Chapter 3 CCNA Study Guide

All communication methods have three elements in common, these are?

A. Message source- can be people, or electronic devices, that need to send a message to other individuals or devices.

B. Destination- receiver of the message and interpreter

C. Channel- consists of the media that provides the pathway over which the message travels from source to destination.

List requirements for common computer protocols.

A. Message Encoding

B. Message Formatting and Encapsulation

C. Message Size

D. Message Timing

E. Message Delivery Options

The first step to sending a message is encoding it. What is encoding?

Is the process of converting information into another acceptable form, for transmission.

How is decoding different from encoding?

Decoding reverses this process in order to interpret the information and Encoding is the process of converting information into another acceptable for, for transmission.

What is encapsulation?

The process of placing one message format (the letter) inside another message format (the envelope)

*De-encapsulation occurs when the process is reversed by the recipient and the letter is removed from the envelope

Explain how long messages or large frames are handled in a network to ensure delivery?

The long message will be sent in separate frames, with each frame containing a piece of the original message. Each frame will also have its own addressing information. At the receiving host, the individual pieces of the message are reconstructed into the original message.

Explain the following terms.

A. Message Timing

B. Access Method

C. Flow Control

D. Response Timeout

A. A series of steps that are necessary to convey a message so the recipient can properly decode and respond

B. Determines when someone is able to send a message. The knowing of when to being sending messages and how to respond when collisions occur

C. The timing and speed in which the message is sent in order for the recipient to understand

D. Rules that specify how long to wait for responses an what action to take if a response timeout occurs where the message is not received

Explain the following terms.

A. Unicast

B. Multicast

C. Broadcast

A. One-on-one delivery

B. One-to-many delivery

C. One-to-all delivery

Explain what protocol suite is and what devices implement or use them?

A group of inter-related protocols necessary to perform a communication function is called a protocol suite. It is implemented by hosts and networking devices in software, hardware or both

What is a protocol stack?

Shows how the individual protocols within a suite are implemented. Physical Layer, Rules Layer, and Content Layer

What do the lower layers in the protocol stack focus on?

A. Physical Layer- Two people, each with a voice that can say words out loud

B. Rules Layer- An agreement to speak in a common language

What do the upper layers in the protocol stack focus on?

Content Layer- There are actual words that are being spoken

What do networking protocols define?

A common format and set of rules for exchanging messages between devices

List some common networking protocols.

A. Hypertext Transfer Protocol (HTTP)

B. Transmission Control Protocol (TCP)

C. Internet Protocol (IP)

Describe some of the processes of networking protocols are responsible for.

A. How the message is formatted or structured

B. How networking devices share information about pathways with other networks

C. How and when error and system messages are passed between devices

D. The setup and termination of data transfer sessions

Explain in detail how the following protocols operate

A. HTTP- is an application protocol that governs the way a web server and a web client interact. HTTP defines the content and formatting of the requests and responses that are exchanged between the client and server. Both the client and the web server software implement HTTP as part of the application. HTTP relies on other protocols to govern how the messages are transported between the client and server.

B. TCP- is the transport protocol that manages the individual conversations. TCP divides the HTTP messages into smaller pieces, called segments. These segments are sent between the web server and client processes running at the destination host. TCP is also responsible for controlling the size and rate at which messages are exchanged between the server and the client.

C. IP- is responsible for taking the formatted segments from TCP, encapsulating them into packets, assigning them the appropriate addresses, and delivering them to the destination host.

D. Ethernet- is a network access protocol that describes two primary functions: communication over a data link and the physical transmission of data on the network media. Network access protocols are responsible for taking the packets from IP and formatting them to be transmitted over the media.

The protocols IP, HTTP, DHCP are all part of the protocol suite know as:

TCP/IP Protocol Suite

The TCP/IP protocol suite is and open standard. Explain what this means.

meaning these protocols are freely available to the public, and any vendor is able to implement these protocols on their hardware or in their software

Explain what a standards-based protocol is.

is a process that has been endorsed by the networking industry and approved by a standards organization

Explain why it's important to have standard based protocols.

the equipment or software may not be able to successfully communicate with products made by other manufacturers.

Explain what proprietary protocols are.

means one company or vendor controls the definition of the protocol or how it functions

Explain the protocol steps involved in during the communication process after a remote computer requests a webpage from a web server.

A. The web server prepares the HTML page as data to be sent

B. The application protocol HTTP header is added to the front of the HTML data. The header contains various information, including the HTTP version the server is using and a status code indicating it had information for the web client.

C. The HTTP application layer protocol delivers the HTML-formatted web page data to the transport layer. The TCP transport layer protocol is used to manage individual conversations

D. The IP information is added to the front of the TCP information. IP assigns the appropriate source and destination IP addresses. This information is known as an IP packet

E. The Ethernet protocol adds information to both ends of the IP packet, known as a data link frame. This frame is delivered to the nearest router along the path towards the web client. This router removes the Ethernet information, analyzes the IP packet, determines the best path for the packet, inserts the packet into a new frame, and sends it to the next neighboring router towards the destination. Each router removes and adds new data link information before forwarding the packet.

F. This data is now transported through the internetwork, which consists of media and intermediary devices.

G. Each protocol header is processed and then removed in the opposite order it was added. The Ethernet information is processed and removed, followed by the IP protocol information, the TCP information, and finally the HTTP information.

H. The web page information is then passed on to the client's web browser software.

Standards organizations are usually ____________, _______________ established to develop and promote the concept of open standards

Vendor-neutral

Non-profit organizations

Explain the function and responsibility of each of the following standards organizations.

A. The Internet Society (ISOC)

B. The Internet Architecture Boards(IAB)

C. The Internet Engineering Task Force(IETF)

D. The Institute of Electrical and Electronics Engineers (IEEE)

E. The International Organization for Standardization(ISO)

F. The Electronic Industries Alliance (EIA)

G. The Telecommunications Industry Association (TIA)

H. The International Telecommunications Union-Telecommunication Standardization Sector(ITU_T)

I. The Internet Corporation for Assigned Names and Numbers (ICANN)

A. Responsible for promoting the open development and evolution of Internet use throughout the world.

B. Responsible for the overall management and development of Internet standards.

C. Develops, updates, and maintains Internet and TCP/IP technologies. This includes the process and documents for developing new protocols and updating existing protocols know as Request for Comments (RFC) documents.

D. Organization of electrical engineering and electronics dedicated to advancing technological innovation and creating standards in a wide area of industries including power and energy, healthcare, telecommunications, and networking

E. Ensure that products and services are safe, reliable and of good quality. For business, they are strategic tools that reduce costs by minimizing waste and errors and increasing productivity.

F. Best known for its standards related to electrical wiring, connectors, and the 19-inch racks used to mount networking equipment.

G. Responsible for developing communication standards in a variety of areas including radio equipment, cellular towers, Voice over IP (VoIP) devices, satellite communications, and more. Figure 2 shows an example of an Ethernet cable meeting TIA/EIA standards.

H. defines standards for video compression, Internet Protocol Television (IPTV), and broadband communications, such as a digital subscriber line (DSL).

I. Based in the United States, coordinates IP address allocation, the management of domain names, and assignment of other information used TCP/IP protocols.

List the names of the following common Standards of IEEE 802 Working groups:

A. 802.3

B. 802.11

C. 802.15

D. 802.16

A. Ethernet Working Group

B. Wireless LAN Working Group

C. Wireless PAN Working group

D. Broadband Wireless Access Working Group

Explain the benefits of using a layered model to describe network protocols and operations

A. Assisting in protocol design because protocols that operate at a specific layer have defined information that they act upon and a defined interface to the layers above and below.

B. Fostering competition because products from different vendors can work together

C. Preventing technology or capability changes in one layer from affecting other layers above and below

D. Providing a common language to describe networking functions and capabilities.

There are two basic types of networking models. Explain both.

A. Protocol Model- It describes the functions that occur at each layer of protocols within the TCP/IP suite

B. Reference Model- Provides consistency within all types of network protocols and services by describing what has to be done at a particular layer, but not prescribing how it should be accomplished. The OSI model is a widely known internetwork reference model

Explain what happens at each of the OSI model layers.

A. Application- Contains protocols used for the process-for-process communication

B. Presentation- Provides for common representation of the data transferred between application layer services

C. Session- Provides services to the presentation layer to organize its dialogue and to manage data exchange

D. Transport- Defines services to segment, transfer, and reassemble the data for individual communication between the end devices

E. Network- Provides services to exchange the individual pieces of data over the network between identified end devices

F. Data Link- Describes method for exchanging data frames between devices over a common media

G. Physical- Describes the mechanical, electrical, functional, and procedural means to activate, maintain , and de-activate physical connections for bit transmission to and from a network device

Explain what happens at each of the TCP/IP model layers.

A. Application- Represents data to the user, plus encoding and dialog control

B. Transport- Supports communication between various devices across diverse networks

C. Internet- Determines the best path through the network

D. Network Access- Controls the hardware devices and media that make up the network

What is segmentation?

Breaking communications into pieces

What are two primary benefits to segmenting data over a network?

A. By sending smaller individual pieces from source to destination, many different conversations can be interleaved on the network, called multiplexing

B. Segmentation can increase the efficiency of network communications. If part of the message fails to make it to the destination, due to failure in the network or network congestion, only the missing parts need to be retransmitted.

The process used to interleave the pieces of separate conversations together on the network is called?

Multiplexing

What is the downside to using segmentation and muliplexing to transmit messages across a network?

The level of complexity that it adds to the process

As application data is passed down the protocol stack on its way to be transmitted across the network media, various protocols add information to it at each level. This is commonly known as

Protocol Data Unit

OSI model describes the processes of encoding, formatting, segmenting, and encapsulating data for transmission over the network. What happens at the network layer and data link layer.

A. Network Layer- Delivers the IP packet from the original source to the final destination, either on the same network or to a remote network

B. Data Link Layer- Delivers the data link frame from one network interface card to another NIC on the same network

A Layer 3 or Network layer address (IP) has two parts, list and explain both.

A. Source IP Address- The IP address of the sending device, the original source of the packet.

B. Destination IP Address-The IP address of the receiving device, the final destination of the packet

An IP packet contains two IP addresses, list and explain both.

A. Source data link address- The physical address of the device's NIC that is sending the data link frame.

B. Destination data link address- The physical address of the NIC that is receiving the data link frame. This address is either the next hop router or of the final destination device

What is the purpose of a data link address?

Indicates the original source and final destination

Which two addresses are required to send data to another host on the same network?

A. Network Portion

B. Host Portion

Explain how a host send a message to a remote network?

When the sender of the packet is on a different network from the receiver, the source and destination IP addresses will represent hosts on different networks. This will be indicated by the network portion of the IP address of the destination host.

If no default gateway address is configured in the host TCP/IP settings, or if the wrong default gateway, is specified, what happens to messages addressed to hosts on remote access?