Topic 08 _ 09

Page 1: Network Layer

• Internet Protocol : Core protocol used for routing data across networks.

Page 2: TCP/IP Model Overview

• Application Layer:

  • Manages application data and session handling.

  • Protocols: HTTP, SMTP, FTP, DNS.

• Transport Layer:

  • Processes connectivity using port numbers.

  • Supports multiplexing and demultiplexing.

  • Protocols: TCP, UDP.

Page 3: TCP/IP Model Network Layer

• Network Layer:

  • Handles end-to-end connectivity through IP addressing.

  • Implements fragmentation and defragmentation for data packets.

  • Takes care of error checking and correction.

  • Supports tunneling.

  • Protocols: IPv4, IPv6.

Page 4: TCP/IP Model Datalink & Physical Layers

• Datalink Layer:

  • Facilitates hop-to-hop connectivity with MAC addressing.

  • Provides error checking and correction.

  • Protocols: Ethernet (IEEE 802.3), WiFi (IEEE 802.11).

  • Involves framing and media access control (MAC).

• Physical Layer:

  • Handles actual data transmission over physical media.

  • No addressing is involved.

  • Involves encoding and decoding of data.

Page 5 to 7: Network Layer Functionality

• Figures:

  • Illustrations depict network layer operations:

    • Figure 20.2 shows network layer function in an internetwork.

    • Figure 20.3 details network layer activities at source, router, and destination illustrating routing tables and IP packet processing.

Page 8: Switching at Network Layer

• Note:

  • Switching uses the datagram approach for packet-switched networks.

Page 9: Communication at Network Layer

• Note:

  • Network layer communication is connectionless.

Pages 10 to 12: IPv4 Overview

• IPv4:

  • Core delivery mechanism of TCP/IP protocols.

  • Features include datagram, fragmentation, checksum.

  • Structure consists of header and data, varying from 20 to 65,536 bytes.

Pages 13 to 15: IPv4 Service Types & Length

• Service Type:

  • Differentiates services based on delay, throughput, reliability, and cost.

• Length Field:

  • Total length field defines entire datagram length including the header.

Pages 16 to 19: Data Encapsulation and MTU

• Encapsulation:

  • Shows how data is encapsulated in Ethernet frame.

• MTU:

  • Maximum Transfer Unit: Optimal size of data encapsulated in a frame.

Page 20: Fragmentation Flags

• Flags:

  • Flags used include 'D' (Do not fragment), 'M' (More fragments).

Pages 21 to 22: Fragmentation Examples

• Examples:

  • Detailed diagrams illustrate fragmentation of data packets, showcasing offset values for fragments.

Pages 23 to 24: IPv4 Options and IPv6 Datagrams

• IPv4 Options:

  • Various options such as operation, recording route, and timestamps.

• IPv6 Datagram:

  • Structure includes base header and optional extension headers.

Page 25: IPv6 Datagram Format

• Components:

  • Party includes version, priority, flow label, payload length, and addresses.

Page 26: Next Header Codes for IPv6

• Codes:

  • List of next header codes used in IPv6 with corresponding protocols (ICMP, TCP, UDP, etc.).

Pages 27 to 28: Congestion Control Priorities

• Table of Priorities:

  • Defines meaning and categories for congestion-controlled and noncongestion-controlled traffic.

Page 29: Comparison of IPv4 and IPv6 Headers

• Differences:

  • Key differences in header structure and fields between IPv4 and IPv6, emphasizing removal and replacement of certain fields.

Pages 30 to 31: IPv4 Options vs. IPv6 Extension Headers

• Comparison:

  • Lists transitions from IPv4 options to IPv6 extension headers, indicating new and eliminated features.

Page 32: Transition from IPv4 to IPv6

• Overview:

  • Transition process is gradual to prevent issues.

  • Strategies include dual stack, tunneling, and header translation.

Pages 33 to 37: Transition Strategies Illustrated

• Figures:

  • Visual representations of transition strategies (dual stack, tunneling, header translation) detailing their operational mechanisms.

• Table:

  • Header translation steps outlined to convert IPv6 addresses to IPv4 using specific procedure.