User Tools

Site Tools


kb:tech_levy:infrastructure

Infrastructure

<columns>

<newcolumn>

Background

Infrastructure for the purposes of this proposal will refer to the primary network components that support our entire technology operation extending from our connection to the internet to the internal distribution wiring that services the user desktop. The components are as follows:

Device/Component Role What It Does How many
Firewall intermediary device between internet and internal network block hostile intrusion and provides content filter in compliance with CIPA5
Routers “gatekeeper” controls access segment network into smaller “subnets” for improve manageability and security 4
Ethernet Switches network distribution connects rooms and other areas to backbone via CAT 5 20 excludes classroom level)
Fiber Optic Cable “backbone” the distribution medium between buildings has the capacity to transport large amounts of data using laser lightN/A
Cat 5 cable copper cable distribution medium to network periphery allows network connections in classrooms and other areas N/A

Network Diagram

Current

The fiber optic cabling throughout the district was installed in 1998. The type of fiber is called “multi-mode” which at the time was the only affordable option and was more than adequate to support our needs. Fiber cable runs between all schools and at VHS between all buildings. Fiber cable is necessary for such long cable runs because CAT 5 does not support distances greater than 300 ft. Multi-mode fiber has a data carrying capacity measured in megabits 10MB-100MB). Since fiber utilizes light to transmit data we must convert light back into electrical signals and vice versa at points along the backbone in each building. We currently use standalone devices called media converters to do this.

In most instances data goes from the backbone through our routers and is passed into the local network (LAN) in each school/building. Our routers are what are known as Layer 3 switches that function also as routers. Technically they are Ethernet switches that can do routing (a layer 3 protocol.) Data then goes from the routers to Ethernet switches which distribute data to rooms and ultimately to the desktop. In some instances we do some switching at the room level where there are multiple computers with limited data jacks. All libraries and computer labs are done this way. Switches are also employed to create VLANS (Virtual Local Area Networks) which allow us to further segment the network when it is not possible to physically separate them.

Costs

Device/Component Cost Comment
Firewall $2,000 We use opensource (software) firewalls that are built out of standard computers (hardware) and will continue to do so. We will upgrade the systems these are built on
Routers $10,000 We will move to enterprise class hardware based routers
Ethernet Switches $20,000 Replace and migrate current switches out to periphery (classrooms and labs) and install gigbit switching devices in our core areas
Fiber Optic Cable $0 Install Singlemode fiber on all major runs and some internal building locations (libraries-labs) Will be part of Bond Proposal
Cat 5 Cable $20,000 Add additional internal cabling at CES and McM with limited additions at VHS (See note #1 below)
Uninterpreted Power Supply (UPS)$8,000 Upgrades to our power backup in IDF lcations in each school.
Note #1
Why not use wireless instead of additional Cat 5?
We plan to make extensive use of wireless technologies as we move forward but core network distribution from a bandwidth, management and security perspectives must rely on the “wired network”. This is still considered an industry “best practice” which we will continue to use for many years

</columns>

Rationale

When our network was built in 1998 our data needs were modest however, in the last ten years our capacity and utilization has grown enormously. We now use video conferencing on a regular basis, streaming medium as a regular part of instruction in the classroom, Voice Over IP (VIOP) phone service at the District office and offsite data services (student/fiscal management) all requiring greater bandwidth. In addition to these high bandwidth services we simply have more devices connected to the network. As more devices are connected the “utilization” of available bandwidth internally increases causing service interruptions and other problems. Since we are moving in the direction of thin client computing good connectivity is critical to smooth functioning.

Much of what we have done with respect to infrastructure over the years has used “commodity” or “medium-size business” class equipment. This was done for a number of reasons: affordability and it fit our needs. The state of our systems and where we are likely to go in the next 10 years requires us to move into the “enterprise” class of devices and infrastructure to not only meet demand but to insure high reliability. In addition to instruction our business operations are heavily dependent on solid reliable connectivity. Enterprise level systems also will insure greater security for our systems as we move forward. In short we will be moving from gigabit megabit 100Mb/sec speed to 1000Mb/sec in all key devices attached to the backbone.

~~DISCUSSION~~

kb/tech_levy/infrastructure.txt · Last modified: 2019/03/21 11:50 (external edit)