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CCNA Chapter 2
CCNA Cisco Network Fundamentals Version 4.0 Chapter 2
Question | Answer |
---|---|
What are the three basic elements of communication? | Sender, Receiver, Channel |
Network | Multiple computers connected together using a communication system capable of carrying data, voice, video, etc. |
Segmentation | Division of a data stream into smaller pieces |
Multiplexing | Interleaving segmented pieces of separate communications together over a network. |
Continuous data stream's disadvantages | A massive stream of bits: no other device can use network; failure means whole msg would be lost. |
Devices | One of three components of a network (devices, media, services), the machines that make up a network. |
Media | One of three components of a network (devices, media, services), the wires or wireless connections between devices. |
Services | One of three components of a network (devices, media, services), the software that run on a device. Network services provide a response to a request. Processes provide the functionality that directs and moves the messages through the network. |
The three components of a network | Devices, media, services. (Hardware, cables, software.) |
Host | End device. Anything used by an End User. |
Intermediary device | A device that connects directly to end user devices or provides end user routing to other networks. |
Intermediary devices (examples) | Network Access Devices (hubs, switches, wireless access points). Internetworking devices (routers). Communication servers and modems. Security devices (firewalls). |
End user devices (examples) | (Computers, servers, printers, VoIP phones, security cameras, mobile devices.) |
Intermediary devices functions | Determine path using host address and current path info. Regenerate and retransmit data. Maintain info about existing paths. Notify devices of errors and link fail. Direct along alt. paths when failures. QoS priorities. Permit or deny based on security. |
Media types | Metallic wires. Fiber optic. Wireless. |
LAN | Local Area Network. A network in a single geographical area. More modern definition: A network (can be spread out) under a single admiration organization that governs the security and access control polices. |
WAN | Wide Area Network. LANs interconnected by a Telecommunication Service Provider. |
Internet | A global mesh of internetworks of connected ISPs. |
Intranet | Private collection of LANs and WANs belonging to an organization. |
TCP/IP Model Layers | Application, Transport, Internet, Network Access |
PDU | Protocol Data Unit. The form a piece of data takes at any layer. |
Segment | Transport layer PDU |
Packet | Internetwork layer PDU |
Frame | Network access layer PDU |
TCP | Transmission Control Protocol. A transport layer protocol. Divides the msg into smaller pieces (segments). Controls the size and rate of messages. |
IP | Internet Protocol. Internetwork layer protocol. Takes formatted segments of messages, adds addresses to encapsulate into packets, and selects best path to destination. |
Application (TCP/IP) | Represents data to the user plus encoding and dialog control. |
Transport (TCP/IP) | Supports communication between diverse devices across diverse networks. |
Internet (TCP/IP) | Determines the best path through the network. |
Network Access (TCP/IP) | Controls the hardware devices and media that make up the network. |
OSI Model Layers | 7. Application 6. Presentation 5. Session 4. Transport 3. Network 2. Data Link 1. Physical |
Application (OSI) | Layer 7. Provides the means for end-to-end connectivity between individuals in the human network using data network. |
Presentation (OSI) | Layer 6. Provides for common representation of the data between the Application layer services. |
Session (OSI) | Layer 5. Provides services to the Presentation layer to organize its dialog and to manage data exchange. |
Transport (OSI) | Layer 4. Defines services to segment, transfer, and reassemble the data for individual communication between the end devices. |
Network (OSI) | Layer 3. Provides services to exchange the individual pieces of data over the network between identified end devices. |
Data Link (OSI) | Layer 2. Describes methods for exchanging data frames between devices in a common media. |
Pysical (OSI) | Layer 1. Describes the mechanical, electrical, functional, and procedural means to activate, maintain, and de-activate physical connections for bit transmissions. |
What address and PDU is used at OSI layer 3? | IP Address and Packet |
What address and PDU is used at OSI layer 2? | MAC Address and Frame |