The Threaded Case Study

Overview of Threaded Case Study (TCS):

(Notes, suggestions and information related to the case study for each semester will be referenced in this section.) The TCS is a performance assessment that will be introduced in the first semester although the actual project work will not be done until semesters 3 and 4. As concepts are introduced, students will learn to apply them. The Engineering Journal and the Study Guide will contain content, concepts, and understandings from the first two semesters that will assist in building the prerequisite knowledge for the TCS. A large school district in Phoenix, Arizona will be the field model that is included in the TCS. Each team of students will be given architectural drawings (electronically) of the various schools along with the actual wiring drawings (electronic format.) The completed design considerations and specifications document will be included as a teacher resource. Each student will keep an Engineering Journal and a Study Guide during the four-semester course. Teams of students will submit a final design document and make an oral presentation of their project near the end of semester 4. Criteria for the project will be a series of rubrics that are linked to National Standards in the areas of Science, Mathematics, Reading, Writing, and SCANS. Technology Implementation Requirements General Requirements The school district is in the process of implementing a enterprise wide network which will include Local Area Networks (LANs) at each site and a Wide Area Network (WAN) to provide data connnectivity between all school sites. Access to the "Internet" from any site in the school district is also an integral part of this implementation. Once the network is in place the school district will implement a series of servers to facilitate online automation of all of the districts administrative and many of the curricular functions. Since this network implementation will have to continue to be functional for a minimum of 7-10 years all design considerations should include 1000% growth in the LAN's and 100% growth in the WAN. The minimum requirement for initial implementation design will be 1.0 Mega Bits per second to any host computer in the network and 100 Mega Bits per second to any server host in the network. Only two OSI layer 3&4 protocols will be allowd to be implemented in this network, they are TCP/IP and Novel's IPX. TABLE OF CONTENTS SECTION 1 - Wide Area Network SECTION 2 - Local Area Network & Wiring Scheme SECTION 3 - District Supplied Servers and Functions SECTION 4 - Address and Network Management SECTION 5 - Security SECTION 6 - Internet Connectivity SECTION 1 - WIDE AREA NETWORK The Washington School District Wide Area Network (WAN) will connect all school and administrative offices with the district office for the purpose of delivering data. The WAN will be based on a two layer hierarchical model. Three (3) regional Hubs will be established at the District Office, Service Center and Shaw Butte Elementary School for the purpose of forming a fast WAN core network. School locations will be connect into the WAN core hub locations based on proximity to hub. TCP/IP and Novel IPX will be the only networking protocols that will be acceptable to traverse the district WAN. All other protocols will be filtered at the individual school sites using Routers. Routers will also be installed at each WAN core location. Access to the "Internet" or any other outside network connections will be provided through the District Office through a frame relay WAN link. For security purposes, no other connections will be permitted. SECTION 2 - LOCAL AREA NETWORK & WIRING SCHEME Two Local Area Networks (LAN) segments will be implemented in each school and the District office. The transport speeds will be Ethernet 10BaseT, 100BaseT and 100baseFx. Horizontal cabling shall be Category 5 Unshielded Twisted Pair (CAT5 UTP) and will have the capacity to accommodate 100 mbps . Vertical (Backbone) cabling shall be CAT5 UTP or fiberoptic multimode cable. The cabling infrastructure shall comply with EIA/TIA 568 standards. One LAN will be designated for student / curriculum usage and the other will be designated for administration usage (see: SECURITY SECTION). The LAN infrastructure will be based on ethernet LAN switching which will allow for a migration to faster speeds (more bandwidth) to the individual computers and between MDF's and IDF's without revamping the physical wiring scheme to accomodate future applications. In each location a Main Distribution Facility (MDF) room will be established as the central point to which all LAN cabling will be terminated and will also be the point of presence for the Wide Area Network connection. All major electronic components for the network, such as the routers and LAN switches will be housed in this location. In some cases an Intermediate Distribution Facility (IDF) room will be established, where horizontal cabling lengths exceed EIA/TIA recommended distances or where site conditions dictate. In such cases, the IDF will service its geographical area and the IDF will be connected directly to the MDF in a STAR or EXTENDED STAR topology. Each room requiring connection to network will be able to support 24 workstations and be supplied with four (4) CAT 5 UTP runs for data, with one run terminated at the teachers workstation. These cable runs will be terminated in the closest MDF or IDF. All CAT 5 UTP cable run will be tested end-to-end for 100 mbps bandwidth capacity. A single location in each room will be designated as the wiring point of presence (POP) for that room. It will consist of a lockable cabinet containing all cable terminations and electronic components; i.e. data hubs. From this location data services will be distributed within the room via decorative wire molding. Network 1 will be allocated for general curriculum usage and network 2 will allocated for administrative usage. SECTION 3 - DISTRICT SUPPIED SERVERS AND FUNCTIONS All file servers will be catagoized as Enterprise or Workgroup type services then place on the network topology according to function and anticipated traffic patterns of users. DOMAIN NAMES SERVICE and EMAIL SERVICES Domain Name Services (DNS) and E-Mail delivery will be implemented in a hierarchical fashion with all services located on the master server at the district office. Each Hub location will contain a DNS server to support the individual schools serviced out of that location. Each school will also contain a host for DNS and E-mail services (local post office) that will maintain a complete directory of all staff personnel and student population for that location. The school host will be the local post office box and will store all E-mail messages. The update DNS process will flow from the individual school server to the Hub server and to the district server. All regional servers will have the capability to communicate between themselves thus building redundancy in the system in the event that the District master server is unavailable. Should the District master server require a partial or complete restore of data, the ability to query any or all of the regional servers to aquire the needed information will be provided. ADMINISTRATIVE SERVER The school district is moving towards a totally automated server based administration system.Each school location will contain an Administration server which will house the student tracking, attendance, grading and other administration functions. This server will be running TCP/IP as its OSI layer 3&4 protocols and will only be made avalible to teachers and staff. LIBRARY SERVER The school district is implementing an automated library information and retrieval system which will house an online library for curricular reseach purposes. This server will be running TCP/IP as its OSI layer 3&4 protocols and will made available to anyone at the school site. APPLICATION SERVER All computer applications will be housed in a cenrtal server at each school location. As applications such as Word processing, Excel, PowerPoint , etc are requested by users these applications will be retrieved from the application server. This will provide district support staff with a easy and efficient method for upgrading applications without having to reload new software on each computer in the district network. This server will use TCP/IP as its OSI layer 3&4 protocols and will be made available to anyone at the school site. OTHER SERVERS Any other servers implemented at the school sites will be considered departmental (workgroup) servers and will be placed according to user group access needs. Prior to implementation of other servers a requirements analysis must be submitted for the purpose of determining placement of the server on the district network. SECTION 4 - ADDRESSING AND NETWORK MANAGEMENT A complete TCP/IP addressing and naming convention scheme for all host, servers and network interconnect devices will be developed and administered by the District Office. The implementation of unauthorized addresses will be prohibited. All computers located on the administrative networks will have static address, curriculum computers will obtain addresses by utilizing Dynamic Host Configuration Protocol (DHCP). A master network management host will be established at the District Office and will have total management rights over all devices in the network. This host will also serve as the router configuration host and maintain the current configurations of all routers in the network. Each region location will house a regional network management host to support its area. The management scheme for the data portion of the network will be based on the Simple Network Management Protocol (SNMP) standards. All routers will be pointed to the master Network Management host for the purpose of downloading new or existing configurations. The District Office will maintain the super user passwords for all network devices and configuration changes on these devices will be authorized from the District Office: i.e. Routers and Lan Switches. SECTION 5 - SECURITY External Threats - Internet Connectivity shall utilize a double firewall implementation with all Internet exposed applications residing on a public backbone network. In this implementation all connections initiated from the Internet into the schools private network will be refused. In the district security model the network will be divided into three (3) logical network classifications, Administrative, curriculum and external with secured interconnections between them. This model will dictate that two physical LAN infrastructures be installed at all schools and the District Office, with one designated administrative and the other curriculum. Every computer and file server will be categorized according to its function and placed on the appropriate LAN segment At the schools each LAN segment will have a file server. All applications will be categorized and placed on the appropriate server. By utilizing Access Control Lists (ACL'S) on the routers, all traffic from the curriculum LANs will be prohibited on the administration LAN. Exceptions to this ACL can be made on an individual basis. Applications such as E-Mail and Directory services will be allowed to pass freely since they pose no risk. A user ID and Password Policy will be published and strictly enforced on all computers attached to the administration LAN. All computers in the District network will have full access to the Internet. All ACLs will be controlled at the district office and exceptions to the ACLs will be reviewed prior to implementation. SECTION 6 - INTERNET CONNECTIVITY All Internet connectivity will be supplied through the District Office with the District Office being the single point of contact for all schools and organizations within the district. This connection will be highly controlled and capacity (bandwidth) upgraded as usage dictates. e Internet connection will utilize double firewall implementation with a public network (ethernet backbone) established for services that will be exposed to the Internet such as master E-mail, Domain Name Services (DNS) and a World Wide Web server. All connectivity that is initiated from the Internet to the internal District network will be protected via Access Control Lists (ACLs) on the routers that make up the double firewall architecture. Any connectivity initiated from the District to the Internet will be permitted to communicate freely. E-mail and DNS services will communicate freely in both directions since these applications poses no security threat. A Web server will be located on the public backbone and partitioned to allow any school to install a Web home page on the Internet. Individual Web servers that need total exposure to the Internet will not be permitted on the internal istrict network. If schools require an independent web server host, this host will be placed on the public network backbone.

Preface:

During the Semesters 3 & 4 Academy class held in Phoenix, Arizona June 8 - 12, 1998, the participants suggested many ideas for activities that could be used so that students could demonstrate their understanding of the major concepts. These ideas were summarized and listed for each chapter to help those teachers who will be teaching Semesters 3 & 4 prior to the release of the Teacher Resource Guide this fall. If any of you who are or will be teaching these semesters have ideas you would like to suggest, please forward them to George Ward.

Local Area Network (LAN) In this chapter the students begin the design phase of the Threaded Case Study (TCS) with the design of the LAN for their assigned school. Suggested Student Activities:
• · Business Case Study - As a preliminary activity to practice some of the skills needed for the TCS, students will select a local business and write a business scenario describing the type of business and providing enough information so that 5-10 questions can be designed for the purpose of identifying the client's networking needs. Questions will elicit the hardware and networking the client currently has in place, what they anticipate getting and what network traffic is like. Students will interview the company decision-makers (such as the CEO) as well as the technology support staff. After completing the interview, the students will write a 1-2-page proposal to the company describing why the company should invest in their proposed networking scheme. This task will also require students to use mathematics and language arts skills to gather and analyze data and interview clients.
• Diagram on butcher paper -The students will be in six groups. The first three groups will verbally present segmentation concepts for bridges, switches and routers. The other three groups will do an analysis and present benefits of segmentation using each of the three concepts. Each student will write a 5 or 6 sentence paragraph comparing and contrasting each method.
• Developing and analyzing scenarios - Small groups of students write a scenario of a company with networking problems, solutions and justification for solving the problems. The groups will exchange scenarios and validate the other group's ideas and solution.
• Diagram Encapsulation - Pairs of students will diagram the five(5) conversion steps of data encapsulation and compare and contrast each encapsulation step with the OSI model. Two or three pairs will discuss their diagrams with each other.
• Wiring Closet - Small groups of students will design a single wiring closet. If possible, conduct field trips to see more examples of wiring closets and to evaluate their design. The students should design an evaluation checklist to use during the field trips. They will document what they have seen and write a summary critique based on the checklist. The students will compare critiques.

TCS: IGRP In this chapter the students apply the concepts of routing and the IGRP routing protocol to their school network implementation and demonstrate their understanding of the difference between static and dynamic routing. Suggested Student Activities:
• Develop an analogy -The students will develop an analogy to illustrate the difference between static and dynamic routing. You may wish to provide one of the following example prior to assigning the task.
  • Static routing - A traffic cop is directing traffic into a parking lot. The individual parking spaces have been numbered. The cop has no information regarding changing conditions in any of the lots. Examples of changing conditions might be a car is stalled blocking the roadway, maintenance workers repairing roadway, accident blocking the roadway. Each vehicle has been assigned a ticket with the lot number and corresponding parking space. Routing is taking place based upon the information on this ticket. All cars must enter the parking lot though the single entrance and no other route is available regardless of the changing conditions.
  • Dynamic routing - The cop is periodically receiving information regarding the status of conditions in the lot. A messenger traveling through the lots on a cart provides this information. The messenger periodically provides update information to the cop regarding modified conditions in the lots. Information is also available regarding best distances (metrics) to an appropriate lot for rerouted vehicles.
• Skit -This information could be demonstrated through a skit and discussed to ascertain if everyone understands the comparison.
• Demonstration - Routing students through different doors, or positioning students in specific seats could introduce demonstration.
• Other ideas - could be incorporating a model, written assignment, matrix or debate to demonstrate understanding of the difference between static and dynamic routing.
• · Demonstration - Routing protocols could be demonstrated by putting a message in envelope and placing an ID number on it. Each students would have an ID number and the numbers would be entered in a "routing table'. The envelope would be moved around the room using the routing table to get the person with the indicated ID number.

TCS: Access Control Lists Students will reinforce the methods for controlling the flow of data packets based on layers 2 and 3 addressing and layer 4 services. Suggested Student Activities:
• Analogy - Continue the analogy used in Chapter 5.
• Written Explanation - Students will write an explanation of how routers forward packets; base of information contained in layers 3 &4 and headers of the packet. This could be done individually or in a small group. Each group would then exchange the explanations to further their understanding.
• Access List - Based on the information in step above, students will write an explanation of how routers can stop the forwarding of data packets based on layers 3 & 4 and header information. Create a standard access list and describe where the access list would be applied. Set problems such as how to decrease traffic flow. After presenting and discussing the access list, have students, in small groups create an extended access list with identifications and written syntax.

TCS: Novell/IPX Protocol Students will investigate how Novel's IPX protocol behaves on their assigned school's network. Suggested Student Activities:
• Explanation- Students will write an explanation of how Novell's addressing scheme is similar and different from the IP addressing scheme.
• Poster - In partners, students will develop a logical Novell network numbering scheme that makes sense, display it on a small poster board and share it with other partner groups. All of the posters could be posted for all to see and discuss in order to clarify the understanding.
• Worksheet - Each student can practice transforming decimal numbers into hexadecimal numbers in their Engineering Journal.
• Chart - Small groups of students can list the pros and cons of the Novell IPX protocol on a chart. Charts can be shared with and explained to another small group.
• Analogy - Each student will write an analogy (possibly using advertisements) to show how SAP works.
• Chart - Small groups of students will create a chart that demonstrates the transformation from Binary to Decimal to HEX. Students will explain their chart with other groups or give a brief explanation to the whole class.
• Questions - Divide the class into small groups of three or four students. Each group will determine and explain how the Network Traffic Patterns differ after implementing IPX.

TCS: Wide Area Networking (WAN) Students will focus on interconnecting all school sites into WAN topology that will meet the needs of the user's requirements. Suggested Student Activities:
• Survey - Students will individually write 3 or 4 questions to be used to determine what telephone services are needed for a particular school. In small groups the questions will be shared and the most important questions will be developed into a survey. The surveys can be shared from each group to determine a class survey that can be mailed or faxed to various telephone providers to gain needed information in making decisions about matching the user's needs and networking possibilities.
• Written Paragraph - Small groups of students will select WAN services for their school. Using survey questions, students will research services offered in their area and tour the local WAN service provider, determine costs and range of services and make necessary contacts to determine the best selection of services for that school. Each student will write a paragraph telling what services were selected and why.
• Software - If available, use the "What's up" software to analyze the through put and different speeds.
• Written Explanation - Place fifteen different servers on a network map and have groups of students determine if they are placed correctly. Students will give a written explanation and rationale as to where servers should go. This should be determined by traffic patterns of users.

TCS: PPP Suggested Student Activities:
• Diagram - In small groups, students will draw a diagram showing subprotocols- NCP, LCP. More reference material is contained in RFC on the web for PPP.
• Paragraph- Students will write a paragraph describing the advantages of PPP over other WAN protocols.
• Paragraph- Students will write a paragraph describing the advantages of PPP over other WAN protocols.

TCS: ISDN Suggested Student Activities:
• Poster - Have groups of students make a poster that describes what each component is and simulates the three channels. Students will label devices where they sit, and label the layer, what it connects to, and the connection points.
• Game - Pairs of students will write PAP or CHAP numbers on 5 3x5 cards. Play a mathematical game to illustrate the difference between PAP and CHAP. Exchange the flash cards and have students calculate the location.
• Searching the Internet - Have students go onto the Internet and retrieve some specific information or specifications for ISDN. Each student will record the path their request took in their Engineering Journal.
• Role-Play Interview - Divide the class into two groups. One group is the school and the other group is the networking company. The networking company group will develop questions to use for determining needs for setup of ISDN. The school groups would develop a checklist to analyze their needs. After using the questions to role-play an interview with the school groups, the networking groups will develop and present a proposal. The school group will analyze the proposal based on their checklist.
• Design Questions - Find someone who is an expert to speak to the class (such as an ISDN installer.) In small groups, students will prepare questions to ask the speaker. Have the speaker provide information and discuss what is required. The students will use their questions during the visit.

TCS: Frame Relay This chapter builds the conceptual understanding of what you accomplish with frame relay. Suggested Student Activities:
• Analogy - Use the analogy of getting water to a community to explain how frame relay works. Discuss questions such as the following: How is an adequate amount of water maintained for each home and business? Talk through the water system analogy (pipe, storage tank, valves, pipes to community, add-ons for new homes, etc.). You may wish to list the key elements on a chart or board. Compare the analogy to the process of frame relay. You may place the processes of a frame relay next to the corresponding water distribution process.
• Analogy -The telephone system would be another system to compare to frame relay. If either analogy is used, develop steps for a Frame Relay and compare each step with the analogy used. How closely does it match? Where does it differ? You may do the water analogy as an example and have students follow the same process with the telephone system. Students may write their analogies and have them posted on a chart so that all students can help clarify their understanding.
• Discussion Opener - The concept could be introduced by discussing the function of hallways and exits in a school or sports stadium.