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Introduction and Background Information Network Assessment Audit Problem Definition Requirement Specifications and Scope of Work

Network Assessment — Springfield R-XII

Introduction and Background Information

Springfield R-XII School District is located in Greene County in southwestern Missouri; approximately 169 miles south of Kansas City and 218 miles southwest of St. Louis. This district is comprised of 39 elementary schools, nine middle schools and five high schools. Total enrollment for the 1999-2000 school year was 24,884. Total certified staff for the district is 1,869.

The technical staff consists of one technical coordinator, one network technician and a system administrator. The technical staff is responsible for network maintenance, system implementation and administration.

Ninety percent of the schools in the district are homed into the Kraft Administration Building via 64 Kbps or 128 Kbps ISDN connections. Six schools that are homed via Synchronous Optical NETwork ring (SONET ring). The city of Springfield is responsible for maintaining the SONET ring. The bandwidth assigned to the six schools is 1.544 Mbps. The internal wiring for each campus is 10BaseT. Each site visited had Windows 95 or Windows 98 for workstations, and one site had a Novell 3.12 server. The computing labs for each school consisted of 25-30 workstations, with an anticipated growth to approximately 50 or more workstations within the next year or so.

The entire district's topology was learned via Routing Information Protocol version 2. Each campus LAN comprises 100 Mbps switched Ethernet for the backbone and 10/100 Mbps-backbone access via hubs. Each campus also includes terminal servers for asynchronous access to the DEC Alpha administrative servers in the Kraft Administration Building.

The technical direction for the district is to move to Microsoft Windows NT Domain architecture as well as to the Microsoft Exchange Mail Transport System. Access links for each site will be upgraded pending the availability of E-rate funding.

Network Assessment Audit

Figure 1. Springfield R-XII Network Diagram

After visiting four sites, it was confirmed that the actual network infrastructure matched the diagram from the preliminary data gathering. The four sites visited were: Kraft Administration Building, Weller Elementary School, Carver Middle School and Hillcrest High School. Each site exhibited the diverse connections that can be found throughout the district. The high school is connected via SONET, the middle school via 128 Kbps ISDN and the elementary school via 64 Kbps ISDN. The administrative building is the central homing point for all connections.

At the administration building there are two Bay Networks ASN routers connected to two Primary Rate Interface (PRI) ISDN connections. These connections are provided by Southwestern Bell Telephone. Each remote site is connected via Southwestern Bell's ISDN switch to the PRIs into the administration building. The routers are connected to a Bay Networks 100 Mbps Ethernet switch. This switch serves as the backbone for the administrative building and all remote campuses that need to access the Internet. The Watchguard firewall separates the networks into external and internal as well as providing Network Address Translation (NAT) services. The ISDN WAN is privately addressed using the 192.168 network. Currently, the district has assigned to them 204.184.214.0/24, and 207.160.188.0/24.

There are three Digital Equipment Corporation Alpha servers at the administration building. These machines provide student registration, and currently, e-mail services. The terminal servers are sporadic throughout the district. These provide legacy asynchronous access services to the DEC Alpha servers. The dumb terminal access methods are still used throughout the district. Some terminal servers have been discontinued in their use, but still remain on the network.

At each site, there is an Ethernet switch serving as the backbone for the campus LAN and hubs at each lab location within the campus. The majority of these hubs and switches are 3Com Corebuilders and small 24-port Super Stack hubs. The infrastructure at each site was Category 5 STP wiring. None of the sites exhibited any degradation in cable integrity. Bay Networks ARN routers were installed at each remote site. Each router included an ISDN module capable of 64 Kbps or 128 Kbps BRI access. The routers are running Routing Information Protocol version 2 to learn the network topology. Sites that were connected via SONET had T1 modules installed in their routers. The MOREnet router was a Bay Networks ASN router, but was replaced with a Cisco 2500 series router as well as a Kentrox Servicepoint SDU.

Problem Definition

During the preliminary data gathering process, the site did not make us aware of any problems with their network. MOREnet was not given any preliminary problem reports nor were there any prevalent incidents reported in the Remedy system.

The site was already aware of their current problems with 64 Kbps and 128 Kbps access links being saturated at peak traffic periods. They indicated that they are in the process of upgrading these links once adequate funding had been provided through the E-rate program. This process is still pending.

Problems that were revealed during the question and answer period pertained to the technical direction of the district. The district, as of MOREnet's visit, was in the bidding process for Microsoft Exchange mail transport system. Included in the bid was a transition to the Windows NT network operating system. The primary reasons for the transition to Windows NT domains were administration and access control to network elements. The primary reasons for the Exchange mail system were for the calendar support and support for rich-text format e-mail. Currently the e-mail system is done via text-base UNIX command line logins on the DEC Alpha servers. The problems and discussions that MOREnet engaged in with the site contacts pertained mostly to their deployment of the new e-mail system and the ramifications of doing so.

MOREnet's recommendations to the site were purely objective in nature. The pros and cons were given for the technical direction. Since NT and Exchange are very bandwidth hungry, their links could be taxed even further than they are being taxed today. The site informed MOREnet that they would deploy a server in each location to keep the traffic local and off the saturated links. After the question and answer period, MOREnet offered the following advisories:

• Administrative overhead would increase for each deployed server.
• Support costs would increase for each deployed server.
• Link traffic would increase due to the server-based architecture of Exchange.
• Link traffic would increase due to the NT domain architecture and nature of NetBIOS.
• Performance characteristics of large-scale deployments of NT and Exchange historically have been poor at best.

The site will review these issues with their technical coordinator, and possibly examine them in depth before making any final decisions on the technical directions.

The site contacts told MOREnet that they were experiencing a problem with slowness at Carver Middle School. They said it was indicated by slow PING response times and consistent complaints from personnel at the school.

Requirement Specifications and Scope of Work

As indicated before, the site was already aware of the problems associated with their current access links. The concerns of the site primarily lie with the deployment of NT and Exchange, as well as for current interim relief of their saturated links.

The scope of MOREnet's visit was to give an objective consultation about the district's concerns, including the technical direction and current problems the district is experiencing with their network.

After lengthy discussion, MOREnet presented a simple mail server system design to the site. The site seemed interested and wanted more input and information on how this design could be implemented. The diagram below is a rough version of the design recommendations presented.

Figure 2. Springfield public schools mail server design with calendar support

The recommended mail system architecture presented to the site consisted of two mail exchangers whose sole responsibility was mail transport to and from the main mail server and SMTP capable clients. The main mail server is responsible for holding mail and for Post Office Protocol (POP) transactions. An SQL server is provided for calendar support and user administration support. The SQL server can talk with the DNS servers to create mail aliases with which to send mail. The specifics of the system were not discussed.

These servers were to run some variant of UNIX and the SQL server would run MySQL. The main mail server would run a POP server such as qmail or University of Washington POP3 daemon. The mail exchangers would run a variant of UNIX and sendmail as the mail server.

MOREnet advised the site that there probably would be a considerable learning curve in these implementations; however, there is an abundance of support documents on the Internet. Configurations such as this have been known to support 50k+ user accounts without any degradation in performance. The flexibility of the operating system itself would allow the administrators to add and delete users easily, even during scheduled changes (i.e. graduation of students).

The benefits of this configuration are:

• Scalability
• Performance
• Cost (everything is free)
• Flexibility

The possible caveats:

• Learning curve

The site wanted MOREnet to look at Carver Middle school, and look into the problem of slowness to the site. After doing some PING tests to different network devices along the path from the site to the Kraft Administration Building, it was determined that the link between the site and the Kraft Building was bouncing. MOREnet recommended that the site contact Southwestern Bell for appropriate circuit testing.

MOREnet recommended some solutions for interim relief of the saturated links. These solutions were:

• Web caching appliances
• Changing from RIPv2 to static routing
• Payload compression on routers

MOREnet stressed that these solutions would reduce traffic on the links and free up bandwidth for critical applications. Changing routing protocols would relieve unnecessary broadcasts. While visiting the site, data analysis of the links showed significant RIP traffic. Payload compression would decrease packet sizes while allowing more traffic to be transmitted across the links. However this solution could increase router overhead and decrease overall router performance.

The future technical direction for Springfield public schools is dependent upon E-rate funds and a close look at what will and will not work for a district of this size. The site indicated that they wanted to provide e-mail accounts to every student. This totals almost 25,000 student e-mail accounts and almost 2,000 staff e-mail accounts for a grand total of almost 28,000 accounts for the district. Careful consideration is needed in deploying certain technologies and turnkey solutions. The solutions outlined here are mostly interim due to the dependence on E-rate funds.

In conclusion, the site was very appreciative of MOREnet's consultative efforts, while MOREnet learned more in-depth information about the needs of the Springfield district as well as a broad scope of the needs of districts all over Missouri.