Computer Networks: A Deep Dive
1. Company Network Needs
- Marketing: Negative impact.
- Banking: Control finances remotely. Positive impact.
- Competition Monitoring: Positive impact.
- Framework Expansion: Positive impact.
- Communication: Sending and receiving requests. Positive impact.
- Social Interaction: Reduced face-to-face contact. Negative impact.
- Productivity and Costs: Increased productivity and cost savings. Positive impact.
- Network Printing: Shared printing resources. Positive impact.
- Network Setup: Requires a well-maintained network. Negative impact.
- Document Sharing: Efficient document transfer. Positive impact.
2. History of Networks
- 1940s: Large, error-prone electromechanical computers.
- 1947: Invention of the transistor, leading to smaller, more reliable computers.
- 1950s: Mainframe computers with punch card programs became common in large institutions.
- Late 1950s: Creation of the integrated circuit.
- 1960s: Mainframe terminals and integrated circuits became widespread. Minicomputers were invented.
- 1977: Apple Computer Company introduced the microcomputer (personal computer).
- 1981: IBM released its first personal computer.
- 1980s: Users began using modems to connect computers and share files.
- DoD Network: The U.S. Department of Defense developed wide area networks (WANs), which eventually led to the internet.
3. Internet Connections
The internet can be divided into three connection types:
- Physical Modem Connection
- Logical TCP/IP Connection
- Application to Browser Connection
4. Weblogs
A weblog (blog) is a website with entries published through a simple publishing system.
5. Podcasting
Podcasting allows recording internet radio or audio programs. These recordings can be downloaded to a portable player (e.g., iPod) or listened to directly from a computer.
6. Transmission vs. Communication
Transmission involves carrying signals, while communication involves carrying signals using a common code between transmitter and receiver.
7. Terminal Types
- Simple: No autonomy, controlled externally.
- Smart: Some processing capability with its own processor and memory.
- Programmable: Tasks assigned by loading external programs.
8. Transmission Modes
- Synchronous vs. Asynchronous: Synchronous transmission involves both computers sending data simultaneously, while asynchronous transmission uses codes to indicate data boundaries.
- Serial vs. Parallel: Serial transmission sends data sequentially over a single line, while parallel transmission sends groups of bits simultaneously over multiple lines.
- Analog vs. Digital: Analog transmission uses a continuous range of values, while digital transmission uses discrete values (0 and 1).
9. Modulation
Modulation ensures efficient data transfer by using optimal frequencies and transforming signals.
10. Private vs. Public Lines
- Private Line: Owned and controlled by a single entity.
- Public Line: Owned by telephone companies and shared by multiple users.
11. Switched vs. Dedicated Lines
- Switched Lines: Shared public lines used by many users.
- Dedicated Lines: Exclusively used by two users or specific equipment.
12. CMT Functions
- Arbitration between operators
- Control of public service obligations
- Numbering assignment to operators
- Ensuring open competition
- Rate proposals
- Monitoring interconnection prices in public networks
- Exercising sanctioning authority
- Coordination with the Tribunal de Defensa de la Competencia en España