Chapter 6 Networks and Telecommunications The Strategic Management of Information echnology
Chapter 6 Networks and Telecommunications The Strategic Management of Information Technology
Transaction Processing System Input Process Output Systems Development Communication Information
Transaction Processing System Input Process Output Information Communication Systems Development
Local Area networks
Local Area Networks
Local Area networks A Definition Provides access to shared resources such as printers, data, and applications Increases controllability and consistency in applications and data Increases access to shared applications and databases in large computers with many users Provides a vehicle for electronic mail Shares access to external resources through communication lines
Local Area Networks: A Definition Provides access to shared resources such as printers, data, and applications Increases controllability and consistency in applications and data Increases access to shared applications and databases in large computers with many users Provides a vehicle for electronic mail Shares access to external resources through communication lines
Local Area networks Reason Performance Change Management Systems Management Network Management Direct communication Ease in Installation and maintenance
Local Area Networks: Reason Performance Change Management Systems Management Network Management Direct Communication Ease in Installation and Maintenance
Network protocols 1. Physical Layer Interfaces between Network medium and network drives Defines electrical and mechanical characteristics of network Bad Plug
Network Protocols 1. Physical Layer – Interfaces between Network Medium and Network Drives – Defines Electrical and Mechanical Characteristics of Network – Bad Plug
Network protocols 2. Logical Link Layer Frames Packets Controls Physical layer data flow Data collision 3. Network Layer Addresses and Routes Packets Handles fragmentation and reassembly of data Broadcast storm 4. Transport Layer Manages Network Layer Connections Provides Reliable Packet Delivery Mechanism Multiple ACKs
Network Protocols 2. Logical Link Layer – Frames Packets – Controls Physical Layer Data Flow – Data Collision 3. Network Layer – Addresses and Routes Packets – Handles Fragmentation and Reassembly of Data – Broadcast Storm 4. Transport Layer – Manages Network Layer Connections – Provides Reliable Packet Delivery Mechanism – Multiple ACKS
Network protocols 5. Session Layer Provides Remote Procedure Call Support Reports Lower-Layer Errors Protocol error 6. Presentation Layer Specifies Architecture-Independent data transfer Format Encodes and Decodes Data; Encrypts and Decrypts Data Compresses Data Misdirected data 7. Application Layer Provides Interface to End-User Processes Provides Standardized Services to Applications Incompatible Software
Network Protocols 5. Session Layer – Provides Remote Procedure Call Support – Reports Lower-Layer Errors – Protocol Error 6. Presentation Layer – Specifies Architecture-Independent Data Transfer Format – Encodes and Decodes Data; Encrypts and Decrypts Data; Compresses Data – Misdirected Data 7. Application Layer – Provides Interface to End-User Processes – Provides Standardized Services to Applications – Incompatible Software
Communication according to the Open System Interconnection Reference Model Application Layer 76543 Presentation Layer Session layer Transport layer Network layer Data Link layer Physical layer
Communication according to the Open System Interconnection Reference Model 1 2 3 4 5 6 7 Application Layer Presentation Layer Session Layer Transport Layer Network Layer Data Link Layer Physical Layer
Physical Layer Hardware Description The interface to the physical cable medium 76543 described: layout of connectors, signals on each connector, voltage levels The physical connection to the netw connections are established and maintained and howlerror conditions in data medium are handed Physical layer
Physical Layer 1 2 3 4 5 6 7 Physical Layer Hardware Description: The interface to the physical cable medium is described; layout of connectors, signals on each connector, voltage levels. The physical connection to the network, how connections are established and maintained, and how error conditions in data medium are handled