so the utility can cost-effectively build and operate a backbone network to transport mission-critical applications across the enterprise. Shared media hubs, frame-to-cell conversion and ATM switching are key technologies which support the evolution of utility networks, with routers becoming the dominant means of connecting remote locations.

Just as SIG evaluated requirements and carefully developed a network strategy based on multiple networking technologies, utilities worldwide are facing the same issues and are deploying high-speed networks under common management and control to deliver the applications needed to succeed in a competitive environment.

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Geneva, Switzerland`s utility, SIG, chooses ATM as its network core.


  • The Clarion Energy Content Team is made up of editors from various publications, including POWERGRID International, Power Engineering, Renewable Energy World, Hydro Review, Smart Energy International, and Power Engineering International. Contact the content lead for this publication at

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