Design Teams and Translating Plans into Design Criteria

1. Design Teams and Translating Plans into Design Criteria IACT 424 IACT 924 Corporate Network Design and Implementation

2. Summary Slide • Design Criteria • An Architectural Approach to Network Design • Four(4) Guiding Principles • Legacy System Analysis • Creating Design Teams

3. Design Criteria • Design criteria are the explicit goals that a project must achieve in order to be successful • In recommendation and feasibility reports the design and decision criteria determine the document's final recommendation for action • Managers use these criteria as their basic tool in evaluating a project's potential for success and how well it fits into the goals of the organization • Experts need explicit design and decision criteria in order to evaluate recommended designs of devices and test procedures.

4. Design Criteria • Primary criteria are those that constitute a successful project • the project will be unsuccessful if it does not meet these goals • Secondary criteria are those features that are highly desirable but not absolutely essential

5. Design Criteria • Separating primary and secondary criteria establishes a clear hierarchy in design choices • Implementing one criterion makes the implementation of another infeasible or costly • A secondary criterion may be sacrificed in favour of a primary criterion.

6. Design Criteria • Make your design criteria short but as specific as possible • Avoid vague language • List your primary criteria first • Then list the secondary criteria • Design criteria are often best displayed in bulleted lists • Short titles preceding the explanation • These titles may then be used later in the document to refer to the specific criteria being discussed

7. Design Criteria • If you number your criteria • Avoid referring to them later solely by number • This practice often confuses readers • Use tables to show and summarize the relative effectiveness of different implementations in comparison with your design criteria

8. An Architectural Approach to Network Design • Should not be confused with a detail design of the network • Architectural design is a term that defines • Technologies • Protocols • Communication capabilities • Generic products • interconnection of segments of a network

9. An Architectural Approach to Network Design • Architectural design • Supports the network concepts developed • Expands on the conceptual design • Where organisation-wide strategic directions are set and defined • These are used as a way to identify the network design criteria • criteria that are in line with the organisations direction and technology evolution

10. An Architectural Approach to Network Design – Major Considerations • Development of • The conceptual design • Linked with detailed research on • The business characteristics and process of the organisation • The competition the business is facing • Particularly electronically • What new customer interaction channels are required

11. An Architectural Approach to Network Design – Major Considerations • General technology trends • Technology choices • Lifespan of all technologies that might be utilised in the architecture • User types • Current and planned • Need to be defined

12. An Architectural Approach to Network Design – Major Considerations • Security requirements in the form of an enterprise security policy developed • Current, planned and the potential geographic reach of the network which • Including locations, users and customer/ partner organisations • Definition and identification of applications that run over the converged network

13. An Architectural Approach to Network Design – Major Considerations • Analysis of • Current capacity of the network • Future requirements • Based on • Services • Reach • Applications • Users

14. An Architectural Approach to Network Design – Major Considerations • These will provide • A streamlined design process • Alignment of the network capability with current and future business requirements

15. Outcomes of an Architectural Design • The architectural design will produce a number of outcomes • Design directions • Architecture outline/ overview diagrams for the network segments detailing technology and features/functions. • The architecture design will • Outline high level network topology • Detail interconnections of the network segments • Identify the protocols that will be used

16. Network Architectural Design – Elements • Design elements fall into two categories • Concept elements • Architecture concepts (characteristics) • Technology elements

17. Concept Elements • Business environment • Business developments and direction • New competitors and competitor channels • Current and emerging customer interaction channels • Technology • Available protocol choices • Available/suitable generic product choices (groups) • Ancillary/complementary technologies • Business applications

18. Concept Elements • Scalability • Scalability defined at network segment(s) level • Scalability rules and limits • Dependability • Availability requirements • Recoverability parameters/requirements • Survivability requirements • Fault tolerance requirements

19. Concept Elements • Security • Security requirements (rules and limits set at each network segment level) • Security requirements for user types • Management and maintainability • Management system requirements • Maintainability functions, restore requirements

20. Concept Elements • Compatibility • Compatibility requirements • Compatibility rules between segments • Legacy equipment, systems and protocols • Limitations • Limits for size of network • Limits for volume • Traffic types and traffic mix

21. Concept Elements • Flexibility • Future reach • User demographics and potential changes • Services deployment intent • Distribution and geography • Geographic boundaries of the network (eg distance, location) • Traffic distribution rules (based on geography)

22. Concept Elements • Optimisation and financials • Cost ranges for network, operational and capital • Service dependability versus cost ranges • Risks • Business environment risk • Technology risks (early, lifecycle) • Costs (equipment, installation, operational)

23. Concept Elements • Performance • Objectives for delay/latency • Network throughputs • Potential and identified impairments • Simplicity • Protocol type reduction • Configuration parameter reduction

24. Network Components • Nodes • Node types • Assignment/identification of generic products for node types • Links • Network link types • Assignment/identification of generic products for link types

25. Network Components • Topology • Node distribution, interconnection • Network topology for control and management, interconnections • Interfaces • Applications and users • Other networks • Interface technology types • Protocols

26. Network Components • Services • Communication services types (focus on latency sensitive) • Security services • Management services • Mapping/overlaying services to network topology

27. Network Components • Protocols • Protocols for transport • Protocols for nodes • Protocols for interfaces • Traffic mapping • Segmentation • QoS dependencies • Bandwidth/volumes

28. Four(4) Guiding Principles • The task of writing the design document needs to be guided by the following • Functionality: will the end product work? • Scalability: is the network able to grow without major problems • Adaptability: will the project be able to incorporate new technologies in the future? • Manageability: can we monitor network operations and make necessary changes easily? • May also wish to consider • Standards Compliance • Security • Reduced Institutional Risk

29. Functionality • Functionality: • Does the network support each job function so that strategic goals can be attained? • Does the network deliver end-to-end connectivity that is both reliable and sufficiently fast

30. Scalability • Any network design must allow for future growth • In physical terms, this means • Allowing space in equipment racks for more equipment • Spare connection points in main and intermediate distribution frames (MDFs and IDFs) • In logical terms, well structured IP addressing schemes

31. Adaptability • Design Criteria should incorporate possible changes to design through the advent of new technology • The design should not have features that makes the future provisioning of new technology impossible

32. Manageability • The network should facilitate both monitoring and manageability

33. A Closer Look at Design Requirements • Two important sources of information should be exploited • The Design Requirements section of your Design Document is a summary of requirements that have been developed during your strategic analysis phase. • It also draws on past experience by • Describing the existing network (legacy system) • Listing current applications, protocols, users • Describing the current performance of the network • Brings together all the knowledge that will be used to develop next section, the Design Solution.

34. Characterising the Network • Strategic objectives are used to: • Specify business goals, business processes, customers, suppliers. This has implications for functionality. • Define corporate structure. This has implications for LAN and VLAN design where networks servicing different workgroups need to be separated. • Define geographic structure. This has implications for where workgroups, suppliers, customers are physically located. Mostly relevant to determining WAN typologies.

35. Legacy System Analysis • Identify currently used applications • Necessary in determining how work is currently carried out in the organisation • Information flows should be documented • Including those that are transferred in hard copy, on discs or verbally

36. Legacy System Analysis • New designs have the potential to disrupt established information sharing relationships between people • Shared data sources should be identified • Policy manuals • Servers • Intranets • Bulletin boards

37. Legacy System Analysis • Determine network traffic and access • Identify the amount of data that travels within segments and between segments • Determine the volumes of data that are obtained externally from the Internet. • Determine network performance • Identify protocols in use

38. Network Performance Guide(Teare, 1999) • No shared Ethernet segment to be saturated (no more than 40% network utilisation) • No shared Token Ring segments are saturated (no more than 70% network utilisation) • No WAN links are saturated (no more than 70% network utilisation)

39. Network Performance Guide(Teare, 1999) • Response time <100 milliseconds • No segment have more than 20% broadcasts/multicasts • No segments have more than one CRC (Cyclic Redundancy Check) error per million bytes of data • On Ethernet segments, less than 0.1 % of packets result in collisions • On the Token Ring segments, less than 0.1% of the packets are soft errors not related to ring insertion

40. Network Performance Guide(Teare, 1999) • On FFDI segments, there has been no more than one ring operation per hour not related to ring insertion • Routers are not over-utilised (5 minute CPU utilisation no more than 75% • The number of output queue drops has not exceeded more than 100 in any hour on any router

41. Network Performance Guide(Teare, 1999) • The number of input queue drops has not exceeded more than 50 in any hour on any router • The number of buffer misses has not exceeded more than 25 in an hour on any router • The number of ignored packets has not exceeded more than 10 in an hour on any interface on a router

42. Creating Design Teams • Different skills are required of project leaders through the life of a project. • In the early stages, the emphasis should be on leadership • In the later stages, the emphasis should be on management

43. Leadership and Management (Verma, 1996, p. 223)

44. The people you’ll need • Telecommunications Manager • Conceptualiser & visionary • Articulate & persuasive • Understand organisations problems & how communications tech can be applied to them • Able to grasp technical subjects but doesn’t have to be a ‘techie’ • Able to plan & make decisions

45. The people you’ll need • Designers & Implementers • Good understanding of communications systems & products • Creative & innovative • Project management skills • Verbal & written communications skills • Team player

46. The people you’ll need • Network operations staff • the ‘manufacturing’ arm • Service oriented • Strongly motivated to maintain the system • Good verbal skills with ‘customers’ • Able to swap between sections (say: network ops & computer ops) to spread skills and experience

47. The people you’ll need • Technical support staff • Understand hardware & software • Self-starters • Analytical problem solvers • Often have advanced technical education, frequently vendor based • Novel • Microsoft • Cisco etc.

48. The people you’ll need • Administrative support staff • Largely clerical • Some grasp of IT issues & jargon • Accounting & business administration skills