Wednesday, February 10, 2016

CCNAv1 Chapter 3 Notes - Network Protocols, TCP/IP, and Packet Frames

Chapter 3
CCNAv1
Message Delivery Options:
  • Unicast: one to one
  • Multicast: one to many
  • Broadcast: one to all

Networking Protocols
  • Protocols are rules that govern communication.
  • Procol Suites are a set of rules together to solve a problem.

Networking protocols control how...
  • How the message is formatted.
  • The process by which networking devices share information about pathways with other networks. (Network cabling)
  • How and when error and system messages are passed between devices.
  • The setup and termination of data transfer sessions.

Interaction of Protocols
  • Application Protocol - Hypertext Transfer Protocol (HTTP)
  • Transport Protocol - Transmission Control Protocol (TCP)
  • Internet Protocol - Internet Protocol (IP)
  • Network Access Protocols - Data link / physical layers.


Open Standards
Open Standards means anyone can submit changes to it. Organizations are:
  • The Internet Society (ISOC)
  • The Internet Architecture Board (IAB)
  • Internet Engineering Task Force (IETF)
  • Electrical & Electronic Engineers (IEEE)

IEEE Groups
  • IEEE 802.3 - Ethernet
  • IEEE 802.11 - WiFi

OSI MODEL
7. Application
6. Presentation
5. Session
4. Transport
3. Network
2. Data Link
1. Physical

“All People Seem To Need Domino’s Pizza”

TCP/IP LAYERS -- Don’t confuse w/

OSI MODEL DESCRIPTION
1] Physical: Provides mechanical, electrical, procedural and functional standards to activate, maintain & deactivate connections to and from network devices.
Transmits data to bits.

2] Data Link: Provides methods for exchanging data frames over common network media.
MAC addresses are used at this layer.

3] Network: Provides services to exchange the pieces of data over the network between end devices.
IP Addresses are used at this layer. Routers being the most involved in this layer.
(Table 3-3)

4] Transport: Defines services to segment, transfer, & reassemble the data for individual communications between end devices.

5] Session: Provides services and the presentation layer to organize the dialogue and manage data exchange.

6] Presentation: Provides common representation of data transferred between application layer services.

7] Application: Provides the means for end to end connectivity between individuals using the data network.

Communicating Messages - Data Encapsulation
  • Segmenting Message Benefits
    • Different conversations can be interleaved
    • Increased reliability of network communication
  • Segmenting message disadvantage
    • Increased level of complexity

Protocol Data Units (PDU)
  • Data
  • Segment
  • Packet
  • Frame
  • Bits
At x layer, data is y:
Bits = Physical
Frame = Network Access
Packet = Internet
Segment = Transport
Application = Data
Network Addresses and Data Link Addresses
Physical
Data Link
Network
Transport
Upper Layers
Timing and synchronization bits.
Destination and source physical addresses.
Destination and source logical network addresses.
Destination and source process number (ports).
Encoded application data.

Communicating with Devices Over the Same Network
DATA LINK
ETHERNET FRAME HEADER
DATA LINK
ETHERNET FRAME HEADER
NETWORK LAYER IP PACKET HEADER
NETWORK LAYER IP PACKET HEADER
NETWORK LAYER IP PACKET HEADER
Destination
Source
Source
Destination
DATA

CC-CC-CC-CC-CC-CC

AA-AA-AA-AA-AA-AA
Network
192.168.1.-

Host 110
Network
192.168.1.-

Host 9

DATA


ARP: Address Resolution Protocol
  • Gets the MAC address from the IP address.
  • For systems on the same network.

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