Search network equipments for network design


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Search network equipments for network design

  1. 1. Tutorial of Network Design and Practice to Search Network Devices <ul><li>Learn network design principles from this presentation and network design chapter. </li></ul><ul><li>According to requirements in your coursework 1, search network devices from the Internet. </li></ul><ul><li>It takes 5 weeks to design a network and submit your design in the end of week 5. </li></ul><ul><li>Some websites for manufactures are listed in following slide. </li></ul>
  2. 2. Some of Network Devices Manufacturers Cisco: 3Com: Huawei: Star-Net: D-link: Nortel:
  3. 3. Cisco Small Business Smart Switch SLM2008 £93.4 Interfaces/Connections : 7 x network - Ethernet 10Base-T/100Base-TX/1000Base-T - RJ-45 1 x network / power - Ethernet 10Base-T/100Base-TX/1000Base-T - RJ-45 Data Transfer Rate : 1 Gbps MAC Address Table Size : 8K entries Remote Management Protocol : HTTP Features : Layer 2 switching, auto-sensing per device, auto-negotiation, VLAN support, auto-uplink (auto MDI/MDI-X), IGMP snooping, port mirroring, store and forward, Broadcast Storm Control, firmware upgradable, Quality of Service (QoS) Dimensions (WxDxH) / Weight : 13 cm x 13 cm x 2.9 cm / 420 g Manufacturer Warranty : 5 years warranty
  4. 4. Network Design <ul><li>Design goals </li></ul><ul><li>Design choices </li></ul><ul><li>Design approaches </li></ul><ul><li>The design process </li></ul><ul><li>Capacity planning </li></ul>
  5. 5. Design goals <ul><li>Good designs should: </li></ul><ul><ul><li>Deliver services requested by users </li></ul></ul><ul><ul><li>Deliver acceptable throughput and response times </li></ul></ul><ul><ul><li>Be within budget and maximise cost efficiencies </li></ul></ul><ul><ul><li>Be reliable </li></ul></ul><ul><ul><li>Be expandable without major redesign </li></ul></ul><ul><ul><li>Be manageable by maintenance and support staff </li></ul></ul><ul><ul><li>Be well documented </li></ul></ul>
  6. 6. Design Choices <ul><li>Balance of distribution </li></ul><ul><li>Level of transparency </li></ul><ul><li>Security </li></ul><ul><li>Connectivity technology </li></ul>
  7. 7. Design approaches <ul><li>Two typical methods </li></ul><ul><ul><li>Traditional analytic design </li></ul></ul><ul><ul><li>Building block approach </li></ul></ul><ul><li>Both use a similar iterative approach </li></ul>
  8. 8. The traditional design process
  9. 9. Design Stages - Agree requirements <ul><li>Engage end users </li></ul><ul><li>Translate requirements </li></ul><ul><ul><li>Business objectives –> technical specification </li></ul></ul><ul><li>Phasing the requirements </li></ul><ul><ul><li>Right level of detail at each design stage </li></ul></ul><ul><li>Designing the requirements </li></ul>
  10. 10. Design Stages - Designing the requirements <ul><li>Aim for completeness </li></ul><ul><li>Prioritise with a hierarchical system such as </li></ul><ul><ul><ul><li>[M] - Mandatory </li></ul></ul></ul><ul><ul><ul><li>[H] – Highly desirable </li></ul></ul></ul><ul><ul><ul><li>[D] - Desirable </li></ul></ul></ul><ul><ul><ul><li>[N] - Note </li></ul></ul></ul>
  11. 11. Design Stages - Assessing requirements <ul><li>Consider all aspects </li></ul><ul><ul><li>E.g. support & maintenance, depreciation, commissioning costs, project management fees, hardware & software upgrade costs, backup devices costs, consultancy charges – over the lifetime of the network </li></ul></ul><ul><li>Weighted matrix multipliers </li></ul><ul><ul><li>M=100, H=10, D=1, N=0 </li></ul></ul><ul><ul><li>Produce scores and rank suppliers </li></ul></ul>
  12. 12. Design Stages - Information gathering <ul><li>Need to find details of user behaviour, application use and location information for example: </li></ul><ul><ul><li>User: location, numbers, services used, typical access </li></ul></ul><ul><ul><li>Sites: number, location, constraints on traffic (security, political or cost) </li></ul></ul><ul><ul><li>Servers and services: location, level of distribution </li></ul></ul><ul><ul><li>WAN/backbone predicted link traffic </li></ul></ul><ul><ul><li>Protocol support: bridged, routed or switched – Gateways needed? </li></ul></ul><ul><ul><li>Legacy support: equipment, protocols or services </li></ul></ul><ul><ul><li>Specific availability needs? 24-hour/backup links etc </li></ul></ul><ul><ul><li>Five-year plan – changes to population or business requirements </li></ul></ul><ul><ul><li>Budgetary constraints </li></ul></ul><ul><ul><li>Greenfield or existing site </li></ul></ul><ul><li>Information is refined and leads to a requirements database and capacity plan </li></ul>
  13. 13. Design Stages - Site constraints <ul><li>Greenfield or </li></ul><ul><ul><li>Greenfield sites have no legacy constraints but… </li></ul></ul><ul><ul><li>It is difficult to determine the real network loads and stresses </li></ul></ul><ul><ul><li>Needs more detail of application use and underlying protocols </li></ul></ul><ul><ul><li>Could use simulation to predict performance </li></ul></ul><ul><li>Existing site </li></ul><ul><ul><li>Limited access </li></ul></ul><ul><ul><li>Access to live network could be restricted but… </li></ul></ul><ul><ul><li>Bottlenecks more obvious </li></ul></ul><ul><ul><li>Can use traffic/network analysis tools </li></ul></ul>
  14. 14. Design Stages - Planning <ul><li>Uses information on </li></ul><ul><ul><li>Hosts, users, services, and their internetworking needs </li></ul></ul><ul><li>Iterative process of </li></ul><ul><ul><li>Conceptual design </li></ul></ul><ul><ul><li>Analysis </li></ul></ul><ul><ul><li>Refinement </li></ul></ul><ul><li>Involving </li></ul><ul><ul><li>Brainstorming, design reviews, modelling tools </li></ul></ul><ul><li>Leading to final draft design </li></ul>
  15. 15. Design Stages - Design specification <ul><li>Detailed document of the design </li></ul><ul><ul><li>Acts as a benchmark for design changes </li></ul></ul><ul><ul><li>Final design choices and changes need justification and documenting </li></ul></ul><ul><ul><li>Should include change history to aid maintenance </li></ul></ul><ul><ul><li>Used for the implementation </li></ul></ul>
  16. 16. Design Stages - Implementation <ul><li>Needs a project plan to include </li></ul><ul><ul><li>Phased introduction of new technology </li></ul></ul><ul><ul><li>Educating the users (what to expect) </li></ul></ul><ul><ul><li>Pilot installation (test for possible problems) </li></ul></ul><ul><ul><li>Acceptance testing (to prove performance meets requirements) </li></ul></ul><ul><ul><li>Deployment (provide support on going live and provide fallback position) </li></ul></ul>
  17. 17. Connectivity options <ul><li>Technology choices </li></ul><ul><ul><li>LANs (Ethernet, Token ring, ATM) </li></ul></ul><ul><ul><li>MANs (FDDI, SMDS, ATM, SONET/SDH) </li></ul></ul><ul><ul><li>WANS (Frame relay, ATM, ISDN, X.25, PDCs, Satellite) </li></ul></ul><ul><ul><li>Wireless (802.11, Bluetooth, GPRS, GSM) </li></ul></ul><ul><ul><li>Dial-up lines </li></ul></ul><ul><ul><li>Serial links </li></ul></ul>LAN(Local area network, MAN (metropolitan area network), WAN (wide area network )
  18. 18. Connectivity option determinants <ul><li>Packet, cell or circuit switching </li></ul><ul><li>Wired or wireless </li></ul><ul><li>Distance </li></ul><ul><li>Performance </li></ul><ul><li>Bandwidth </li></ul><ul><li>Quality of Service </li></ul><ul><li>Availability </li></ul>
  19. 19. Media and bandwidth choices
  20. 20. Capacity Planning - Outline <ul><li>Concerned with </li></ul><ul><ul><li>User response times </li></ul></ul><ul><ul><li>Application behaviour and performance characteristics </li></ul></ul><ul><ul><li>Network utilisation </li></ul></ul><ul><li>Needed to </li></ul><ul><ul><li>Minimise downtime </li></ul></ul><ul><ul><li>Maximise service to customers </li></ul></ul><ul><ul><li>Minimise costs of procurement and maintenance </li></ul></ul><ul><ul><li>Avoid unscheduled maintenance or re-design </li></ul></ul><ul><ul><li>Avoid costly upgrades and bad publicity </li></ul></ul>
  21. 21. Capacity Planning - Stages <ul><li>Form a discussion group (involve users etc.) </li></ul><ul><li>Quantify user behaviour </li></ul><ul><li>Quantify Application behaviour </li></ul><ul><li>Baseline existing network </li></ul><ul><ul><li>Traffic profiles </li></ul></ul><ul><li>Make traffic projections </li></ul><ul><li>Summarize input data for design process </li></ul><ul><li>Assess other data (environmental, location restrictions, deployment constraints etc) </li></ul>
  22. 22. Capacity Planning – Step 1 <ul><li>Form a discussion group (involve users etc.) </li></ul><ul><ul><li>Needs wide representation </li></ul></ul><ul><ul><li>Users, network managers, application groups </li></ul></ul><ul><li>To elicit </li></ul><ul><ul><li>What uses find acceptable and unacceptable </li></ul></ul><ul><ul><li>Map of services and details of user behaviour </li></ul></ul><ul><li>Quantify items using </li></ul><ul><ul><li>User and service sizing data </li></ul></ul><ul><ul><li>Snapshots from data capture and network management tools </li></ul></ul><ul><ul><li>Traces of key services using protocol analysers </li></ul></ul><ul><ul><li>Pilot network implementation </li></ul></ul>
  23. 23. Capacity Planning – Step 2 <ul><li>Quantify user behaviour </li></ul><ul><ul><li>Need to know population and and location of users </li></ul></ul><ul><ul><li>Summary of major user groups </li></ul></ul><ul><ul><li>Application use by user group </li></ul></ul><ul><ul><li>Site location data (country, grid ref., town, postcode, telephone exchange) </li></ul></ul><ul><ul><li>Planned changes </li></ul></ul>
  24. 24. Capacity Planning – Step 3 <ul><li>Quantify Application behaviour </li></ul><ul><ul><li>Need to identify </li></ul></ul><ul><ul><ul><li>Applications that could affect performance </li></ul></ul></ul><ul><ul><ul><li>Location and performance of servers and clients </li></ul></ul></ul><ul><ul><ul><li>Key constraints on performance (response times, buffer sizes etc </li></ul></ul></ul><ul><ul><li>And define </li></ul></ul><ul><ul><ul><li>Application behaviour under fault conditions (lost data) </li></ul></ul></ul><ul><ul><ul><li>Addressing mechanisms( broad/multi/unicast) </li></ul></ul></ul><ul><ul><ul><li>Packet characteristics (frame sizes and direction) </li></ul></ul></ul><ul><ul><ul><li>Routable and non-routable services (IP, NETBIOS) </li></ul></ul></ul><ul><li>Undefined applications allow choice of distribution balance </li></ul>
  25. 25. Capacity Planning – Step 4 <ul><li>Baseline existing network </li></ul><ul><ul><li>Baselining – a behavioural profile of the network obtained from </li></ul></ul><ul><ul><ul><li>Packet traces, transaction rates, event logs and stats </li></ul></ul></ul><ul><ul><ul><li>Router ACLs(access control list ), firewall rulebases </li></ul></ul></ul><ul><ul><ul><li>Inventory of hardware and software revisions </li></ul></ul></ul><ul><ul><li>Traffic profiles -Capture data for a stable working network with details of </li></ul></ul><ul><ul><ul><li>bandwidth utilization by packet type and protocol </li></ul></ul></ul><ul><ul><ul><li>Packet/frame size distribution </li></ul></ul></ul><ul><ul><ul><li>Background error rates </li></ul></ul></ul><ul><ul><ul><li>Collision rates </li></ul></ul></ul><ul><ul><li>Various tools can be used </li></ul></ul><ul><ul><ul><li>Network and protocol analysers, SNMP data, RMON probes, OS tools, traceroute, ping etc </li></ul></ul></ul>
  26. 26. Capacity Planning – Step 5 <ul><li>Make traffic projections using some, or all of: </li></ul><ul><ul><li>Hand calculation </li></ul></ul><ul><ul><li>Commercial analytical tools to project network utilisation </li></ul></ul><ul><ul><li>Simulation tools (most detail) </li></ul></ul>
  27. 27. Capacity Planning – Step 6 <ul><li>Summarize input data for design process </li></ul><ul><ul><li>Budget </li></ul></ul><ul><ul><li>Database of sites, user populations, </li></ul></ul><ul><ul><li>List of key applications and their behaviour </li></ul></ul><ul><ul><li>Traffic matrix </li></ul></ul><ul><li>Need to consider </li></ul><ul><ul><li>Static or dynamic bandwidth allocation </li></ul></ul><ul><ul><li>Max. Delay and Max. hops between sites </li></ul></ul><ul><ul><li>Resilience, Availability, degree of meshing </li></ul></ul><ul><ul><li>Design constraints and trade-off </li></ul></ul><ul><ul><ul><li>(e.g. delay v cost) </li></ul></ul></ul>
  28. 28. The building-block design process (an alternative)
  29. 29. Summary <ul><li>Good design </li></ul><ul><ul><li>Is an iterative process of continuous refinement </li></ul></ul><ul><ul><li>Is logical and consistent </li></ul></ul><ul><ul><li>Should deliver acceptable performance and cost metrics (trade-off) </li></ul></ul><ul><ul><li>Is more than choosing the technology! </li></ul></ul>