MM Clements Introduction

Course details Advanced Switching & Network Troubleshooting ELEE1065 Advanced Network Design ELEE1121 Taught together but assessed differently Lecturing staff: – MM Clements, Indy Kang, Kanti Chhabhadiya ASNT & AND 2

Division of course Term 1 will focus on advanced routing and troubleshooting – Taught by Indy Kang & Mark Clements Term 2 will focus on layer 2 switching – Taught by Kanti Chhabhadiya ASNT & AND 3

Assignments 4 assignments – Practical routing design20% – Network administration20% – Practical switching design20% – Network troubleshooting report20% 2 examinations in May – Routing examination15% – Switching examination15% ASNT & AND 4

Any questions? ASNT & AND 5

Campus Networks ASNT & AND MM Clements

ASNT & AND 7 Campus Networks Characteristics of campus networks Differences between ‘old’ networks and their design Old and new design principles Characteristics of well-designed networks Responsivity & efficiency Deep packet inspection

ASNT & AND 8 Campus Networks An autonomous network under the management of a single entity Exists on a university campus or within a local geographic area such as a business park, a government, research, or medical centre May be managed by a single entity, but used by different organizations Can provide access path into a larger network, e.g. MAN or the Internet.

ASNT & AND 9 Design Issues of a Campus Network Traditional design issues can involve: – type of media to be used between buildings – outside cable specifications – rights-of-way – avoidance of natural barriers – underground or aerial cabling requirements – line of site for inter-building wireless transmissions – security issues (e.g. exposed cables may be tapped or cut)

ASNT & AND 10 Other design issues Not necessarily a "backbone network" but may be designed with a backbone topology There are also access issues for the users and/or customers that connect to the network such as whether they are charged for usage. Individual networks within buildings typically connect to the campus network via routers. Hierarchical topologies using high-performance switches may also be used.

ASNT & AND 11 Characteristics of a well-designed network FIVE main characteristics of a Scaleable Internetwork 1. Reliability and Availability 2. Responsivity 3. Efficiency 4. Adaptability 5. Accessibility and Security (See last year’s notes for details)

ASNT & AND 12 Responsivity and Efficiency End users will notice any poor responsivity Responsivity may be affected by efficiency Today’s applications becoming more ‘chatty’ Streaming video e.g.Youtube demand BW Online games e.g. Secondlife greedy for BW This can have a detrimental effect on the network performance as a whole

ASNT & AND 13 Older Network Function (1990s) Limited networked applications Little real-time network demand Much client-server Sufficient to provide a bit-pipe between points in the network Took little notice of traffic types All traffic given equal priority 3 layer model used for design

ASNT & AND 14 Traditional 3 Tier Design Model

ASNT & AND 15 Poor performance today The bit-pipe approach to network design is becoming ‘long in the tooth’ Applications specific to the enterprise day-to- day work are suffering due to lack of BW Many more BW hungry apps around today Some may not be legal, some may hinder the required functions of the network

ASNT & AND 16 Solution to Design Need to examine network traffic Prioritisation can be achieved by inspecting packet contents Needs specialised machines Cannot violate 3 tier model Where should this intelligence be implemented?

ASNT & AND 17 Deep packet inspection Can this occur in core? No – core is just for high speed delivery Can this occur at access layer? No, this is usually low-end hardware Distribution layer is logical place for the ‘new intelligence’

ASNT & AND 18 Conclusion Rethink needed in network design in the light of current network traffic trends Consideration given to essential traffic 3 Tier model still valid – Adjustments only required Distribution layer to be tasked with intelligence for deep packet inspection

ASNT & AND 19 References The Encyclopedia of Networking and Telecommunications ( White paper “Gigabit Campus Network Design—Principles and Architecture” Cisco Systems