Computer Networks chapters
  1. 01Reference Models & Network Layers
  2. 02Data Link Layer & MAC Protocols
  3. 03Network Layer & IP Addressing
  4. 04Transport Layer (TCP & UDP)
  5. 05Application Layer Protocols & Security

Chapter 2 · CN

Data Link Layer & MAC Protocols

4 topics in 2 parts

Key ideas

7. Application Layer (HTTP, DNS, SMTP, FTP) — Data Payload 6. Presentation Layer (SSL/TLS Encryption, Compression, MIME) 5. Session Layer (RPC, NetBIOS, Session Checkpointing) 4. Transport Layer (TCP, UDP) — Segments & Port Addressing 3. Network Layer (IPv4, IPv6, ICMP, Routers) — Packets & IP Addresses 2. Data Link Layer (Ethernet, Switches, MAC) — Frames & Error Checking (CRC) 1. Physical Layer (Cables, Fiber, Radio Waves, Hubs) — Raw Bit Streams (0/1)
Data Link Layer & MAC Protocols
Network ParameterTCP / Connection-OrientedUDP / Connectionless
ReliabilityGuaranteed delivery with ACK & retransmissionBest-effort delivery (packets may drop)
Connection State3-Way Handshake (SYN, SYN-ACK, ACK)No handshake; immediate datagram dispatch
Header Overhead20–60 bytes (sequence numbers, flags)8 bytes fixed header
Target Use CasesHTTP/HTTPS, SSH, File Transfer (FTP)Live Video Streaming, VoIP, DNS, Gaming

All 4 topics in Data Link Layer & MAC Protocols

  1. Data Link

    • Error Detection & CRC
    • Sliding Window ARQ Protocols

  2. MAC Sublayer

    • ALOHA Protocols
    • CSMA/CD & CSMA/CA