• Motivation: exploring the network that you use every day... terms, how each protocol works, become a smarter user of networking
  
• Class discussion: Survey of Internet Applications that the class commonly uses:
  
  • Instant messaging
    
  • Music downloading
    
  • Multi-user network Games:
    
  • Web surfing, email:
    
  • Less common: skype, voip
• Course Operations: homework & programming assignments, "engaging finds" (see handout), exams, attendance
  
• How to interpret the text's figures that depict today's networks, Introductory terminology of basic components: end systems, core systems (routers), protocols
  

• REVIEW: Design a protocol for a link that may lose a message
• SWITCHING
• Circuit Switching (for the traditional digital telephone network) works well for what kind of data?
• Packet Switching, which is most effective with what kind of data
• How do each of these switching techniques support multiple concurrent sources over one "wire"? i.e. Multiplexing. Compare the 3 basic strategies...
• Pipelining packets
• DELAY COMPONENTS & PACKET LOSS
• Definitions, motivations, Applets, and your first "network tool"
• Time-space diagrams of the impact

Public key cryptography, RSA algorithm, authentication protocols.

• State stored at the server
• Non-persistent connection, vs Persistent connection

• Continued discussion on HTTP:
  • How to maintain server-state in a stateless protocol
• The File Transfer Protocol (FTP):
  • Highlights: Control is out-of-band with Data.
  • Analyze it's Application Layer Protocol features

Electronic Mail

• Major components: agents, servers, protocol
• The SMTP protocol
  • Comparison with HTTP
  • A "push" protocol
  • Mail message format
  • MIME extension for non-ASCII data
• Mail access protocols
  • Post Office Protocol, ver 3 (POP3)
  • Internet Mail Access Protocol (IMAP)

DNS: Domain Name System

• Services provided by DNS
• Why the original solution with a "flat" structure doesn't work
• Distributed, hierarchical database that exploits naming structure
• Root, top-Level domain (TLD), authoritative and local DNS servers
• Recursive and iterative querying methods

• Content Distribution Networks, continued
• "push" caching
• Example scenario connecting from a UT laptop
• Web caching
• "pull" caching
• transparent web cache via intermediate host
• concepts: hits, misses, what's cacheable?
• impact on delay due to a near-by cache 
• Socket programming
• Motivation, definitions (e.g. socket)
• Network API (in general)
  
• Socket programming with the java.net API

• Digital Signatures
• not possible with symmetric keys
• Hash Function Algorithms
• Trusted Intermediaries
• Key Distribution Centers (KDCs)
• Certification Authorities

• Firewalls
• Packet filtering
• Application gateway
• Attacks and counter-measures
• Packet sniffing, spoofing, denial of service etc. 
• Secure Sockets Layer (SSL) 
• Transport Layer Security (TLS)

• Security wrap-up
• Secure Sockets Lyer (SSL)
• Firewalls
• Transport Layer Principles
• Services for the next layer up
• TRANSPORT LAYER multiplexing and DEMULTIPLEXING
• Connectionless and connection-oriented

• User datagram protocol (UDP)
• Applications of UDP
• Error-detection (checksum)
• Reliable data transfer
• Motivation for each component of reliable data transfer protocols
• Alternating Bit protocol
  

• Reliable data transfer continued
• Sliding window protocol
• with FIFO channels
  
• with lossy FIFO channels
  
• with LRD channels
• Go-Back-N protocol
• receiver buffer size = 1
• Selective repeat ACK scheme

• TCP Congestion Control
• Additive increase, multiplicative decrease
• Slow start 
• Network Layer
• Forwarding vs. routing
• Service models
• IP fragmentation and reassembly

• IPv4 Addressing
• Hierarchical addressing
• Network Address Translation
• Dynamic Host Configuration Protocol (DHCP)
• Internet Control Message Protocol (ICMP)
  
  

• Routing Algorithms
• Dijkstra's Algorithm
• Distance Vector Routing
• Hierarchical Routing overview
  

• CSMA/CD
• Wireless 802.11
  

• Interconnection:  hubs and switches
• Layer 2 Addressing
• Given a router (or host) which needs to send to a specific IP address:  how does the sender know what the L2 addresss is? 
  
• Need a protocol to translate from Layer 3 to Layer 2:  Address Resolution Protocol
  

• Review: Last 3rd of the Course using UT's network as an example.
• MMedia, part 2:  Streaming Stored Audio and Video, focusing on terminology, Problems and Application Layer Solutions.