IS516 Computer Communication and Networks Lecture 07

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IS516 ?????????????????????????????????
(Computer Communication and Networks)
Lecture 07 ???????????????????????????????
??

• ??.????????? ????????

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???????????????????? (???? Mid-term)
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Design Activities

• The design activity is truly an in-depth
  process, which includes

• ????????????????????????????????????????

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• ?????????????????????????????????????????????

• ????????????????????????????????????????????????
  ???
• ??????? 1, 2 ??? 3 ??????????????????????????

• ??????????????????????????????????? physical
  ???
• logical

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LAN Design Goals

• Functionality ?????????????????????????????????
  ????????????????????????????????

• Scalability ???????????????????????????????????
  ????????????????????????????????

• Adaptability ??????????????????????????????????
  ???????????????? ?????????????????????????????????
  ??????????????????????????????????????????????????
  ????

• Manageability ?????????????????????????????????
  ??????????????????????

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Design Methodology

• ???????????????????? - Analyze requirements
• ??????????????????????????????? - Develop LAN
  structure (topology)
• ??????????????????????? - Set up addressing (and
  naming conventions) and routing

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Analyze Network and User Requirements

• ????????????????? - Business issues
• ???????????????? - Technology issues
• ???????????????????? - Administrative issues
• ??????????????? - Gather Data (corporate
  structure, business information flow, application
  in use, current topology, etc.)
• ???????????????????? - Business requirements
• ???????????????????? - Technical requirements
• ??????????????????????????????????? -
  Applications or business operations
• ?????????????????????????????? - Availability
  requirements (throughput, response time, access
  to resource)

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Analyze Network Load Requirements

• ??????????????????????????????????????
• ???????????? Client/Server
• ???????????? Host/terminal
• ????????????????????? (Routing protocols)
• ????????????????????????????????? ?????????backup
  
• ??????? worst-case traffic load
  ??????????????????????????????????????????????????
  ???????????????????????????

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Develop LAN Topology

• ??????????????????????????????????????????????
• ???????????????
• Star Topology
• Extended Star Topology

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Ethernet Technology

• Segmentation
• Bridge ??? switch ?????????? segmentation
• ???????????????????? collision domains
• ????????? single broadcast domain
• Collision domain (bandwidth domain)
• Repeaters ??? hubs ???????????? collisions ????
  switches, bridges ??? routers ???
• Broadcast domain
• ?????????????????????????????? frames
  ????????????????????????????????????????
• Broadcast domains ???????????????????? routers
  ????? routers ????????? broadcast frames ???

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Network Design

• ?????????????????????????????????????????
  ??????????? 3 ????????? OSI model

• Layer 1 - Physical Layer?????????????????????????
  ?????? ???? CAT5 UTP ??? fiber-optic cable
  ??????????????? EIA/TIA 568 ??????????????????????
  ?????

• Layer 2 - Data Link Layer?????????????
  ?????????????????????????? Layer 2 ???? bridges
  ???? LAN switches ???????????????????????????????
  ? Layer 1 ??????? LAN segment ????????????????????
  ??????????????????????????? collision and
  broadcast domains.

• Layer 3 - Network Layer ?????????????????????????
  ??????????????????????? layer 3 ???? routers
  ????????????????? unique LAN segments and
  ?????????????????????????? segments ????
  ????????? layer 3 ???? IP address

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Design Goals

• Physical Layer
• Design Goal
• ??????????????????????????????????????????????????
  ???????????
• Data Link Layer
• Design Goals
• ?????????????????????? MDFs or IDFs ???? end host
  ??????????????? Layer 1 ?????????? physical LAN
  segment
• ??????? LAN switch ??????? microsegmentation
  ?????????????? collision domain
• ?????????????????? (??? Layer 2)
  ?????????????????????????????????????????????
  virtual workgroups (VLANs) ??? unique broadcast
  domains.
• Network Layer
• Design Goals
• ?????????????????????????? LAN segments
  ??????????????????? data packets
• ??? ARP protocol
• ??? collisions ??????? segments.
• ???????????? Layer 4 ??????? segments

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Cable Types and Wiring Configurations

• Copper
• Coaxial
• Twisted pair
• Fiber-optic
• Multimode
• Single-mode
• Wiring configurations
• Star/Extended Star
• Distance limitations

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Extended Star Topology

• ??????????????? EIA/TIA
• ????????????????????????????????????? (Catchment
  areas ) ?????????????????????? ???????????????????
  ? vertical cabling
• Vertical cabling ????????????????? MDF
  ?????????? single LAN segment

Vertical cabling - (Backbone cabling)
??????????????????????????????? wiring closets,
wiring closets ??? POP, ?????????? buildings
??????????????????? LAN ????????
Catchment areas ????????????????????????????????
?????????????????????????? ???? hub.
IDF - Intermediate Distribution Facility.
????????????????????????????????????????????????
star ???IDF ????????????? MDF.
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Layer 2 - LAN Switching

• ??????????????????????????????? Layer 2 (Data
  Link Layer) ??????????????????????????????
  ????????????????????????????????????
  ???????????????? Layer 2 ?????????????????????
  (??????????? NIC ??????? host ?????????????????)
  ??? Bridges ??? LAN switches
• LAN switches (Layer 2 Switch) ????????????
  bandwidth ????????? port ?????????????
  ????????????? bandwidth ?????????? vertical
  cabling, uplinks and servers ???

The theoretical maximum bandwidth for a Layer 2
Switch (No-of-ports Bandwidth)/2
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MDF-Main Distribution Facility

• MDF - Main Distribution Facility.
  ?????????????????????????????????
  ?????????????????????????????????? star ??????
  patch panels, hub, and router
• ???????????????????? simple star
  ????????????????????????????? main distribution
  facility (MDF) ????????????????????? horizontal
  cross connect (HCC) patch panels.
• HCC patch cables ??????????????????? Layer 1
  'horizontal cabling' ??? Layer 1 ???LAN switch
  ports ??? Layer 2
• uplink port ??? LAN switch ??????????????
  Ethernet port ??? router (Layer 3 ) ?????? 'patch
  cable'. ? ?????? end host ???????????? router
  port
• ????????? horizontal cable ???????????????????(???
  ???????) ??? HCC patch panels ????????????????????
  ?????????????

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Use Switches to reduce congestion

• ?????????????????????????????????????????????????m
  icrosegmentation ?????????? collision domains
• Cascade switches and hubs
• ????????????????? ????????????????????????????????
  

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Microsegmentation

• ????????????????????????????? ????????????????????
  ??????????????? bandwidth ????????????????????????
  ??
• ?????????? LAN switching ??? MDF ??? IDFs
  ?????????????????????????????? collision domains
  ??? ????????????????????????? horizontal cable
  ??? vertical cable. ????????? vertical cable
  ????????? data traffic ?????????????? MDF ???
  IDFs ???????????????????????????????

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Collision Domains

• ???????????????????????? switch
  ?????????????????????????? LAN ??????? collision
  domain ?????????? 2 host ???????? ???????? hubs
  ??????? collision domain ?????????????? bandwidth
  ???????????????.
• Shared LAN hub ??? multiport repeater
  ?????????????? collision domain. Hosts
  ?????????????????????? shared LAN hub ????
  collision domain and the bandwidth ???????

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Layer 3 - Routing

• ???????????? Layer 3 (Network Layer) ???? routers
  ??????????????? segmentation ??? LAN ???????
  unique networks ???? physical and logical.
• Routers ?????????????????????????????? wide area
  networks (WANS) ???? Internet ???

• Routers serve as broadcast firewalls
• Routers consolidate for scalable internetworks
• Network protocol addressing and routing provides
• built-in scaling

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Documenting Your Network

• ????????????????
• Physical Network Maps (cutsheet)
• Logical Network Map (IP addressing scheme)
• Addressing Maps (snapshot view of network)

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Reasons to Document

• ??????????????????????????????????
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  ????????????
• ??????????????????????????????????????????????????
  ????????????
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?????????????????????????????

• ??????????????????????????????????????????????????
  
• ???????????????????????? Bandwidth
• ????????????????????????????? layer 1, 2,??? 3
  ??????????????????????????????????????? ??????
  cable, hub, bridge, switch, router ???
• ????????????????????????????? ????
  ????????????????????????
• ??????????????????????? ??????????????????????
• ???????????????????????????????????
  ??????????????

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