CISCO

Computer Networking

The Internet

The Internet Yesterday

Basics of Computing

Parts of a Computer CPU - Central Processing Unit Memory - ROM, RAM, etc. Interface - Modem, Video Card, Floppy, etc. All are connected by a bus which is plug in slots.

NIC Network Interface Card PCs use IDE or PCI Laptops use PCMCIA (“credit card”) TCP/IP - the computers address on the network

Networks - a “conglomeration” of people or things focused on a common goal LAN Local Area Network used within or between offices WAN Wide Area Network used between buildings or within a “complex”

How is information stored in computers? By using the binary number system The only possible symbols or "bits", are 1 and 0. The bits represent text, pictures, and sounds A 1 bit is often represented by the presence of voltage on a copper conducting cable or light in an optical fiber

Imagine measuring the voltage at one point on the cable as time goes on (for a fiber, imagine measuring the light intensity versus time). Your measurements would allow you to create a graph of voltage versus time (for a fiber, light intensity versus time).

The numbering system most frequently used is the decimal numbering system. A decimal numbering system is based on powers of 10: 100, 101, 102, 103, 104, etc. 100 = 1 101 = 10 X 1 or 10 102 = 10 X 10 or 100 103 = 10 X 10 X 10, or 1000 104 = ?????????

When counting in the decimal system when you reach the number 9 you must add another digit. Examples: Count 9, 10 Count 99, 100 Count 999, 1000

Binary numbering system (Bit - binary digit) How does a binary number system differ from a decimal numbering system? A binary numbering system is based on powers of 2 20, 21, 22, 23, 24, etc. 20 = 1 21 = 2 X 1 or 2 22 = 2 X 2 or 4 23 = 2 X 2 X 2, or 8 24 = ?????????

Let’s count in binary. Remember you can only use 0s and 1s. 1 10 11 100 101 110 111

Bonus: What would an octet of all ones equal? Let’s take a break and complete a worksheet on converting decimal to binary and vice versa. Bonus: What would an octet of all ones equal?

American Standard Computer Information Interchange

Bandwidth Water Hiway System Radio Audio Media Coaxial Cable Category 5 Cable (Cat 5) Fiber Optic Bandwidth determines throughput (because file are transferred faster) slow or fast 14.4K or 56K