1. Telecommunications and Networking

2. Basic concepts Communication protocols (TCP/IP)
Data transmission methods
Asynchronous
Synchronous
Connecting
Modem and TCU
Hardwired and remote
Data transmission channels (bps)
narrow bands: 5-30
voice bands: 1,000-9,600
broad bands: 100,000
Types of communication lines
simplex
half-duplex
duplex

3. Networks Concept Network topology Local-area networks
"a group of interconnected computers, workstations, or computer devices (such as printers and data storage systems).”
Network topology
bus
star
ring
Local-area networks
bus: Ethernet, carrier sense multiple access (CSMA)
ring: token passing method
Distributed data processing
"interconnects sites of one organization not only for communication of data and messages but also for the sharing of resources."

4. Distributed data processing
TSS - Time Sharing Systems PC PC PC PC
MAINFRAME
CSS - Client Server Systems

5. CSS architecture

6. EDI Concepts EDI is a mechanism for electronic trading
EDI replaces paper flow with online transactions
EDI architecture > see next slide
EDI is for trading partners
Implementation plan is a key factor
Obstacles:
lack of transaction standardization
high start-up costs
EDI third-party suppliers
AT&T, Control Data, EDS, GE, Western Union, IBM, Martin Marietta Data Systems, etc.

7. EDI architecture

8. Basic Communications Model Standards are needed at all Layers
User Layer
Application Layer
Computer (Transport) Layer
Transmission Layer

9. Layering in Major Architectures
Basic Model
TCP/IP
IPX/SPX
OSI
Application
Computer
(Transport)
Internet
Subnet
(OSI)
Application (7)
Presentation (6)
Session (5)
Transport (4)
Network (3):
Internet &
Data Link (2)
Transport:
TCP, etc.
Complex:
SPX, etc.
Physical (1)