Multistory Building LAN:Performance comparison of various network

architectures

Daisy Chain Versus Collapsed Backbone Architecture

Lab Objective

• This lab teaches the application performance of two different network architectures: Daisy Chain and Collapsed Backbone Network.– Collapsed backbone data network consists of a core

switch in the basement. The core switch is linked directly to a workgroup switch on each floor.

– In daisy chain architecture, the basement core switch is linked directly to the first floor switch, the first floor switch is linked directly to the second floor switch, and so forth.

Network Overview

• The HBL Operations building has 10 floors, each having many users connected to a 10Base-T workgroup switch in the floor’s telecommunications closet. The users share an Oracle server and seven file and print servers in the basement.– In Scenario 1, the switches on each floor are daisy

chained to the core switch in the basement. We will see that this daisy chain approach introduces high application latency to users on the highest floor.

– In Scenario 2, the daisy chain topology is retained, but the core switch is moved to the fifth floor. We will see that this reduces latency on the highest floor but increases it on the bottom floor.

– In Scenario 3, the core switch is kept in the basement, but a collapsed backbone topology is used, in which the core switch in the basement is linked directly to the workgroup switch on each floor.

Scenario1 (Daisy chain)• 11 Ethernet switches• 10 LANs – with 70, 175, 110, 85,

50, 150, 100, 200, 125, 95 users on each floor respectively

• 1 subnet– With 7 file Print and

Email servers

• 1 Database Server

Applications and Profiles

• Applications:– File Printing (B/W pages)– Email (Low Load)– Database (High Load)

• Profiles:– Email– File Printing– Database

Profiles on LANs

• Floor1: Email, DB• Floor2: Email• Floor3: Email, File Print• Floor4: File Printing• Floor5: Email, DB• Floor6, 7, 8: Email• Floor9: File Printing• Floor10: DB

Statistics and Comparison

• Collect statistics of Application Response time of users on Floor 1, 5 and 10

• Compare the results of application response time on these floors.

• Analyze the results and answer:– Why the users on 10th floor are observing higher

application response time?

Scenario2 (Daisy Chain)

• Company decides to restructures the network at no additional hardware cost to achieve better application performance for users on upper floors

Comparison of Response time

• Compare the Application Response Times for users on different floors considering both scenarios.

• We expect that restructuring the network should reduce the application response times for users on upper floors

LAB Task 1

• Restructure the network with collapsed backbone architecture.

• Compare the application response time for all three scenarios.

Lab Task 2

• Restructure the network with BUS backbone architecture with same specifications as in previous scenarios.

• Compare Application response time of BUS backbone network with that of Collapsed backbone architecture.

Lab Report

• Prepare a brief report giving your conclusions. Do not simply repeat the results of the simulations.

• Give your recommendation for what the firm should do. Consider relative cabling costs in your recommendation.