District Technology Infrastructure


Overview

District Technology Infrastructure deals with building and district level connectivity. To make effective use of the technology in place and to expand its use, the District will need to continue to develop the wiring infrastructure within each building as well as the connectivity between buildings. This will allow for increased communication across the district, sharing of information crucial for teaching/learning and administration, and promoting communication among all segments of the educational process.

Building Local Area Network (LAN)

Each building within the district currently has a data network infrastructure in place. This building level network consists of Cat-5 cables in each room. In a number of buildings the various wiring closets are connected by fiber. Over the years some of these networks have been modified and increased as needs were identified. LAN switches have recently been replaced in the elementaries, and the secondaries also will get new switches in 2005-6.

We are now at the point where LANs need to be renovated and upgraded. Key issues to address include:

  • Increasing the number of line drops per classroom in order to get higher bandwidth to individual computers.
    • Increase to (on average) six drops per room, plus two in the ceiling of each classroom to allow for wireless access points and networked LCD projectors
    • Increase LAN bandwidth to (at least) 100MB in all buildings and 1GB in specialized locations (media, etc.).
  • Preparing for technology convergence, where our network carries more than just computer traffic.
    • Use Cat-5e or Cat-6 cables to accommodate Voice over IP (VoIP) telephony and power over Ethernet
    • Use switches with Quality of Service (QoS) support so that voice traffic can be given a higher priority than computer traffic.

District Wide-Area Network (WAN)

As buildings developed their infrastructure, the District worked on establishing the connection between buildings, the wide-area network (WAN). At the time of the 1996 Technology Plan, a variety of options were considered, such as ISDN, Frame Relay, etc. The option of using the local cable company had not yet emerged. Since then, the District has worked closely with Sunflower Broadband to develop a WAN for the District. Over the years this system has been modified to accommodate new technology and increased demand.

Starting in 1999, discussion was held to develop a fiber network between the buildings. A five-year contract was initiated by the District and Sunflower Broadband to provide fiber to each building. By the fall of 2001, all buildings were connected by fiber. This new backbone gave the District expanded bandwidth and capabilities, and further enhancements are underway, as described below.

Information Technology Services Server and WAN Goals

Where We Are Now

We now have a gigabit Ethernet fiber optic ring connecting all District facilities. This is a 2-fiber ring so that we are protected against a single line cut. However, the back side of the ring sees less effective bandwidth than the side closest to ESDC.

The network is driven by a cluster of servers at ESDC. These servers have modulated power that comes in through an Uninterruptible Power Supply (UPS), protecting us from transient power fluctuations and brief (< 30 minute) outages. This is augmented with an onsite power generator to protect against longer outages.

The server cluster is connected to a Storage Area Network (SAN). A SAN is a special network made up of redundant hard drives that have a high-speed connection to the servers. It is separate from the normal network that user’s computers connect to. The SAN stores all of the data that would normally be stored on each individual server. This way when a server in the cluster fails, its data is still accessible to the other servers so that they can continue to provide the data to users via the cluster.

Where We Would Like To Be

The current ring topology has been reliable, but the shared bandwidth will soon become a limiting factor. To get around this, we have contracted with Sunflower Broadvision to implement Coarse Wave-Division Multiplexing (CWDM). This is a method whereby multiple colors (frequencies) of light are sent along the same fiber and peeled off one at a time as each building is reached. Thus, while we would maintain a physical ring, we would have a logical star, with each building essentially direct-connected to the server cluster at ESDC. This will improve bandwidth to schools (particularly to those far away in the ring) and also will improve reliability, as a building outage will no longer affect the schools beyond it in the ring.

The SAN has proven to be technically sound, but the system has proven to be woefully short of the storage needed. This is a reflection of the increased use of technology in instruction and the demands of storing larger data files, such as digital video. We have recently implemented a new SAN with roughly 20 times the storage capacity of our previous model. This provides far greater user storage space and also sets the capability to move to “blade” servers, where individual units no longer need to have dedicated disk drives. In conjunction with virtual servers (VM-Ware), we anticipate increased flexibility and responsiveness to user requests.

As a result of server and storage consolidation in ESDC, we have “hardened” that facility (as described above) in order to mitigate against outages. There is still some exposure in the event of a disaster (e.g. fire) and would like to improve our ability to recover from same. Our greatest exposure would be loss of data. Servers are utility devices and can be replaced fairly quickly. Data, on the other hand, is a unique product that may have required “person-years” of time to construct and cannot be easily re-constructed. To that end, we are planning to mirror the ESDC SAN offsite.

Technology Support Services

As networks are re-designed and upgraded, the support structure to maintain and run them needs to be examined to insure that adequate personnel are trained and available to maintain the system. It is the goal of the District to provide the necessary technical support by district personnel, but if necessary, outside consulting and outsourcing will be considered.

As we enhance our local-area, wide-area, and wireless networks, the issue of security and access will need to be continually examined. Access will be provided based on an individual’s need for specific information (i.e. instructional materials, student information, grades, etc.). Measures have been taken in order to secure sensitive data and will need to be continually re-evaluated as needs change or new threats emerge.

Recommendations

  1. Continue to refine the building level infrastructure. Adequate electrical and network wiring should be installed to allow instructional and administrative access to building and district data.
  2. Continue development of the wide-area network using the most cost-effective methods possible with the greatest-growth potential.
  3. Develop and implement a redundant SAN for disaster recovery
  4. Increase storage capacity to accommodate current and future needs. Continue to request that staff delete or achieve information regularly.
  5. Continue to provide necessary equipment, software, and training to allow district-wide network services and telecommunications capabilities.

Benefits

  1. A high-quality, well-managed network allows for cost-effective utilization of equipment across the District.
  2. A redundant site will allow for quick recovery from major disasters.
  3. A sound and stable system allows for expanded services that can be provided over the network (VoIP, teleconferencing, long-distance learning, etc.)