## (1) WAN Requirements Document

Note: below is the same as the LAN requirements documentation, execept I have highlighted only those sections relevant to our WAN design.

### 1. Overview: District WAN and LAN

- Implement a LAN for local school
- Requirements:
  - (US) $200,000 budget for each school
  - > 7-10 years functionality
  - > 100 times growth
  - > 1 Mbps to every host computer
  - > 100 Mbps to every host server
  - must satisfy TIA/EIA-568-A standards

### 2. School District WAN Specs

- District schools connect to each other & to Internet via WAN
- Requirements:
  - 3 (interconnected) regional Hubs form the core:
    - District Office Center (single point for all Internet connectivity)
    - Service Center
    - Shaw Butte Elementary School (also includes a community school)
  - each connects to 11 schools
  - Protocols: TCP/IP & Novell IPX

###
3. School District LAN Specs

There will be 2-segments in each school & also the District Office

- Transport Speeds:
  - 10Base-T
  - 100Base-T
  - 100Base-FX
- Media:
  - Horizontal cable = 100Mbps CAT5 UTP
  - Backbone cable = multimode fibre-optic
- LAN Infrastructure:
  - based on Ethernet LAN switching
- MDF:
  - central point for LAN cabling attachment
- POP for WAN connection
  - Houses major electrical components
- IDF's:
  - used where horizontal cable > 100m or where site conditions dictate
  - connect to MDF in star or extended star topology
- Each Room:
  - has own POP with lockable cabinet for: electrical components & cable terminations
  - supplied with 4 CAT 5 UTP runs (via decorative wire molding)
    - 1 terminates at teacher's (admin) workstation
    - each is tested for 100Mbps capacity
  - supports 24 workstations

### 4. Servers

- All file servers are categorized as: enterprise or workgroup
  - enterprise - attaches to MDF
  - workgroup - may attach to IDF

Each school will have its own:

- Domain Name Servers (DNSs) & Email Delivery Server:
  - maintain complete directory of all staff & students
  - e-mail server - acts as local post office box & stores all e-mail messages
  - (enterprise)
- Administrative Servers:
  - houses student tracking, attendance, grading & other admin functions
  - available to administration only
  - (workgroup)
- Library Server(s):
  - automated library information & retrieval system - available to entire school
  - will house online library
  - (enterprise)
- Application Servers:
  - houses common user applications (including MS office applications)
  - provides for efficient upgrading of applications
  - (enterprise)
- Other Servers:
  - will all be considered departmental
  - placed according to needs
  - (workgroup)

### 5. Addressing and Network Management

- At the District Office, a master network management host will:
  - administer complete TCP/IP addressing & naming convention
  - have management rights over all devices
  - store all router configurations
- admin computers will have static addressing
- curriculum computers will use DHCP
- each regional location will:
  - house a regional network management host to support its area
  - use SNMP standards

### 6. Security

Each school has:

- 3 logical classifications (with secure interconnections):
  - Admin
  - Curriculum
  - External
- 2 physically separate LANs (admin & curriculum)
  - ACL's (on routers) will prevent curriculum accessing admin
  - Admin will be able to access curriculum *
  - e-mail & DNS will pass feely between all LANs
  - each LAN segment will have a file server
- strict user ID & password policy

### 7. Internet interconnectivity

- Internet interconnectivity (from all computers) will be:
  - supplied though District Office (a single point of contact)
  - available from all schools
  - via double firewall implementation
    - ACL's will prevent connectivity from the outside Internet

- A public backbone will be used for Internet exposed services including:
  - e-mail & DNS - which will pass freely in both directions (they pose no risk)
  - a Web server - will allow all schools to upload a home page
  - any other additional web servers

### 8. User Counts

- For each school assume:
  - max 250 curriculum computers
  - max 75 admin computers
  - each location must accommodate up to 25 computers and include:
    - 1 run for a single teacher/admin computer
    - 3 runs for student/curriculum computer

### 9. WAN - Media Capacity (not specified in origional)

- Each school is connected (using PPP) via a single T1 (1.54 Mbps) cable to the core network.
- The 3 regional Hubs will be interconnected with 4 T1s between each.
- Any additional links within the regional Hubs should be gigabit connections
- The connection from the Data Center to the Internet (using Frame Relay) has not been specified.
  - This is beyond the course, but this outwards Internet connectivity should be provided by at least 6 (perhaps 8) T1 lines

### 10. WAN - Expected Traffic Throughput (not specified in origional)

- Throughput is only as good as the weakest link.
- The best throughput for Internet connectivity an individual school could hope for is 1.54 Mbps, however a realistic estimate would involve analysing traffic patterns.
- Ideally, baseline measurements, traffic patterns and throughput are measurements you want to test and monitor rather than guess.
- The best idea would be look at existing schools (similar to the ones in our WAN) which have Internet connectivity or belong to a larger WAN.
- Only so many student computers would use the Internet at any one time during the school day (say, an average of 10% at a time & a maximum of 40% at once during school hours) - and all would be contending for 1.54 Mbps connection speed.
  - (Imaginary) worst case senario:
    - Lets say Acasia has 250 student and 75 admin computers
    - 40% of student computers (100 computers) and 60% of admin computers (45) are connected to the Internet
    - 1.54 Mbps shared between 145 computers equals 10.6 Kbps per computer.
    - and in reality the actual thoughput for each individual would much less than this (due to contention, collisions etc.)
  - For comparions, your average dial-up rate connect (about 46 Kbps in Australia and probably similar in America) is over four times this fast.
    - At peak times, students will be quite disappointed in their connection speed.
    - If the budget was permitting it might be worth replacing the T1 with T3 (or else installing a second T1)
- 11 schools connect to each of the regional Hubs, and since these regional Hubs are interconnected by 4 T1s, if all 11 schools are "maxed out" with students surfing web pages/checking e-mail at the same time of the day, the limiting factor (the slowest link) might be these 4 T1s!
  - (Imaginary) worst case senario:
    - (4 * 1.54 Mbps) / (11 schools * 145 individuals online) = 3.9 Kbps per computer
  - Fortunately it's unlikely all schools will be "maxed out" at the same time.
- Go to the bottom of section "(3) Logical Topology" (in the menu bar) to better understand how internet connectivity will work and where contention will occur.