Appendix 4

Networking Plan: Requirements & Design

Highland Park Elementary School

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This document describes Highland Park Elementary School's networking requirements and the resulting network design developed by Digital Equipment Corporation and NETSERV.

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Contents

• Preface
• Networking Requirements
• Network Technology & Design
• Characteristics
• Network Wall-outlet Location
• Network Equipment
• Active Equipment and Distribution
• Outlets, Faceplates and Office Cables
• Network Components

• Appendices (List only for the on-line version)

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  Preface

  Claudia,

  Enclosed is the network plan for Highland Park Elementary. We have reviewed the Austin ISD Information Systems Architecture and made modifications to be fully compliant with these plans.

  On December 9, 1992, NETSERV and Digital were on-site at Highland Park to re-examine the cable plant design. The design now utilizes 10baseT twisted pair wiring. In addition, we have worked on the design to support:

  • Multiple taps in classrooms in a cost effective manner. The design specifies for wiring four (4) runs to each outlet and initially activating two (2) of them. Over time, activating more taps can be done simply by adding modules into the hubs.

  • In addition to wiring multiple runs to each outlet, the backbone has been designed to allow the use of 10baseT repeaters inside a classroom. Should a cluster of 4 or more devices need to reside at an outlet, a 10baseT hub can be plugged into one of the outlet's taps and fan out to more devices.

  • We have specified Category 5 grade twisted pair wiring. This assures that the cable plant being installed can scale up in the future to 100 Mbps networks such FDDI over copper.

  We look forward to working with yourself, NETSERV and the Technology Committee to finalize the details of this design.

  Curt Veteikis, David Korns, Ken Venezio

  Digital Equipment Corporation

  December 1992

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  Networking Requirements

  Computer networks can be built for many purposes and to satisfy a range of needs. It is always important to understand the requirements for a particular situation nad judge alternative technologies accordingly. The following requirements lead to the design of Highland park Elementary School's network.

  • The network should allow devices to be located in any of the classroom or lab locations defined in figure 2-1. This initially consists of 49 locations.

  • The network should allow for mobility of devices to be moved from location to location.

  • The network should allow multiple devices to be located in any of these locations. For example, 5 devices many be moved into a single location for special purposes or events. One of these locations will be the Media Center and computer lab where more devices will be located.

  • The network should:

    ---be standards based and support multiple protocols (AppleTalk, OSI, TCP/IP, DECnet, etc.)

    ---be easy to maintain and trouble shoot

    ---have the capacity for the larger traffic involved in multimedia instructional applications

  • The network should allow for future connection to TENET (Texas Education Network) via a router-based TCP/IP connection that can consolidate the traffic for multiple users within the school (as opposed to individual telephone calls).

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  Network Technology & Design

  The industry standard networking technology which best meets Highland Park Elementary's requirements is Ethernet (IEEE 802.3, OSI 8203). The flexibility in configuration, ease of maintenance, low-cost, and bandwidth are the characteristics that set it apart from the other industry standard choices (LocalTalk, Token Ring and FDDI).

  Ethernet/802.3 networks can be built using a variety of physical media including thick wire, thin wire, twister pair (shielded or un-shielded), fiber-optic and broadband coax (CATV). In addition, there are both bus and star topology options. The network design chosen for Highland Park Elementary is twisted pair (10baseT) in a star topology. The characteristics of this design relative to Highland Park Elementary's requirements are:

  Characteristics

  • The star wiring topology provides a very reliable and easy to maintain configuration. In Highland Park Elementary's (HPE) case, all the active components in the network will be located in two central hub locations where reconfiguration and trouble-shooting can occur.

  • Each of the drops will be equipped with a faceplate capable of handling four 10baseT MJ8 plugs. As a balance between future expansion and initial costs, we have decided to run wiring for 4 10baseT runs to each outlet. Initially, the outlets will have two of the plugs enabled. Future expansion can include adding the hub-end equipment for more of these taps to be enabled in the various locations. (NOTE: In the new Media Center, there are 6 outlets will WILL have all four plugs enabled at initial installation providing 24 active taps).

  • HPE requires the ability to put clusters of devices in any location configured with a wall-outlet. While each outlet will provide for 2 (or 4) active devices, there may be occasions requiring more devices connected to a single outlet. Since 10baseT Ethernet cannot be daisy chained, the solution involves small 10baseT repeater devices. These are sometimes referred to as hublets or 10baseT hubs. Street prices currently range from 300 to 500 dollars. A pool of these devices can be kept on hand to serve those occasions where additional devices are temporarily or permanently required. In order to accommodate these repeaters, the backbone system has been specifically designed to allow these additional repeaters without violating 802.3 repeater rules.

  • With the future in mind, the horizontal wiring between the central hubs and wall-outlets will be Category 5 un-shielded twisted pair wiring. There are currently 3 types of wiring in use. Category 3, 4, and 5. Category 3 is sufficient for 10baseT Ethernet at 10Mbps and would provide for all of HPE's current needs. Category 4 is used for 802.5/TokenRing at 16Mbps. Category 5 is specified for 100Mbps operation with networks such as FDDI.

  • The hub location (A/V Closet and CATV Closet)will be interconnected using industry standard 62.5/125 multimode fiber optic cable. The fiber will terminate into a fiber Ethernet bridge in each of the hubs.

  • All wiring and fiber is compliant with the EIA/TIA-568 Commercial Building Wiring Standard meaning the active and passive components will interoperate with other vendor equipment adhere now and in the future.

    With regard to bandwidth, network plans must always anticipate the future growth of users and applications. The use of computers and networks in K-12 education is exploding and applications we cannot envision today will be the norm in 3-5 years. Should the school's future networking requirements go beyond the 10 million bits per second capacity of Ethernet, the wiring and fiber being installed (Category 5 Un-shielded Twisted Pair) is capable of handling FDDI at 100 million bits per second. Upgrading to FDDI in the future would only involve new hubs with technology such as FDDI. New wiring.

  Network Wall-outlet Locations

  The following diagram shows the required locations for wall outlets. In addition, the location of the two hubs and which outlets are served by which wiring hubs is identified.

  Network Equipment

  Wiring hub closets for the local area network will utilize Digital's DEChub 90 Work group hub products. This device has slots for 8 (or 16) cards which support various LAN media and functions. Cards available include twisted pair repeaters, terminal services, bridges, routers and thin wire repeaters.

  Active Equipment and Distribution

  The hubs will be located in the A/V Closet and the CATV Closet. To conserve space, they will be wall-mounted and not require a free standing rack. The DEChub and patching will protrude only about 1 foot from the wall.

  The hubs will be configured with DECrepeater 90T's (8 twisted pair ports each) and a fiber optic bridge to connect the hubs together. This configuration is depicted in the following two diagrams of the active equipment and panels. (NOTE: a bridge is configured to allow 10baseT repeaters to be used in classrooms without violating 802.3 repeater limit rules.

  The DEChub 90 can be configured with an optional lockable cover that secures the modules and patch panels. When using this cover the hubs would be placed side-by-side (as opposed to stacked), each with it's own lockable cover. Utilizing the locking covers allows the closet to be accessed by non data network personnel without security concerns.

  Physical wall space in the two closets may influence which arrangements will be required.

  The patch panel will be the termination point for each of the 49 wall-outlets (196 taps) installed in the building. Short patch cables then connect active wall-outlet taps to one of the DECrepeater 90T ports. In this way, classrooms could be re-configured around a bad port.

  This configuration leaves room for 15 DEChub 90 cards for expansion. Expansion could include additional active ports for classrooms (DECrepeater 90T modules). SNMP network management ability (DECagent 90 module),, or connecting to wide area networks such as TENET (DEC WANrouter 90 module or future DEC/Cisco router).

  Outlets, Face-plates and Office Cables

  Each of the 49 locations will be equipped with an outlet. Outlets in most locations will be a wall box type. As part of the new construction in the media center, flush wall mounted face-plates will be used. In addition, a supply of 50 office cables will be provided to connect devices to outlet taps. Both wall-outlets and office cable components are pictured in diagrams in the appendices.

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  Network Components

  The following Digital parts are required for the solution described in this document.

  Quantity/Part Description

  • A/V Closet Hub: Supports 26 face-plates and patching for up to 104 active taps. Initially will have active ports for 64 taps (2 per face-plate, 4 per face-plate in Media Center).

    2 DEHUB-BA DEChub 90 w/power

    1 DEWGF-MA DECbridge90FL (no power)

    8 DETMR-MA 8 port 10BaseT repeater (no power)

    2 H3108-BA Patch panel frame w/6 inserts

    12 H3107-L Patch insert 110-type punchdown

  • CATV Closet: Supports 24 face-plates and patching for up to 96 active taps. Initially will have active ports for 48 taps (2 per face-plate).

    2 DEHUB-BA DEChub 90 w/power

    1 DEWGF-MA DECbridge90FL (no power)

    6 DETMR-MA 8 port 10BaseT repeater (no power)

    2 H3108-BA Patch panel frame w/6 inserts

    12 H3107-L Patch insert 110-type punchdown

    Faceplate Components: All faceplates will be Modular Office Wallboxes except those in the Media Center which will be Modular faceplates.

  • For Media Center drops: (6 drops in total, 24 10BaseT taps)

    1 H3111-C Modular faceplate w/blank inserts, kit of eight

    4 H3112-F Snap Connectors UTP w/data icon, kit of eight

  • For classrooms and other drops: (44 drops in total, 176 10BaseT taps)

    6 H3111-GC/CDB Modular Office Wallbox w/blank inserts, Ivory, kit of 8

    24 H3112-F Snap Connectors UTP w/data icon, kit of eight

  • Miscellaneous:

    50 BN26K-03 8-pin Mud Plug cable, 10 ft. length

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  Appendices (List only)

  • DEChub 90 Multifunction 802.3/Ethernet Backplane

  • Wall-Mount Plate and Cover for the DEHUB-AA

  • DECrepeater 90T Workgroup Multiport 802.3/10baseT Repeater

  • DECbridge 90FL Fiber Optic Ethernet/802.3 Bridge

  • 10baseT Patch Panel Insert Kit

  • DECconnect Modular Faceplate

  • DECconnect Modular Office Wallboxes

  • 10baseT Office Cables