Beyond that size the network must be subdivided using "subnetworks."  Design of a such a system is not difficult, but is beyond the scope of this
document.

The network distribution system cabling should include unshielded
multi-pair trunk cabling as well as ethernet trunk cabling.  The
multi-pair trunk cable will be needed to connect terminals or older
computers emulating terminals to a central "network access

___________________________________________________________
[10] If fiber optic cable is installed, consideration should be given to
     including both multimode fiber for current and future data requirements
     and single mode fiber for video and future very high speed data systems.

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server" (NAS).  A typical NAS can serve from 8 to 128 such
connections.  It is most cost effective to provide one per LAN, if
needed.  The NAS connects directly to the ethernet LAN.

1.4  Local Network Server

It is highly recommended that each school install a "network
server" to support local storage of commonly used information,
software, electronic mail, and other functions that may require
high speed communication to the user s computer.  Since the
connection to the outside network will be much slower than the
school LAN, it will be most efficient to access information locally.
In particular, software that is to be shared among the school s
computers must be stored locally since it would be very tedious to
transfer it across the slower external link.  The network server will
be connected directly to the ethernet network.

The location of the server should be chosen carefully to ensure its
protection from abuse and environmental damage.  Traditionally
the school library is the focus of information gathering and storage
activities and many school libraries have clusters of computers or
terminals already installed.  The library would be a very logical
place to locate the network server computer.  The Network Router
(see below) might also be located there if a suitable utility space is
not available.

The network server will be a small but powerful computer with a
large amount of disk storage capacity, typically 1-4 gigabytes.  It
will run software capable of supporting access by a large number of
users simultaneously.  It could also support dial-in access from
teacher s or student s homes using standard inexpensive modems. [11]
If more than a few modems are to be installed, a NAS might prove
more cost effective.  If dial-in access is to be provided to more than
a few school sites within a district, a single central modem pool
maintainted at the district offices will be the most cost effective.

1.5  External Connection

A single communication circuit will connect the school LAN to the
local school district offices.  In the school, there will be a Network
Router attached between the LAN and this circuit.  On the LAN
side, the connection will be a typical ethernet cable.  On the
external side, the connection will depend on the type of
communication circuit used, as discussed in step 2 below.

_____________________________________________________________________________
[11]  Access control with user authentication is essential if dial-in service
        is to be provided.

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Step 2: Interconnection of Schools with District Offices

All schools within a district should be connected individually to the
network router at the school district offices.  This "star topology"
will be much easier to manage and will minimize conflicting use of
the rather low communication bandwidth initially available.  As
needs change, the capacity of each school s connection can be
increased appropriately.

Several standard communication circuit services may be used to
effect this connection.  The least expensive will be dial-up using
high speed modems.  However, this type of connection is not
recommended due to its very limited speed.  Dedicated
(permanently installed) communications circuits are strongly
recommended since they will allow unattended access to and from
the school network at all hours.  This will be particularly
important if information files are to be down-loaded during the
night to local network servers.  Table 2 shows the most common
options for dedicated circuit services.  The exact costs must be
determined by contacting local circuit vendors.

Type of Circuit                 Data Rate                       Relative cost
-----------------------------------------------------------------------------
Voice grade leased              20 kilobits per sec             modest
telephone line                   (Kb/s)

ADN-56                          56 Kb/s                         high

ISDN, where                      64 or 128 Kb/s                 modest
available

Low power radio                 64 to 256 Kb/s                  high startup
                                                                cost

DS1                             1.5 megabits per sec            very high

_____________________________________________________________________________
Table 2: Short Distance Point-to-point Communications Options

Future options for interconnecting schools and district offices will
include[12] :

o       "Switched 56" service, providing dial-up digital
        connections at 56 kilobits/second,

______________________________________________________________________________
[12] Many more options will become available as new technologies come
     to market.

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o       "Frame Relay" providing packet switched data transport
        services at speeds up to 1.5 megabits per second, and

o       Switched Multi-megabit Digital Services (SMDS)
        providing data transport services at speeds up to 34
        megabits per second.

The costs for these options are unknown at this time, but may be
generally higher than those indicated in Table 2.

As demands for network speed develop due to heavy use of
multimedia or other bandwidth intensive application, higher speed
communications circuits can replace the initial circuits with little
or no change in the equipment or LAN.  This gives great flexibility
in tailoring service to funding levels and application needs.

Step 3: School District Office LAN and Support Systems

The School District offices should form the focal point for
interconnection of all schools in the district.  Within the District
offices, network operations can be monitored and problem
resolution managed.  One or more network servers can provide
essential network support as well as central archiving of common
information and software.

A critical role of the district office will be to manage Internet
"Domain Name System " (DNS)[13] service for the district s schools.
DNS is required of all Internet networks.  It defines the basic
network level identity of each computer, workstation, server, and
active network component.  This function is described more fully
below under Network Management and Operational Monitoring.

The district offices should be wired in a manner similar to a typical
school, as shown above.  This will allow teachers, superintendents,
and principals to communicate and share information easily.  In
addition, a NAS connected to a central pool of modems could
provide dial-in access to the district network.

Step 4: Interconnection of the School District with the Internet

Connection of the entire school district to the Internet will take
place through the district office interconnect site, as shown in
Figure 6.  This hierarchical model can be extended another level to
interconnection of the school district offices through the county
office of education facilities.  Many administrative information
resources could be located at the county level, and there might be
cost savings if the entire county connects to an Internet service

_____________________________________________________________________
[13]See RFCs 1034 and 1035 for the full explanation of DNS.

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provider through a single point.  The bandwidth required for this
single connection, however, will be much greater than that
required for each school district since traffic will be aggregated.

This hierarchical topology also provides a logical model for network
support and information resource management.  The school district
or county offices can provide continuous monitoring of the network
and provide high level technical expertise for problem resolution,
relieving the individual schools of this burden.  Interactions with
communications circuit providers and Internet service providers
will be more effective if handled through a central "trouble desk."
Similarly, it is highly desirable that network users have a single,
well known point of contact in case of problems or questions.

Internet service should be acquired from the most cost effective,
reliable Internet service provider.  Circuit services can be similar
to those shown in Table 2 above.  The higher speed services should
be considered if traffic demands increase and funding permits.
Circuit costs usually will be lowest when connecting to the

provider with the nearest "point of presence" (POP), but newer
technologies such as Frame Relay and SMDS[14]  make circuit costs
less dependent on distance.  The Internet connection will require a
high quality router that can be configured to interact correctly
with the service provider s routers.  In most  cases, this can be the
same router used to support the local school connections.

Integration of Existing School Networks

Many schools have developed LAN systems in support of particular
classroom activities or administrative functions.  In some cases the
technologies used are not those recommended for new
installations.  If these older LAN systems are capable of
transporting Internet protocols they may be integrated into a new
LAN system and replaced later as funding permits.

For example, IEEE 802.5 Token Ring is often used to interconnect
DOS PC-type computers and IBM minicomputer servers.  Token
Ring networks can transport Internet protocols and software is
available for DOS computers to support basic Internet functions.
Many Internet routers support optional Token Ring adapters.  This
is the recommended way that existing Token Ring LANs can be
integrated into a wider school LAN system in order to extend
Internet information resources to those PC users.

_____________________________________________________________________
[14]  At this time, these services are not widely available.

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Another example is a Novell Network system using ethernet as a
LAN.  The ethernet LAN, if implemented well, is perfectly capable
of transporting Internet protocols as well as Novell protocols,
simultaneously.  Each PC or Macintosh can be given software that
will allow both Novell and Internet services to be used as needed.
This coexistence is important so that, for example, a person using a
PC that depends on the Novell server for disk file space can
transfer a large file from a remote Internet server to the PC s
pseudo-disk.  It also permits each user to run client software such
as Eudora (electronic mail), Gopher (information services), and

Mosaic (World Wide Web information services) which require
direct Internet access.  To integrate the Novell ethernet LAN into
the wider school LAN system a simple ethernet repeater can be
used in a manner similar to Figure 3 above.

An alternative to supporting both protocols that is sometimes
suggested in cases such as the one cited above in which a network
server already exists is to use the server as a "network application
gateway."  This approach is strongly discouraged.  It is essential
that each computer and workstation support Internet protocol data
communication directly so that modern client/server applications
can be supported where the server or servers may be located
anywhere on the Internet.  The "gateway" approach severely
restricts the workstation s potential ability to access multimedia
and other important information resources.

Some technologies, such as "arcnet," may not be capable of
supporting Internet protocols but may offer "terminal emulation"
shared access to something like a "modem pool."  The modem
adapter might be rewired to connect to ports on a network access
server instead.  This would provide simple access to information
resources for the arcnet users.

In any case, older LAN technologies should not be expanded and
should be phased out as funding permits.  It is critical that there
be a relatively homogeneous installed base of technology in order
that new applications of information resources can be provided to
the entire school community.

Network Management and Operational Monitoring

All networks require some level of network management in order
to ensure reliable service.  Monitoring of the health of the network
can help identify problems before they become detrimental to
network users.  It also can help predict trends in traffic patterns
and volume.

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Internet technology network management consists primarily of
determining the proper routing parameters for optimal and
reliable network operation, assignment of network Internet
Protocol (IP) addresses and maintenance of a network-accessible
database of node names corresponding to each address[15], and
monitoring the daily operation of the network.  These functions
typically are performed by the staff of a Network Operations
Center (NOC).

Domain Name System

The Internet Domain Name System (DNS) is the mechanism for
documenting and distributing information about the name and
address of each computer attached to the network (network nodes).
The DNS service is provided by software that runs on the main
network server.  It uses a database that is created and maintained
by the NOC staff.

An Internet address is the numerical identifier for a node and it
must be unique among all nodes associated with the network.
Furthermore, if the network is to be part of the global Internet, all
addresses must be legitimate within the worldwide Internet
system.

Associated with each numerical address can be one or more "node
names."  Although computers have no difficulty using numerical
addresses, it is often easier for computer users to remember and
use the node names rather than the numerical addresses.  In
particular, electronic mail addresses use node names.  DNS node
names are hierarchical and by appropriately using this hierarchy
"subdomains" can be assigned to each school site or district office.
In this way, naming can be structured to be flexible as well as
meaningful in the context of the whole organization.

A plan for the assignment of IP network addresses and node names
should be developed early in the planning for the network
installation.  Initially, the database serving the DNS should reside
on the "district server" so that there is one site at which all
assignments are officially registered.  As the network grows and
expertise is developed, secondary DNS service can be run on the
servers at larger school sites.

The main DNS server for the district should be located as close to
the Internet connection (topologically) as possible.  This proximity
is to help ensure that network problems within the district
network will have minimal impact on access to the server.  This

____________________________________________________________________________
[15] See RFC 1480 for a discussion of Internet naming conventions for school
       networks.

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design is illustrated in Figure 1 where the district server is on an
ethernet connected directly to the main distribution router.

Associated with the assignment of node names and addresses
should be a database of specific information about the computers
connected to the network.  When trying to resolve problems or
answer user questions, it is very important to know where the
computers and other nodes are located, what type of computer and
software are in use, and what type of network connection is
installed.  With proper software this database can be used to
extract the DNS database discussed above.

Network Monitoring

Internet network monitoring serves three primary purposes:

1)      Constant observation of the "health" of the network, network
        components, and external network connectivity.  Standard
        Simple Network Management Protocol (SNMP) support is built-
        in to most active components today.  Even network servers and
        workstations can be monitored in this way.  Operations staff
        can be provided with network monitoring stations that will
        display alerts immediately upon detecting a wide variety of
        problems or anomalies;

2)      Collection of statistics on the performance of the network and
        patterns of traffic in order to identify needed enhancements or
        re-engineering.  Using the same SNMP capabilities mentioned
        above, data on packet forwarding and total traffic volume can
        be collected and used to generate periodic reports on network
        utilization;

3)      More rapid problem resolution.  When problems do occur,
        SNMP tools can help to pinpoint the source of the problem(s).
        Such problems include transient routing anomalies, DNS query
        failures, or even attempts at breaking into network accessible
        host computers.

        Since network management and monitoring is a technically
        demanding task and requires special equipment and software, it
        should be a centralized function in the initial design of school
        network systems, as discussed above.

Summary

The model for school network implementation described above is
based on broad experience with this technology in higher education
and administrative environments.  Many schools have already

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installed networks very similar to this model.  We believe that it is
a practical first step towards bringing a powerful resource to bear
for enriching all of the nation s school programs.

None of the suggestions above preclude or postpone in any way
future development of an integrated voice, data, and video network
for the nation s schools.  Use of existing Internet carriers does not
in any way preclude future development of a separate "backbone"
for the K-12 community if such a "backbone" is determined to be
cost effective or required for enhanced functionality.  Rather, the
infrastructure recommended above can be the foundation at the
local level in preparation for future high capacity networks.

IV.     Network Support

The installation of a campuswide network or Internet connectivity
will also require a commitment to ongoing network support and its
related resource requirements.  There are two major areas of
network support, network operations and user services.  These
support functions are usually performed through the
establishment of a Network Operations Center (NOC) and
Network Information Center (NIC), however both functions can be
performed by the same individual or groups of individuals.

Network Operations Center (NOC)

The Network Operations Center (NOC) oversees the performance
of the physical network and some of its software support systems.
The staff may install networks, configure network devices and
provide configurations for computers attached to an organization-
wide network.  Real-time monitoring of the network can be
performed using the Simple Network Management Protocol and
many vendors produce monitoring systems that graphically display
network performance, log events and usage, and produce trouble
tickets.  The use of this type of network monitoring allows NOC
staff to quickly detect problems and greatly reduces the personnel
required to perform this function.  Routine monitoring of the
network can help to anticipate problems before they develop and
lead to reconfigurations and upgrades as indicated.  If problems do
arise, NOC personnel may go on-site to troubleshoot a problem and
repair it.  If the problem is not local, NOC personnel will work with
school district, County or regional network technical staff to
resolve the problem.

NOC personnel also assign addresses to network computers and
devices and maintain the Domain Nameservice (DNS) for their
organization.  Domain Nameservice is a machine registry service
that runs on a network server and enables access to machines by

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easy to remember names, rather than a network number.  DNS is
required for any organization connected to the Internet and critical
to the establishment of an electronic mail system.

It is most cost effective to have the Network Operation Center
serve an entire organization or region.  In order to ensure timely
service all the way out to the most remote LAN, it is recommended
that an organization assign local area network administration
duties to on-site personnel to interact with NOC staff and assist
with the maintenance of the network.  In the case of a school
district, administrative support staff, teachers, librarians or school
based technical staff can each take responsibility for a LAN or
group of LANs.  If a problem arises, it can be reported to the LAN
administrator.  The LAN administrator can determine if the
problem is local or remote and if NOC staff need to be notified.  If
so, the LAN administrator acts as the single point of contact for
the NOC to provide a good communications channel for
information and ensure efficient coordination of problem
resolution.  This method of delegating responsibility provides for a
high level of service for each LAN and optimally uses the time of
NOC staff to provide economies of scale.

Network Information Center (NIC)

The Network Information Center (NIC) provides information and
support services to facilitate the use of the network.   The NIC
often provides a help-desk service to answer questions about use of
the network, references to useful resources and training in new
tools or applications.  The NIC may also provide services such as
an on-line directory of network users and their electronic mail
addresses, bulletin board services of information and notices about
the network and on-line training materials.  These NIC services
could be provided on a school district or County level.  Most of the
information would not be site specific and can be delivered
electronically using electronic mail, electronic conferencing, on-line
bulletin boards or other document delivery mechanisms.   These
types of services may be well suited for a school or school district
librarian.

Other  types of support services may be performed by NIC
personnel such as maintenance of the electronic mail system or
Postmaster duties, coordination of an on-line bulletin board or
campuswide information system (CWIS) and management of an
on-line conferencing system.  These duties are more technical in
nature and will require technical staff to maintain them.

Postmaster

Every organization which uses electronic mail should have an
Electronic Mail Postmaster and a mailbox, postmaster, for the

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receipt of messages regarding use of the electronic mail system,
mail problems and general inquiries about reaching people within
the organization.  The Postmaster is responsible for reading
postmaster mail and responding to inquiries.  These duties can be
performed by non-technical staff with forwarding of messages to
the appropriate technical support person as required.

CWIS Administrator

Campuswide information systems or bulletin boards are one of the
most useful applications on the network.  These systems allow
people to share timely notices, documents and other resources with
large groups of people.  These systems typically provide a
hierarchical or tree like structure of menus that lead to on-line
documents or other services.  Common types of information include
deadline notices, grant announcements, training schedules, lists of
available resources such as videos in a library or reference
materials.

A CWIS or bulletin board must have an administrator or sponsor
to oversee the design and maintenance of the system so that it is
easy to navigate and find information, provides a professional
presentation of information and ensures that information remains
timely and relevant.  This function can be performed by NIC staff,
or trained librarians or administrative staff as appropriate.

Management of On-line Conferences

On-line conferences provide a way for groups of people to share
information, discuss ideas and pose questions.  Conferences
usually are set up to serve the needs of a group of people sharing a
common interest.  For example, an on-line conference might be
established for teachers to discuss a new science teaching
framework or a teacher may establish a conference for the
discussion of the Civil War as part of an American History class.
Some conferences are on-going and may exist for years.  Others are
short term and may exist for only one semester.  Conferences may
be created using the electronic mail system or a facility called
Usenet News.

On-line conferencing systems require a server computer on the
network that collects messages posted to a conference and
distributes them when requested.  Usually these systems are
managed by a systems administrator and someone must configure
the system to establish and delete groups upon request.  Other
management duties include scheduling the deletion of old
messages and archiving especially valuable conversations.
Typically these duties are performed by a systems administrator or
technical staff.

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Staffing Considerations

The duties described above do not necessarily require hiring new
staff and they may be shared by people already within an
organization.   Small schools or districts may rely on County Office
of Education Information Systems staff to perform all functions.
Larger schools or districts may have staff to take on any
combination of duties and rely on the County Office of Education
for others.   Access to the network and the use of electronic
communications allows people throughout the organization to
perform these functions remotely.  The assignment of
responsibility for any of these duties is flexible and should be
approached with the goal of providing the highest quality of service
in the most cost effective and workable manner.

VI.     References

Estrada, Susan, "Connecting to the Internet", O Reilly &
Associates, Inc. (ISBN 1-56592-061-9) lists Internet service
providers in California and the nation.

Honey, Margaret, Henriquez, Andres, "Telecommunications and K-
12 Educators:  Findings from a National Survey," Bank
Street College of Education, New York, NY, 1993.

Department of Education, State of California, "The K-12 Network
Technology Planning Guide," 1994.

Department of General Services, State of California, "Virtual
Schoolhouse - A Report to the Legislature on Distribution
Infrastructures for Advanced Technologies in the
Construction of New Schools, K through 12," Feb 1993.

EIA/TIA-568 "Commercial Building Telecommunications Wiring
Standard."

VII.    Authors Addresses

        Joan C. Gargano
        Information Technology
        Distributed Computing Analysis and Support
        University of California
        Davis, CA   95616
        jcgargano@ucdavis.edu

        David L. Wasley
        Data Communication & Network Services
        Information Systems and Technology
        University of California
        Berkeley, CA   94720
        dlw@berkeley.edu

Gargano, Wasley                [Page 20]

------------------------------

Date:    Sun, 27 Feb 1994 08:10:46 CST
From:    William Manning <bmanning@IS.RICE.EDU>
Subject: Info

>From last year....

Announcing the July Edition of "The Incomplete Guide to the Internet and
Other Telecommunications Opportunities Especially for Teachers and
Students, K-12". This document is a resource guide and how to manual for
beginner and intermediate users of the Internet, as well as an excellent
reference for advanced users.
To ftp the Guide, go to zaphod.ncsa.uiuc.edu or ftp.ncsa.uiuc.edu and look
in the education directory. In there is a directory called
Education_Resources. In there you will find a directory (Incomplete_Guide)
that contains several different formats of the Guide and a README file.
Please note that most of the different formats are about 1.5 Megabytes.

If you do not wish to ftp the Guide, you can contact the Education Group at
NCSA to have a hard copy sent to you. There is a charge for this which will
cover the cost of materials and shipping. The guide is approximately 300
pages.

You can contact us at:
Chuck Farmer
NCSA Education Group
605 E. Springfield Ave.
Champaign, IL 61820
cfarmer@landrew.ncsa.uiuc.edu

--
bill manning
third assistant vice-president
schenectady consolidated nail-file & eyebrow tweezer corporation
"Adult signature required"  - UPS

------------------------------

Date:    Sun, 27 Feb 1994 13:36:53 -0800
From:    Jeffrey d Miller <jemille@EIS.CALSTATE.EDU>
Subject: Re: research on computers in early childhood education

We too are interested in research on Computers in ECE.  We are developing
a short survey/questionaire and will post to this list.  Any ideas for
inclusion on the survey will be appreciated and those responding will get
a copy of our results.  We will asking k-3 teachers in the public schools
and anyone else out there that wants to respond.  Any ideas and uses of
computers in ECE will also be welcomed.
More on this later.

Jeffrey Miller                          jemille@eis.calstate.edu
1737 Oxford                             Solana Highlands School
Cardiff-By-The-Sea, CA 92007            Solana Beach School District
33 Degrees 1 Minute 18 Seconds North    Pacific Oaks College Ed Tech
117 Degrees 16 Minutes 49 Seconds West
                                        When in doubt; frolic!

------------------------------

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