Watch Computer Networks Crash Course.

Introduction to Computer Networks

• The internet has revolutionized the way we communicate and access information
• 150 years ago, sending a letter from London to California took 2-3 weeks, but today an email takes a fraction of a second

Early Computer Networks

• The first computer networks appeared in the 1950s and 60s
• They were used within organizations to facilitate the exchange of information and share physical resources
• These early networks were called Local Area Networks (LANs)

Ethernet

• Developed in the early 1970s at Xerox PARC
• Still widely used today
• Uses a shared ethernet cable to connect computers
• Each computer has a unique Media Access Control (MAC) address
• Uses Carrier Sense Multiple Access (CSMA) to manage data transmission

CSMA and Collisions

• When multiple computers try to transmit data at the same time, it causes a collision
• To solve this, computers use Exponential Backoff, which involves waiting for a random period of time before re-transmitting

Network Switches and Collision Domains

• To reduce collisions and improve efficiency, networks can be broken into smaller collision domains using network switches
• Switches keep a list of MAC addresses and only pass data between networks if necessary

Routing

• There are two approaches to routing: Circuit Switching and Message Switching
• Circuit Switching allocates a dedicated communication line for exclusive use
• Message Switching passes messages through multiple stops, using a table to determine where to send the message next

Packet Switching

• Chops up big transmissions into small packets with destination addresses
• Packets are routed through the network using flexible routes with spare capacity
• This approach is decentralized and fault-tolerant
• The internet runs on Packet Switching today

ARPANET and the Internet

• The first packet-switched network was ARPANET, developed in the 1970s
• Today, the internet is a global network of interconnected routers and computers
• It continues to grow rapidly, especially with the advent of IoT devices

Watch Highest Paying Information Technology Careers video.

• The first career is Technology Sales, an entry-level job that can be accessed quickly without a college degree or previous experience.
  • Business Development Representative is an entry-level career in technology sales.
  • According to Glassdoor, technology sales make approximately $109,000 per year.
  • On LinkedIn, there are 85,000 results for entry-level technology sales jobs.
  • With experience, technology sales professionals can earn over $220,000 and even over $540,000 per year.
• The second career is Information Security Engineer, which requires at least five years of cybersecurity experience.
  • Information Security Engineers oversee an organization’s IT security.
  • According to Glassdoor, Information Security Engineers make about $117,000 per year.
  • On LinkedIn, there are 17,000 results for entry-level Information Security Engineer jobs.
• The third career is DevOps Engineer, a type of software engineer specializing in getting products to market as fast and efficiently as possible.
  • According to Glassdoor, DevOps Engineers make about $131,000 per year.
  • On LinkedIn, there are 25,000 results for entry-level DevOps Engineer jobs.
• The fourth career is Software Development Manager, a position that combines software development skills with management skills.
  • According to Glassdoor, Software Development Managers make about $213,000 per year.
  • On LinkedIn, there are over 8,900 results for Software Development Manager jobs.
• The fifth career is any executive position other than CEO, such as a Chief Technology Officer (CTO) or a Chief Information Officer (CIO).
  • According to Glassdoor, CIOs make $298,000 per year.
• The sixth career is a Marketing or Sales Director, a high-level position in a company.
  • According to various sources, Marketing or Sales Directors make between $184,000 and $221,000 per year.
• The seventh career is a Tech CEO, which can result in making a ridiculous amount of money, especially in a startup.
  • Tech CEOs have more opportunities than CEOs in other industries.
  • For instance, Chad Richison of Paycom made $211 million a few years ago, and Elon Musk made $6 billion in money and his net worth increased by $110 billion one year and $90 billion the next year.

LEARNING TARGETS:

• I understand the benefits of computer networks and the concept of Local Area Networks (LANs).
• I can discuss the highest paying Information Technology careers from 2023.