Notes04

IS 483 Lecture 4 Oct 3 2005 1

IS 483 Lecture 4IS/IT Functions and Structures


Team Exercise See

http://facweb.cs.depaul.edu/nsutcliffe/483-00Currwork/Notes04exercise.doc

a. What does the strategic focus tell? What is now the new decision criteria for IT? b. What choices for locating computing centers? What is apropos for IT personnel? c. What alignment is best starting point using what criteria? d. Describe 4 basic governance pressures and its role in IT history – what should the aim be?

http://facweb.cs.depaul.edu/nsutcliffe/483-00Currwork/Notes04exercise.doc


AgendaService Oriented Architecture

LANs and WANs

Internets/Extranets/Intranets

Architecture Management

Service Level Agreements


IT/IS Organizational ModelsPlacement Organizational models are the basic ways that people

structure the IT function within an organization. Typically placement of computing/communication resources and the placement of IT personnel are the most important.

Location of computing resources Centralized Decentralized Distributed

Placement of IT Personnel Aligned to User areas Aligned to computing resources


Service Oriented Architecture Groups of software components that carry out business

processes An architecture built around a collection of reusable

components with well-defined interfaces.Evolves from CORBA* which revolves around tightly coupled

objects to loosely coupled services using well-defined interfaces,

such as web services.

Common Object Request Broker Architecture (CORBA) is an architecture and specification for creating, distributing, and managing distributed program object s in a network.


Service Oriented Architecture Benefits

Can integrate “everything but the kitchen sink” Easier integration process using:

SOAP (Simple Object Access Protocol) WSDL (Web Services Description Language)

Better business / technical dialogue along meeting business needs (services)

Assists all in rethinking around best practices for running business

Greater ROI through Easier integration Increased agility


SOA and Web Services Web Services – can be alone SOA – can be alone Web Services + SOA >> ideal synergy E.g. right data gets to right person


SOA challenges Security on open architecture more difficult Managing complex services configuration

more difficult Network monitoring more difficult Costs are higher


Building SOA Blueprint is mandatory for

Focus on goals

Need to identify service levels to provide before building

Need to prioritize services to put in SOA to those that do most good and have less need to near real time responses


Data Networks Collection of technologies that get data from one

computer to another Include

Clients Servers Routers Switches Topologies Protocols Hubs Cable (copper or fiber)


Servers Types:

Basic file and print Database (includes DBMS) Application Web


Servers: Configuration Considerations Processor and Memory Disk Storage Fault Tolerance

Redundant power supplies Disk Drives: RAID levels

(Redundant Array of Independent/Inexpensive Disks) Redundant Network Interface Cards Uninterruptible Power Supplies Cross Connecting Clustered Servers Backup

Support from vendor


Local Area Networks Design goals

Maximize traffic efficiency Reliability Manageability Flexibility

Location of Devices determines location of: Hubs Backbones

Traffic Volume characteristics is a major design issue Low volume email vs high volume animation Pattern between servers


Local Area Network Bus Typology

Ethernet Communication Technology

Most popular


Local Area Network Ring Typology

Token-RingCommunication Technology


Local Area Network Star Typology


Network Backbone High-capacity portion of the LAN that carries

data from lower-speed parts of the network that connect to it. From single piece of hardware To fiber ring connecting 30 floors of building


Hubs and Concentrators Chassis versus Stackable

Stackable – cheaper and convenient Chassis – redundant power supplies,

high-end options

Passive versus Active Active can regenerate signal

Shared versus Switched Switched – expensive/superior performance


Wiring Copper Fiber


LAN: Management Finding problems thru Network Management

System software Network Monitoring

SNMP (Simple N/W Mgt Protocol RMON (Remote Monitoring) – expanded SNMP for

analysis, traffic statistics, bottlenecks Expansion

Multiple wire runs Easily upgradeable hardware Costs are mostly one time for construction


WAN: Wide Area Networks Network that connects the remote locations via

telecommunications facilities Costs are mostly recurring for leasing lines Design Considerations

Geography Traffic flow Volumes High-speed transmission need 24 x 7 need Backup/fail-over capabilities Installation delays


WAN Technologies Point-to-Point Circuits

Aka leased, dedicated, private lines Dial-up lines

POTS (plain old telephone system) ISDN –over copper lines DSL – over copper lines

Packet switching ATM and Frame Relay Virtual Private Network

Cable modems


WAN Third Parties can manage for you LAN tools can also manage WAN


Cable Plant Def. The physical wire used in your facility that

connects all the network devices, the design of the wiring layout, and all components that are used within it.

Unique investment issues Cost is in labor of installation, not material Once installed, access is virtually lost Can’t take capital investment with you No upgrades, only replacements Capital investment that outlives all other


Cable Plant: Design Factors LAN technologies used: (ethernet, token-ring) Distances Exposure to hazards Bandwidth requirements Existing networking equipment Local building code requirements Nodes (#) per collision domain


Managing a Cable Plant Maintain wiring diagrams & keep current Label both ends of cables Keep wires organized Check wires with software Check wire closets for heat, mice, water


Miscellaneous Concerns Wireless --Expanding by leaps and bounds Remote Access – Needed?

Direct line Web-based

Network Security Issues Dial-Back RADIUS Kerberos PPTP IPsec


Internet/Intranets/Extranets Internet – a web site that a sponsor makes

available for every user on the web who wants to see it.

Intranet – a web site that is only available to those that the owner says can see it.

Extranet – a web site that only available to those in associated organizations.


Overall Goals for Web Sites Informing Entertaining Selling products and services Generating sale leads


E-Commerce Conducting business transactions over the

web Raises revenues 10-20% Reduces costs 20-45& Asset intensity reduced 20 to -60% Types:

Business-to-consumer (B2C) Business-to-business (B2B)


E-Commerce Startup Issues Getting your customers to know your site Site must be fast and communicative Site must be able to handle the business Site must be secure


E-Commerce Technical Elements Shopping carts Payment processing Shipping and handling calculations Security provisions Data exchanges with other business

applications


Web Site Concerns Content Design Programming Hosting – often outsourced to ISPs


ISP Evaluation Criteria ISP is a provider who provides connections to

the internet– choice is based on: Speed Reliability:

multiple lines Cost Email backup concerns -- SOX



Architectures – Client/Server A versatile, message-based and modular

infrastructure that is intended to improve: Usability Flexibility Interoperability Scalability

Other architectures Mainframe (all done on a central processor) with dumb

terminals File Sharing (files downloaded/uploaded) to/from PCs to

server


Architectures – Client/Server Two-tier

Client – system interface and perhaps processing Server – data and processing

Three-tier Client – system interface Middle tier – transaction processing monitor

-- message servers-- application servers

Server Data Server Application processing


Architecture Management Organizational Framework

Executive Steering Committee Senior managers Chaired by CIO

Task Force Half are users Works part-time 20/80 Reports to Head of IT architecture


Architecture Management Goals based on business drivers

Low-cost execution Fast development time Flexibility for modification High availability/reliability Etc.


Service Level Agreements Reasons for developing

Newly implemented SLM strategy New technology is going “live” Customer concerns on IT service delivery Customer desire to choose how much service they

want


Service Level Agreements 5 elements of good SLAs

Descriptions of service Service standards Duration Roles and responsibilities

The customer representative Service level manager

Evaluation criteria


Service Level Agreements 5 mistakes

Lack of organizational readiness Lengthy or too technical language Lack of support Poor customer focus Unrealistic performance targets


Next week http://facweb.cs.depaul.edu/nsutcliffe/483-00Currwork/LinksWeekly.htm#5

http://facweb.cs.depaul.edu/nsutcliffe/483-00Currwork/LinksWeekly.htm#Service Oriented Architecture




Notes04

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