Chapter 14 Managerial issues in networking

Overview Network design Network management – Hardware – Software Technology standards Role of government and legal process 2

Introduction Cost containment and formal design not critical for typical home network Large networks need formal methods for design and management – To contain costs while meeting user needs – Standard designs and practices have been developed in the industry based on experience 3

Network design Formal design process is useful Successful design ensures that Basic systems analysis and design principles can be adapted to network design 4

Requirements analysis Fortunately modern network technologies meet most typical user needs Some pockets of intense use may exist 5

Logical network design Based on user input and prior experience, requirements analysis identifies network needs Logical network design represents network requirements in a form that Drawing is a very good idea 6

Logical network design Should show for every area of the network – Total number of general-purpose desktops – Shared devices such as printers – Devices with special network needs, e.g servers – Subnets – Network services such as DNS, DHCP – Network security and management utilities such as firewalls 7

Logical network design example Consider an example of a small business specializing in video production – Editing group needs high bandwidth connectivity to its storage network – Other groups only need plain desktop connectivity IT Administration – Extra network ports provisioned in every subnet for future expansion 8

Logical network design example 9

Physical network design Logical design reviewed by IT and end users Physical network design indicates the technologies that will be used to implement the logical design 10

Physical network design example 11

Implementation Networks in young organizations often use best-of-breed As organizations mature, designs are often implemented using a common set of technologies Design in example could also have used 1 gbps Ethernet ports throughout the company 12

Campus network Computer networks typically fall into three categories – Building networks Smallest network unit Design standardized from experience – Campus networks Span multiple buildings in close vicinity Typical state university – Enterprise networks Network scattered across campuses Uses WAN technologies 13

Campus network example 14

Campus networks Typically have three layers – Core layer – Distribution layer – Access layer Core layer – Optimized for fast packet handling and availability – Routers only responsible for forwarding to appropriate distribution layer device 15

Campus networks Distribution layer – Organizes network into subnets – Handles routing – Implements administrative policies using firewall etc – Can offer network services such as DNS, DHCP – Handles Internet connection Access layer – Provides network ports to end users – Can offer network services such as DNS, DHCP – Typically uses building network architecture 16

Enterprise networks Successful organizations add offices in other cities, states and countries Campuses need to be connected to each other using WAN technologies Some campuses could be small 17

Enterprise networks 18

Network maintenance Networks need ongoing maintenance for performance – activities performed to keep networks in a serviceable condition or to restore them to serviceability – Includes activities such as inspection, testing, and servicing Two categories of assets – Hardware – Software 19

Hardware maintenance Typical network may have hundreds of devices Manual monitoring is very expensive Two components – Management station – Network agents 20

Network management with SNMP 21

Hardware maintenance Network agents store information about their device in a management information base (MIB) – MIB only contains information necessary for fault management or configuration management Management station uses SNMP protocol to set or retrieve values from the MIB 22

Software maintenance One of the biggest concerns in software maintenance is patching Tools have been developed to automatically scan all networked software on every device on the network – Confirm application of patches and other utilities – Nessus is a popular free tool 23

Nessus scan 24

Standards Communication on the Internet almost always works Compare smooth connectivity on the Internet to other environments 25

Standards Most technologies used on the Internet follow standards – documents, established by consensus and approved by a recognized body that help achieve high degree of order – Products that comply with standards can easily inter-operate with other devices compliant with the same standard TCP/ IP, Ethernet are standards 26

Standards creation Typically follows well-established procedure – Expert organization takes lead Develops requirements for the new standard – Meet communication needs that can be economically satisfied with available technology – Technology solutions are proposed by interested organizations – Proposed solutions are evaluated – Solution with overwhelming majority becomes standard E.g. development of IEEE n standard 27

Government involvement Technological development is mostly led by private sector However, government has played a key role in the development of networking technologies – Packetization by Department of Defense – Early Internet by National Science Foundation – Web browser by National Science Foundation – Allocation of wireless spectrum by the FCC 28

Legal process Development of the phone network was influenced by judicial and legislative actions – Modified final judgment (1982) introduced competition in long distance phone service Judicial action – Telecommunications act of 1996 introduced competition in local phone service Legislative action Net neutrality debate is ongoing 29

Summary Formal network design process helps networks meet end user requirements most effectively Automated network maintenance is important to keep large networks operational Standards enable inter-operability of communication equipment Government and legal process have played critical roles in helping the evolution of communication technologies

Case study Telework and telecommuting – Networks are changing how we work – Over 20% of the US workforce telecommutes Networks bring resources to places where they would otherwise be unavailable – Haiti earthquake, Jan 12, 2010 – Ongoing medical care Local specialists access the expertise of physicians in Miami and other places

Hands-on exercise OPNET LAN project

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