lecture25: Coding with Noise

Topics covered

• Redundancy is your friend
• It has problems
• Error Detection and Correction
• Error Detection
• Parity Bits
• Parity Bits and Errors
• Parity Bits Example
• Checksums
• Examples
• CRCs
• Assignment
• Hash Functions
• Hash Function Example: MD5
• Retransmission
• A Brief Introduction to the Stack
• Layered protocols: OSI model
• Encapsulation
• Layer 1: Physical layer
• Layer 2: Data-link layer
• Layer 3: Network layer
• Layer 4: Transport layer
• Layer 5: Session layer
• Layer 6: Presentation layer
• Layer 7: Application layer
• Post office analogy
• TCP/IP has 5 ``layers''
• TCP/IP Encapsulation
• IP header
• TCP header
• TCP/IP operation
• Narrow Waist of IP: hourglass
• Broken layering
• What's best?