Network Protocol Architectures Flashcards

Flashcards based on lecture notes on Network Protocol Architectures.

What is a network protocol?

A set of rules that enable successful communication, dictating the syntax, semantics, and timing of communication between devices.

What three aspects of communication does a protocol define?

What is to be communicated, how it is to be communicated, and when it is to be communicated.

What are the three elements of a computer communication protocol?

Syntax, Semantics, and Timing.

Why are standards necessary in networking?

To ensure interconnectivity and interoperability between various networking hardware and software components, preventing isolated islands of users.

What are de facto standards?

Standards that are traditionally used and adopted for widespread use but are not approved by any organized body.

What are de jure standards?

Standards that are legislated and approved by an officially recognized body.

Name three types of organizations that create standards.

Standards creation committees, forums, and government regulatory agencies.

Differentiate between Protocols, Reference Model, and Reference Architecture.

Protocols are a set of rules governing communication. A Reference Model describes data movement and naming schemes. A Reference Architecture is an arrangement of protocol layers with associated tasks.

What are the two fundamental network models?

The International Standards Organization/Open Systems Interconnection (ISO/OSI) reference model and the Transport Control Protocol/Internet Protocol (TCP/IP) protocol suite.

What is the OSI Reference Model?

A seven-layer model of data communications that describes how information moves from a software application on one computer through a network medium to a software application on another computer.

How is actual communication made possible using the OSI model?

By using communication protocols, a formal set of rules and conventions that govern how computers exchange information over a network medium and implement the functions of one or more OSI layers.

Name four protocol groups.

LAN Protocols, WAN Protocols, Routing Protocols, and Network Protocols.

List the seven layers of the OSI reference model.

Application, Presentation, Session, Transport, Network, Data Link, and Physical.

What is the main function of the Application Layer in the OSI model?

Identifying communication partners, determining resource availability, and synchronizing communication.

What is the main function of the Presentation Layer in the OSI model?

Providing coding and conversion functions to ensure information sent from one system's application layer is readable by another system's application layer.

What is the main function of the Session Layer in the OSI model?

Establishing, managing, and terminating communication sessions between presentation layer entities.

What is the main function of the Transport Layer in the OSI model?

Implementing reliable inter-network data transport services, including flow control, multiplexing, virtual circuit management, and error checking and recovery.

What is the main function of the Network Layer in the OSI model?

Providing routing and related functions to enable multiple data links to be combined into an inter-network, including logical addressing.

What is the main function of the Data Link Layer in the OSI model?

Providing reliable transit of data across a physical network link, including physical addressing, network topology, error notification, sequencing of frames, and flow control.

What is the main function of the Physical Layer in the OSI model?

Placing information on the medium, defining electrical, mechanical, procedural, and functional specifications for activating, maintaining, and deactivating the physical link between communicating network systems.

What is the purpose of the Application Layer in the ISO seven-layer reference model?

To allow access to network resources.

What is the purpose of the Presentation Layer in the ISO seven-layer reference model?

To translate, encrypt, and compress data.

What is the purpose of the Session Layer in the ISO seven-layer reference model?

To establish, manage, and terminate sessions.

What is the purpose of the Transport Layer in the ISO seven-layer reference model?

To provide reliable process-to-process message delivery and error recovery.

What is the purpose of the Network Layer in the ISO seven-layer reference model?

To move packets from source to destination and to provide internetworking.

What is the purpose of the Data Link Layer in the ISO seven-layer reference model?

To organize bits into frames and to provide hop-to-hop delivery.

What is the purpose of the Physical Layer in the ISO seven-layer reference model?

To transmit bits over a medium; to provide mechanical and electrical specifications.

What is the key function of the Data Link Layer?

Direct link control and access to media, providing reliable transfer of data across media with physical addressing, network topology, error notification, and flow control.

Which OSI layer is concerned with transportation issues between hosts and data transport reliability, and establishes, maintains, and terminates virtual circuits?

The Transport Layer.

Which OSI layer ensures data is readable by the receiving system and negotiates data transfer syntax for the application layer?

Presentation Layer.

Which OSI layer provides network services to application processes such as electronic mail, file transfer, and terminal emulation?

Application Layer.

What was the ARPANET protocol suite?

A common protocol funded by DARPA that introduced the fundamental concept of layering, from which the TCP/IP suite evolved.

What is the primary purpose of TCP/IP?

Information sharing and research collaboration among government agencies and research institutes.

What are the five layers in the TCP/IP architecture?

Application, Transport, Network (Internet), Data Link, and Physical.

What is the purpose of the Transport layer in network models?

End-to-End Management - Links application layer to network, Segmenting and Tracking, and Flow control.

What is the purpose of the Network layer in network models?

Deciding where the message goes: Addressing and Routing.

What is the purpose of the Data Link layer in network models?

Move a message from one device to the next: Controls hardware, Formats the message, and Error Checking.

What is the purpose of the Physical layer in network models?

Transmits the message.

In the context of network architectures, what is the difference between a logical and a physical connection?

A logical connection exists only in the software, while a physical connection exists in the hardware.

In a network architecture, which layer contains a physical connection?

Only the lowest layer contains a physical connection; all higher layers contain logical connections.

Define Encapsulation.

The adding of information over pre-existing information at each layer of the TCP/IP model as data is passed from user to web browser and back.