The document outlines recommendations for upgrading the network of software company ADTECH, which has sites in Auckland, Wellington, and Christchurch. It recommends establishing a star topology for LANs using category 6 cabling, with a switched distribution layer and routed core layer for the backbone. A bus topology using leased fiber-optic would connect the three sites. The wireless LAN at Wellington would use 802.11ac with WPA2-AES Enterprise security. Subnets would be separated by floor at each site to reduce traffic. Ethernet services and OSPF routing protocols are also recommended.

1. Data Communications &
Networks
COMP.6104
Case Study Presentation
Brad Boyce

2. Topics Covered
 Introduction
 Topology
 Connection Media
 Subnets
 Transport/Network/Routing Protocols
 Backbone Technology
 Wireless LAN Security
 Network Diagram
 Final Recommendation

3. Introduction
I have been hired to oversee the network upgrade for ADTECH, a software
development company with sites based in Auckland, Wellington and Christchurch.
Objectives of this upgrade include:
 Establish a WAN link between the three sites
 Upgrade the existing LAN and backbones for the three sites
 Provide wireless connectivity to the board room and staff room at the Wellington
site
 Maintain best practice.

4. Topology
 The network topology refers to the logical layout in which devices are connected to
each other.
 An appropriate topology will be selected for the LANs, Backbone and WAN.
 LAN topology defines how devices connect to the backbone.
 Backbone - distribution layer connects LANs to the core layer of the backbone.
 Backbone - core layer connects the distribution layer to the WAN.
 WAN provides a connection between the three sites.

5. LAN Topology
 Devices on the ADTECH LANs will
use a STAR topology, with each
device connecting to a central
distribution device.

6. Backbone Topology
 The central switches of the LANs
will themselves collect to an
upper level of switches, also
using a star topology.
 These switches collectively create
the distribution layer of the
backbone.
 This is a switched backbone
topology.

7. Backbone Topology
 A switched backbone at the
distribution layer provides:
 Reduced costs
 Easier management
 Greater speeds
(Fitzgerald & Dennis, 2009)

8. Backbone Topology
 The distribution layer switches connect to routers,
collectively forming a core layer of the backbone.
 The routers at the core layer use network layer
addresses (IP) to move messages around.
 This means messages can stay within their own LAN
unless addressed outside of it.
 This is a routed backbone topology.

9. WAN Topology
 The routers on the core
layer of the backbone
connect to a central router
known as the core router.
There is one core router at
each of the three ADTECH
sites.
 A fibre-optic line will be
leased to connect the core
routers at each site, in a
bus topology from
Auckland to Wellington to
Christchurch.

10. Connection Media
 Most LANs use Category 5 or 5e cables, which contain four pairs of wires.
 New installations tend to use the newer category 6 Ethernet cable, which supports
Gigabit speeds. (Wells, n.d.) This is the recommendation for our LANs.
 Wireless access in the Wellington office will be supplied using IEEE 802.11ac Wi-Fi
technology.
 Backwards compatibility for 802.11b/g and n will be incorporated into the
hardware.
 The WAN will used a leased fibre-optic connection.

11. Subnets
 Splitting up the networks at each site can drastically reduce network traffic, as
messages can stay within the same subnet unless addressed outside of it (the same
principle behind the routed backbone).
 This is usually done logically – for example a network could be split into different
subnets by department, or by floor.
 The ADTECH network has 225 workstations in Wellington, 200 in Auckland, and 50
in Christchurch.
 A single subnet could technically be used at each site (254 hosts max.), however
the recommendation would be to split each sites network by floor.
 3 subnets in Wellington
 2 subnets in Auckland
 1 subnet in Christchurch

12. Transport/Network/Routing Protocols
 Several packet-switched protocols were considered for this project; X.25,
Asynchronous Transfer Mode (ATM), Frame Relay and Ethernet Services.
 As the majority of our network uses Ethernet connection media, Ethernet services is
the most appropriate service protocol to use as it will require no translation.
 Ethernet services therefore provide much faster speeds, as well as error correction,
and greater compatibility. (Fitzgerald & Dennis, 2009)

13. Transport/Network/Routing Protocols
 Routing protocols considered include Routing Information Protocol (RIP) and Open
Shortest Path First (OSPF).
 The RIP routing protocol is a distance-vector protocol that only considers the
number of hops from source to destination when making routing decisions.
Suitable for smaller networks.
 OSPF is a Link State protocol that not only considers number of hops, but also
circuit speed, and network congestion.
 More comprehensive protocol than RIP
 Recommended for ADTECH network

14. Backbone Technology
As mentioned,
 Routed backbone at core layer
 Switched backbone at distribution layer
Fibre optic connection between the three sites
will be leased from another company, e.g. FX
Networks who operate a 500 GB/s fibre optic
backbone in New Zealand (shared virtually
between subscribers).

15. Wireless LAN Security
Three options considered for securing the wireless LANs in the Wellington office:
 Wired Equivalent Privacy (WEP)
 Wi-Fi Protected Access (WPA)
 Wi-Fi Protected Access II (WPA2)
Of the three encryption protocols, WPA2 is the newest and offers the the greatest
protection. Utilizes Advanced Encryption Standard (AES) to encrypt pre-shared keys
(PSK).
WPA2 offers an Enterprise version which allows each user to have their own password.
(Horowitz, 2009)
WPA2-AES Enterprise is the preferred security protocol for the ADTECH wireless LAN.

16. NetworkDiagram

17. Final Recommendation
 Star LAN topology
 Switched distribution layer backbone
 Routed core layer backbone
 Bus WAN topology
 Category 6 LAN cabling
 802.11ac WiFi with backwards compatibility
 Leased fibre-optic WAN
 Separate subnets per floor in each building
 Ethernet services and OSPF routing protocol
 WPA2-AES Enterprise wireless security protocol

18. References
Fitzgerald, J., & Dennis, A. (2009). Business Data Communications and Networking
(10th ed.). USA: John Wiley & Sons Inc.
Horowitz, M. (2009, September 8). The Best Security for Wireless Networks . Retrieved
from eSecurity Planet:
http://www.esecurityplanet.com/views/article.php/3837976/The-Best- Security-
for-Wireless-Networks.htm
Rtrifunovski. (2014, February 1). Image - Patrick Star.png - MoBrosStudios Wiki:.
Retrieved from wikia.com:
http://mobrosstudios.wikia.com/wiki/File:Patrick_Star.png