Transmission Control Protocol (TCP) and Packet-Switching Hardware

1
Transmission Control Protocol (TCP) and
Packet-Switching Hardware

• Devang Parekh
• EE290F
• 4/15/04

2
Outline

• TCP
• OSI 7 Layer
• SYN/ACK
• Different Flavors
• Routers
• What they do
• Protocols

3
OSI 7 Layer Model
4
OSI 7 Layer Model

• Physical (Layer 1)
• Physical link layer
• Electrical impulse, radio, optical
• Lowest layer of the OSI Model

5
OSI 7 Layer Model

• Data Link (Layer 2)
• Data packets encoded into bits
• Media Access Control (MAC) Layer
• Controls how a computer gains access to a link
  and transmission on that link.
• Logical Link Control (LLC) Layer
• Frame synchronization, flow control, error
  checking

6
OSI 7 Layer Model

• Network (Layer 3)
• Switching and routing performed at this layer
• Addressing, internetworking, error handling,
  congestion control, packet sequencing
• IP

7
OSI 7 Layer Model

• Transport (Layer 4)
• Transparent transfer of data
• End-to-end recovery
• Flow control
• TCP/UDP

8
OSI 7 Layer Model

• Session (Layer 5)
• Manages end-to-end connections
• Presentation (Layer 6)
• Acts as middleware for application layer
• Application (Layer 7)
• The program you use

9
TCP/UDP

• UDP (User Datagram Protocol)
• Provides multiplexing/demultiplexing to IP
• No congestion control
• Advantage does not increase delay over
  connection
• Audio/video stream

10
TCP/UDP

• TCP (Transmission Control Protocol)
• Reliable, in-order delivery
• Multiplexing/Demultiplexing to IP
• Congestion control and avoidance
• Increases delay
• File transfer, chat

11
3-way handshake
12
3-way handshake

• Goal Agree on sequence numbers

13
State Diagram
14
Header
15
Header

• Ports self-explanatory
• Sequence number, acknowledgement used in
  sliding window protocol
• Flags
• SYN/FIN establishing/terminating connections
• ACK acknowledgement is valid
• URG urgent data
• RESET- abort connection

16
Sliding Window Protocol

• Stop Wait
• Transmit
• Wait for Ack
• If timeout send again
• Go-back-n
• Transmit n packets
• If timeout at packet k, send again from k, k1,

17
Congestion Control

• Telephone Network
• Reservation
• TCP
• Adapt rate to congestion
• Algorithm should be fair
• UDP
• Hope for the best

18
Congestion Control

• Ex. TCP-Reno
• Congested -gt decrease rate
• Uncongested -gt increase rate
• Additive-Increase Multiplicative-Decrease (AIMD)

19
Congestion Control

• Fast retransmit
• Fast Recovery
• Slow Start
• Flow Control

20
Congestion Control

• Fast Retransmit
• ACK next expected ACK

21
Congestion Control

• Slow Start
• Discover available bandwidth fast

22
Congestion Control

• Flow Control
• Receiver advertises window

23
Routers

• IP Addressing
• Classes

24
Routers

• Functions
• Topology update
• Shortest path
• Switching

25
Routers

• Topology Update
• Link State
• Communicates name and distance to each neighbor
• Distance Vector
• Communicates current distance estimates to every
  other node
• Path Vector
• Communicates current preferred path to every
  other node

26
Routers
27
Routers
28
Routers

• The Cisco 1760 Modular Access Router offers small
  and medium-sized businesses and enterprise small
  branch offices a 19-inch rack-mount access
  solution designed to enable them to grow their
  e-business capabilities. The two different
  versions of the Cisco 1760 Modular Access Router,
  the base version Cisco 1760 router and the
  preconfigured multiservice-ready Cisco 1760-V
  router, address the needs of customers who want
  to deploy e-business applicationsnow or in the
  future.
• The Cisco 1760 router, as a modular platform in
  a 19-inch rack-mount form factor, offers
  customers secure Internet and intranet access, as
  well as the capability to implement a variety of
  e-business and voice applications. This includes
  voice over IP (VoIP), virtual private network
  (VPN) access, and business-class digital
  subscriber line (DSL) as required (refer to
  Figure 1).
• The Cisco 1760 router is part of a broad
  portfolio of access routers optimized to deliver
  intelligent services such as quality of service
  (QoS), manageability, availability, and security.
• The two different versions of the Cisco 1760
  Modular Access Router, the base version Cisco
  1760 router and the Cisco 1760-V router, address
  the needs of customers who want to deploy
  transformation technologies such as converged
  voice and data, IP telephony, or
  videoconferencing.