Building a Corporate Network – A Case Study

Objectives

• At the end of this case study you will be able to– Transfer a business communication requirements into a

data network requirement– Describe the primary components that constitutes a data

network– Identify the basic elements of LAN, WAN and Security sub

systems– Prescribe a high level network structure for a generic

corporate data network

Acme Corporation• Acme Corporation is a multinational organization who has two of their

manufacturing plants in Sri Lanka. They produce automobile tires for export and local market. The main factory and head office is located at Kelaniya and another factory at BOI zone, Katunayake. They have a warehouse at Peliyagoda and a raw material store at Thalawakale.

Acme Corp need to build a data network to deploy their new ERP (Enterprise Resource Planning) application. The Katunayake factory and Peliyagoda warehouse are to be connected online to the head office and the raw material store is to be connected for batch processing via a dial up facility.

In addition they need to have Internet connectivity, a local web site and E-mail service for their staff. Staff from corporate head quarters (abroad) and telecommuters in Sri Lanka need to gain access to Acme Corp network for various activities. Data and network security are concerns of the network administrator.

Acme Corporation (Cont’d)

Head Office / Main Factory(Kelaniya)

Warehouse(Peliyagoda)

Telecommuters

Branch Factory(BOI Zone - Katunayake)

Mobile Users

Raw Material Stores(Thalawakale)

Internet

Network Elements• User and server local connectivity at head office, branch, warehouse and store

– Network switches and devices– Cabling infrastructure (copper/fiber)

• Wide area interconnectivity– Routers– Links from a network service provider

• Internet connectivity– Router– Internet connection from as Internet Service Provider (ISP)

• Security– Firewall– Virtual Private Network (VPN) device

• Telecommuting– Remote access server– Modems– Telephone lines

• Wireless connectivity at head office– Wireless access point

• Network address planning

Branch LAN

• Branch, Warehouse & Stores LAN Devices– 10/100 Base-TX Autosense Ethernet Switch - 03 nos.– Copper (UTP) Cable plant at all 03 locations

Branch Factory

10/100 Base-TX

Warehouse

10/100 Base-TX

Stores

10/100 Base-TX

Head Office LAN

Floor 2

Floor 1

Floor 3

Optical FibreUplinks

100 Base-FX

10/100 Base-TX

10/100 Base-TX

ERP Server and other shared Resources

Network PrinterWirelessAccess Point

Mobile Users10/100 Base-TX

Head Office LAN (cont’d)

• Head Office LAN Components– 10/100 Base-TX Autosense Ethernet Switch – 03

nos.– Optical fiber transceivers – 4 nos.– Wireless Access Point – 1 no.– Copper (UTP) / Fiber Cable plant

Wide Area Network

Modem

Modem

Ethernet

Ethernet

Leased Line

Router

RouterHead Office

Branch Factory

Warehouse

Stores

Modem

DSU/CSU

DSU/CSU

Ethernet

DSU/CSU

DSU/CSU

Router

Ethernet

Modem

Modem

Router

PSTN

Wide Area Network (cont’d)• WAN Components– Routers – 4 nos.– DSU/CSUs – 4 nos.

• (Digital Service Units/Channel Service Units)

– Modems (synchronous) – 5 nos.– Leased Lines – 2 nos.

• Head Office ↔ Branch Factory• Head Office ↔ Warehouse

– PSTN Links (Telephone lines) – 5 nos.• Head Office – 2 nos.• Branch Factory – 1 no.• Warehouse – 1 no.• Stores - 1 no.

WAN Connectivity Options• Leased Links / Clear Channel Circuits

– Dead copper loops– Active copper loops– Microwave point-to-point links– Microwave point-to-multi point access system– PDH/SDH* transmission networks – Satellite links– Dark fiber loop – Free space optics (laser)

• Public Switched Data Networks– Frame Relay– ATM

• Public IP Backbone– Multi Protocol Label Switching (MPLS) IP backbone – VPN over Internet– Packet over SONET/SDH

PDH – Pleisiochronous Digital Hierarchy SDH – Synchronous Digital Hierarchy

WAN Data rates• Link speeds– DS0 - 64 kbps– 128 / 256 / 512 / 1024 kbps– E1 – 2 Mbps– E3 – 34 Mbps– OC-3c / STM-1 – 155 Mbps– OC-12 / STM-4 – 622 Mbps– OC-48 / STM-16 – 2.488 Gbps– Gigabit Ethernet – 1,000 Mbps – 10 Gigabit Ethernet - 10 Gbps– Fiber Channel – 2 Gbps

Uses OSI Layer 2 FramingProtocols

Dial-up Services• Dial Backup– to recover from failed links

• Dial on Demand– to provide on demand access and disconnect while

idling• Bandwidth on Demand– to provide increased bandwidth during congestion

• Options– PSTN – Public Switched Telephone Network– ISDN – Integrated Service Digital Network

Internet Connectivity14

Unprotected Network De-militarized Zone Secure Network

10/100 Base-TX

Internet

Router Firewall

VPN Gateway

Web Server andMail Server

ISP

DSU/CSUERP Server and other shared Resources

Downlinks to 2nd and 1st Floors

To Router

Firewall Security Policy

Internet

Router Firewall

VPN Gateway

Web Server andMail Server

ISP

DSU/CSU

ERP Server and other shared Resources

Corporate users’ Internet Access

No access

OutgoingMail

Incoming Web, MailVPN connections

Web, Mail server connections

Downlinks to 2nd and 1st Floors

To Router

Secure Access to ERP Server

Internet

Router Firewall

VPN Gateway

Web Server andMail Server

ISP

DSU/CSU

ERP Server and other shared Resources

Client at Headquarters • Encrypted• Authenticated• Authorized• Accounted …. access only.

Downlinks to 2nd and 1st Floors

To Router

Internet and Security

• Internet connectivity– Router – 1 no.– DSU/CSU – 1 no.– ISP connection – 1 no.

• Security– Firewall – 1 no.– VPN Gateway device – 1 no.

Remote Access Service

RAS ComponentsRemote Access Server – 1 no.Modems (Asynchronous) – 4 nos.PSTN (telephone) lines – 4 nos.

PSTN

Ethernet (DMZ)

Remote Access Server

Modem Pool

Home User

NotebookComputer

Complete Head Office Network

ERP Server and other shared Resources

Leased LineDSU/CSU

DSU/CSU

Modem

Modem

Router

PSTN

VPN Gateway

Internet

Router Firewall

ISP

DSU/CSU

WirelessAccess Point

Mobile Users

RemoteAccessServer

Modem PoolWeb Server and

Mail Server

Bill of Material

Head Office Branch Warehouse Store Total

Ethernet Switch 3 1 1 1 6

Optical Transceivers 4       4

Router 2 1 1 1 5

DSU/CSU 3 1 1   5

Modem (Sync.) 2 1 1 1 5

Remote Access Server 1       1

Modem (Async.) 4       4

Firewall 1       1

VPN Gateway 1       1

Wireless AP  1       1 

Cable Plant

Summary

• Business requirement• Network requirement• Local area network• Wide area network• Internet connectivity• Firewall and VPN

Thank you