Section 2: Understanding the Host-to-Host Communications Model

In addition to session regulation, what else does the session layer offer?

- Efficient data transfer - CoS - Exception reporting of session layer, presentation layer, and application layer problems

What are the four layers of the TCP/IP model/stack?

- Link Layer - Internet Layer - Transport Layer - Application Layer

What are the characteristics of standards-based model?

- Multivendor software - Layered approach

What are the characteristics of older host-to-host models?

- Proprietary - Applications and combinatiosn of softawre controlled by one vendor

What are benefits of standardization?

- Reduces complexity in system design - Different vendors provide solutions for separate components - Facilitates modular engineering - Ensures interoperable technology - Accelerates component evolution - Makes teaching and learning about technology easier

What are the seven cateogries/layers of network functions outlined by the OSI reference model?

7 - Application 6 - Presentation 5 - Session 4 - Transport 3 - Network 2 - Data Link 1 - Physical

What can be used to look into PDUs from peer-to-peer communication for network troubleshooting, analysis, software and communications protocol development, and education?

A program for analyzing packets, such as Wireshark

What is a set of rules that are implemented in the software and hardware of each device?

A protocol

What is the significance of the TCP/IP model's Application layer's support for network APIs?

Allows programs that have been created for a particular operating system to access the network

Which OSI layer is closest to the user?

Application Layer (Layer 7)

What layer of the TCP/IP model is the equivalent of the session layer, presentation layer, and application layer of the OSI model?

Application layer

What layer of the TCP/IP model provides applications for file transfer, network troubleshooting, and internet activities, and also supports network APIs

Application layer

Which layer provides network services to the applications of the user, such as email, file transfer, and terminal emulation, by establishing the availabiltiy of intended communication partners and then synchronizing/establishing agreement on procedures for error recovery and control of data integrity?

Application layer

What is the general term for the PDU that is used at the application layer?

Data

What layer defines how data is formatted for transmission and how access to physical media is controlled?

Data Link Layer (Layer 2)

Which layer includes error detection and correction to ensure a reliable delivery of the data?

Data Link Layer (Layer 2)

What is information sent on a network referred to as?

Data or data packets

DARPA contracted Stanford University, BBN Technologies, and University College London to create a ___ ___ ___.

Data transmission protocol

The process of each layer removing the header that its peer layer added, after reaching the destination, and reading the information in the header to determine what to do with the data then handing the PDU up to the next layer for processing is known as ____.

De-encapsulation

How is peer-to-peer communication achieved?

Encapsulating data in a format that the peer layer will understand

The process of each layer adding its own header, and a trailer if applicable, before sending to to the following layer is known as _____.

Encapsulation

Information that is transmitted over a network must undergo a process of conversion at the sending and receiving ends of the communication. What is this conversion process known as?

Encapsulation and de-encapsulation of data

What is a usual Layer 2 trailer?

FCS

What are the extra characters added to the frame for error control purposes, and used by the receiver to detect whether the data is in error, known as?

FCS, Frame check sequence

What is a link layer PDU?

Frame

What are end devices called in the context of a network?

Hosts

What protocol operates at Layer 3 and is responsible for the transmission of data; it doe snot do any error correction itself

IP

Although this course refers to the TCP/IP stack, it has become common in the industry to shorten this term to "___ ____"

IP stack

What layer of the TCP/IP model is the equivalent of the network layer of the OSI model?

Internet layer

What layer of the TCP/IP model is where IP operates, and is responsible for routing data from the source to the destination by defining the packet and the addressing scheme, moving data between the link and transport layers, routing packets of data to remote hosts, and performing fragmentation and reassembly of data packets?

Internet layer

How does the application layer differ from other layers?

It does not provide services to any other OSI layer

What layer of the TCP/IP model involves components such as cables, connectors, and network cards and is concerned with hardware addresses?

Link layer

What layer of the TCP/IP model is the equivalent of both the physical and data link layers of the OSI model?

Link layer or Data link layer

Each Host-to-Host communication starts with a ______.

Message

Which layer provides connectivity and path selection between two host systems that may be located on geographically separate neworks, and manages the connectivity of these users by providing logical addressing?

Network Layer (Layer 3)

What are examples of standards-based models?

OSI and TCP/IP

What model provides a means of describing how data is transmitted over a netowrk, and addresses hardware software, and data transmission?

OSI reference model

What are the two different types of host-to-host models?

Older model Standards-based model

What means that the use of the technology is available and is free to the public?

Open

What are the packets of information called that are exchanged by protocols between each peer layer?

PDU

What is an Internet layer PDU?

Packet

What term means the equal of a person or object?

Peer

What means communication between equals?

Peer-to-peer communication

What layer defines certain specifications, such as timing of voltage changes, voltage levels, phyiscla data rates, maximum transmission distances, etc, that are needed for activating, maintainging, and deactivating the physical links between end devices?

Phyiscal Layer (Layer 1)

Which layer ensures that the information that is sent to the application layer of one system is readable by the application layer of another system, and has to translate among multiple data formats using a common format?

Presentation Layer (Layer 6)

What means that one company or a small group of companies control all use of the technology?

Prioprietary

Successful communication between hosts on a network requires many different _____.

Protocols

Why does hte transport layer break down large files into smaller segments that are less likely to incur transmission problems?

Reliable delivery of the files is important

What is a transport layer PDU?

Segment

Which layer establishes, manages, and terminates sessions between two communicating hosts, and also synchronizes dialog between the presentation layers of the two hosts and manages their data exchange?

Session Layer (Layer 5)

What protocol operates at Layer 4 and provides reliable or unreliable delivery of data and performs error correction before transmit?

TCP

Which layer 4 protocol is used when data loss cannot be tolerated (like in file transfer)?

TCP

What protocols operate at the Transport Layer (Layer 4)?

TCP and UDP

What is a set of protocols that define how devices should be connected over the Internet and how data should travel between them?

TCP/IP

What model provides a common reference for maintaining consistency within all types of network protocols and services, predates the OSI model, and whose primary purpose is to help you understand the functions and processes that are involved in data communication?

TCP/IP model

What organization is the world's largest developer of voluntary international standards, standards that help businesses to increase productivity while minimizing errors and waste?

The International Organization for Standardization, ISO

What else is the Link layer known as?

The network access layer

What two protocols make up TCP/IP?

Transmission Control Protocol Internet Protocol

What does TCP/IP stand for?

Transmission Control Protocol/Internet Protocol

Which layer defines services to segment, transfer, and reassemble the data for individual communications between end devices?

Transport Layer (Layer 4)

What layer of the TCP/IP model is the core of the TCP/IP architecutre, the layer where TCP and UDP operate, and is responsible for providing communication services directly to the application processes that are running on network hosts?

Transport layer

What layer of the TCP/IP model is the equivalent of the transport layer of the OSI model?

Transport layer

True/False - The TCP/IP reference model is not intended to be an implementation specification or to provide sufficient detail to precisely define the services of the network architecture.

True, the TCP/IP is not intended for those things

Which layer 4 protocol is used when some data loss is acceptable (when speed is more important that accuracy; for example, in video streaming)?

UDP

In the computer industry, priorietary is the opposite of ____.

open