CCNA v 1.1 Review: OSI Model Layers

In late 2010, Cisco did a “minor revision” of the CCNA curriculum, which includes discussion of some newer technologies. The two courses that comprise the CCNA exam prep are ICND1 and ICND2. This series of posts can help students understand what types of information are required to pass the latest version of the CCNA exam. Please Note: This is only intended as a review. Additional training and knowledge are needed in order to take and pass the CCNA exam. These posts do not help with the simulation portion of the test.

OSI Layer Purpose Examples
Application Provides services to network applications and responsible for determining resource availability, identifying communication peers, and synchronizing communication between the applications.
  • Simple Mail Transport Protocol (SMTP)
  • Telnet
  • File Transfer Protocol (FTP)
  • Trivial File Transfer Protocol (TFTP)
  • HyperText Transfer Protocol (HTTP)
Presentation Provides the coding and conversion functions that are applied to the data to/from the application layer and ensures that there is a common scheme used to bundle the data between the two ends.
  • ASCII (text)
  • EBCDIC (text)
  • JPEG (image)
  • GIF (image)
  • TIFF (image)
  • MPEG (sound/video)
  • Quicktime (sound/video)
Session Establishing, maintaining, and terminating communications sessions between upper layer applications.
  • Session Control Protocol (SCP)
  • Remote Procedure Call (RPC) from Unix
  • Zone Information Protocol (ZIP) from AppleTalk
Transport Responsible for end-to-end data transmission. Can be either reliable (connection-oriented) or best effor (connectionless). Organizes data from various upper layer applications into data streams, handles end-to-end flow control, multiplexing, virtual circuit management, and error checking and recovery.
  • Transmission Control Protocol (TCP) from IP
  • User Datagram Protocol (UDP) from IP
Network Allows both connection-oriented and connectionless data flows to access the network. The network layer addresses help define a network hierarchy. Network devices are normally grouped together based on their common network layer address.
  • Internet Protocol (IP)
Data Link Provides either reliable or best effort transmission of data across a physical medium. Most networks use a best effort data link, such as Ethernet. The data link Layer for LAN’s provides a physical address to each device called a Media Access Control (MAC) address. MAC addresses are typically burned into the network interface card (NIC). The LAN data link layer also uses a Logical Link Control (LLC) to indicate the type of network layer data that is encapsulated inside the frame. LAN

  • Enternet/IEE 802.3 (include Fast Ethernet, Gigabit Ethernet, etc.)
  • Token Ring/IEEE 802.5
  • FDDI (from ANSI)

WAN

  • High-Level Data-Link Control (HDLC)
  • Point-to-Point Protocol (PPP)
  • Frame Relay
Physical Defines the electrical, mechanical, and functional specifications for maintaining a physical link between network devices. This layer is responsible for such characteristics as voltage levels, timing and clock rates, maximum transmission distances, and the physical connectors used. LAN

  • Category 5 cabling

WAN

  • EIA/TIA-232
  • EIA/TIA-449
  • V.35

In the next post we’ll go over OSI-Model vs. TCP/IP Protocol Suite and the TCP/IP transport layer protocols.

Excerpted and available for download from Global Knowledge White Paper: CCNA v1.1 Exam Review: Critical Concepts of the 640-802 CCNA Exam

Resources:
CCNA Cert Check
CCNA Exam Prep Mobile App

Related Courses:
ICND1 — Interconnecting Cisco Network Devices 1
ICND2 — Interconnecting Cisco Network Devices 2
CCNAX — CCNA Boot Camp v1.1

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1 comment

  1. Ras menelik Reply

    Thank you for your great information.i want certification for CCNA this year,i hope ill get more helpfull information on this site.