Figure 5-1 Encapsulation L1 Physical L3 Network L5 Session L7 Applications L2 Data Link L4 Transport L6 Presentation SourceDestination Data Data Stream Network Header Data Data Stream Frame Header Frame Trailer L1 Physical L3 Network L5 Session L7 Applications L2 Data Link L4 Transport L6 Presentation L = Layer - as L1 = layer 1

Figure 5-2 Data Encapsulation Process Data Data Stream Network Header Data Frame Header Frame Trailer Data Segment Packet Frame Bits being Composed Layer 4 Layer 3 Layer 2 Layer 1 Layer 5

Figure 5-3 OSI and TCP/IP models compared Layer 6 Presentation Layer 3 Network Layer 1 Physical Layer 2 Data Link Layer 4 Transport Layer 5 Session Layer 7 Application Link Network Transport Application OSI Model TCP/IP Model

Figure 5-4 An example of a peer-to-peer network

Figure 5-5 An example of a client/cerver network Server Client

Figure 6 - Star Topology Workstation Server Controller

Figure 5-7 A Bus Topology Server Printer workstation Computer

Figure 8- Ring Topology Workstation Server

Figure 5-9 A CSMA/CD collision A B A B A B A B Clear to send collisio n Sending Wait random time 1234

Figure 5-10 Collision Domain Collision Domain 1 Collision Domain 2 or Router Switch Bridge

Figure 5-11 Modular Jack and Active Hub RJ45 Active Hub

Figure 5-12 A network segment built on a 10 Mbps hub 2 Mbps 10 Mbps 2 Mbps

Figure 5-13 Bridging Two Network Segments A D CB EF 01-3A-2D-6C-0C-2A D-7C-DC A2-1D-75-B B-0D-7C-1F-3D D-7C-01-BC Segment 1 Segment D-7C-01-9A Bridge

Figure 5-14 An Example of a Switched Ethernet Configuration E D C A B Server Ethernet Switch Workstation 100 Mbps

Figure 5-15 A VLAN environment D Internet or WAN Accounting Marketing Engineering Server Farm

Figure 5-16 Point-to-Point and Multipoint (daisy-chained)

Figure 5-17 X.25 Pack Switched Network A4 th (longest path)A D3 rd D C1 st (shortest path)C B2 nd B Re-Ordered and delivered to computer “Z” Packet Arrives at “9” Path Taken Packets: A, B, C, and D Leave Computer “Y” via“1” Computer “Y” Computer “Z”

Figure 5-18 Statistical Pack switching Virtual Circuit B A C AA AA AAA CCCCC CCBBBBBBBB Packet Switch Data Flow Time Division Multiplexing

Figure 5-19 Combining different services onto a single access channel Multiplexed cell stream B A C AA AA AAA CCCCC CCBBBBBBBB ATM Multiplexer Data Flow Voice Video Data

Figure 5-22 PVCs in a Frame Relay network LAPD SP LAPD SP SP = Switch Point PVC = DTE or FRAD =

Figure 5-21 Frame Relay frame format (LAPD)

Figure 5-22 Frame Relay bandwidth-on-demand

Collision Domain

Figure 5-12 A Combination of interconnections

Figure 5-13 Three Tiered Network Hierarchy

Figure 5-17Data Service Components

Figure 5-17 DDS Components DTE CSU/DSU DDS Hub Physical interface V.35 Data Access Lines Physical interface V.35 Long-distance digital channel

Figure 5-18 Pack switching PS Terminal SDLC Host X.25 Host RJE Station Asynch Terminal Terminal PS = Packet Switch

Figure 5-1The OSI model versus the TCP stack Figure 5-2An example of a shared-medium LAN Figure 5-3An example of Gigabit Ethernet Figure 5-4Token passing Figure 5-5CSMA/CD Figure 5-6Collision Domains Figure 5-7RJ45 modular jack and Active Hub Figure 5-8shows a network that uses a combination of interconnection Figure 5-9Bridging two network segments Figure 5-10An example of a switched Ethernet configuration Figure 5-11An Ethernet switch Figure 5-12A VLAN Figure 5-13A three layer network hierarchy Figure 5-14Data service components Figure 5-15Point to Point leased line and multipoint (daisy chained) Figure 5-16DDS components Figure 5-17Packet switching Figure 5-18Statistical Packet Switching Figure 5-19An X.25 packet-switched network Figure 5-20Frame Relay frame format (LAP D) Figure 5-21PVCs in a Frame Relay network Figure 5-22Frame Relay bandwidth-an-demand Figure 5-23Combining different services onto a single access channel