OSI Layers Flashcards
OSI
Open Systems Interconnection
What are the OSI Layers?
Physical
Datalink
Network
Transport
Session
Presentation
Application
is the lowest layer in the OSI model
Physical Layer
serves as the interface between the data transmission equipment and the physical transmission medium
Physical Layer
Converting the data into a stream of bits and modulating them onto a carrier signal.
Signal Encoding
Includes factors such as distance, bandwidth, noise immunity, and cost.
Transmission Media
Converting the digital signal into an analog signal and amplifying it.
Signal Transmission
Receiving the modulated signal from the physical medium and converting it back into a digital signal for transmission
Signal Reception
Physical Layer Protocols
Ethernet, Wi-Fi, Bluetooth
Second layer of the OSI model
Data-Link Layer (DLL)
transports data between network nodes in WAN or LAN
Protocol Layer
The primary function of this layer is to ensure error-free data transfer from one node to another across the physical layer.
Data-Link Layer
Data-Link Layer is divided into two sublayers:
Logic Link Control (LLC)
Media Access Control (MAC)
are used by DLL to define how data is transmitted over the physical layer, such as the type of media access method, data framing format, and error detection and correction techniques
Protocols
Common DLL protocols
SDLC, HDLC, SLIP, PPP, LCP, LAP, NCP, Ethernet, Token Ring, ATM
is a collection of a data field in which a network layer datagram is put along with a number of data fields.
Frame
The packet received from the Network layer is divided into frames depending on the frame size of ____
Network Interface Card (NIC)
The data-link layer ensures _______, allowing two machines to transmit data simultaneously.
Flow Control
Error Detection Techniques
Parity Check, Checksum, CRC
Types of Errors
Single Bit, Multiple Bit, Burst
the receiving node not only detects errors but also determines where the faults occurred in the frame
Error Detection
involves determining the exact number of corrupted bits and the location of the corrupted bits.
Error Correction
maintains the communication link between two network devices
Logical Link Control (LLC)
regulates data transmission between two devices
Media Access Control (MAC)
Third layer of the OSI model
Network Layer
This is the place where most routing and network stuff resides and controls the logical boundaries of the network
Network Layer
The main aim of this layer is to deliver packets from source to destination across multiple links or networks.
Network Layer
The network layer divides segments from the transport layer into smaller units called _____ on the sender’s device and reassembles these packets on the receiving device.
packets
Its main job is to get packets from one network to another
Router
convey data packets from the source to the destination through a variety of hops or links. It also manages how the subnet works.
Network Layer
Network Layer Protocols
IPv4, IPv6, RIP, OSPF, EIGRP, BGP, ICMP, IPsec, IPX, NAT, GRE
Fourth layer of the OSI model
Transport Layer
manages network traffic between hosts and end systems to ensure complete data transfers.
Transport Layer
This layer coordinates data transfer between system and hosts, including error-checking and data recovery
Transport Layer
is a communications standard for delivering data and messages through networks
Transmission Control Protocol (TCP)
is a communications protocol that is primarily used to establish low-latency and loss-tolerating connections between applications on the internet
User Datagram Protocol (UDP)
A combination of an IP address, a port number, and the protocol being used
Socket
are the abstraction used by programmers.
Sockets
can be thought of as a communications cable running from one machine to another
Socket
Fifth layer of the OSI model
Session Layer
Its main aim is to establish, maintain and synchronize the interaction between communicating system.
Session Layer
defines how to start, control and end conversations between
applications
Session Layer
Session Layer Protocols
ADSP, RTP, PPTP, PAP, RPC, SDP
protocol used to set up a session for exchanging data between various networking devices. It also provides the functionality of flow-control at the Transport layer.
AppleTalk Data Stream Protocol (ADSP)
allows only that type of message, which carries data from the source to the destination
Real-time Transport Protocol (RTP)
networking standard for connecting to virtual private networks (VPN)
Point-to-Point Tunneling Protocol (PPTP)
password-based authentication protocol used by Point to Point Protocol (PPP) to validate users
Password Authentication Protocol (PAP)
is done at the time of the initial link establishment and verifies the identity of the client using a two-way handshake
PAP Authentication
is a protocol that is used when a
computer program causes a
procedure (or a sub-routine) to
execute in a different address space without the programmer explicitly coding the details for the remote interaction
Remote Procedure Call (RPC)
is a protocol that supports streams of sockets over Remote Direct Memory Access (RDMA) network fabrics
Sockets Direct Protocol (SDP)
The session layer sets up connections called _____ for devices to share data, allow remote access, and manage files.
Sessions
Sixth layer of the OSI model
Presentation Layer
This layer is also known as the Translation Layer
Presentation Layer
Presentation Layer is also known as ___________
Translation Layer
The main responsibility of this layer is to provide or define the data format and encryption.
Presentation Layer
The presentation layer is also called as ___________ since it is responsible for maintaining the proper syntax of the data which it either receives or transmits to other layer(s).
Syntax Layer
This layer takes care that the data is sent in such a way that the receiver will understand the information (data) and will be able to use the data efficiently and effectively.
Presentation Layer
to reduce the number of bits which is to be transmitted
Data Compression
ability of computers to exchange and make use of information
Interoperability
this layer takes care of any issues occurring when transmitted data must be viewed in a format different from the original format.
Presentation Layer
Most important layer of the OSI model
Presentation Layer
is the proprietary network protocol that offers services to macOS or the classic macOS.
Apple Filing Protocol (AFP)
is the protocol which is used to provide ISO presentation services on the top of TCP/IP based protocol stacks
Lightweight Presentation Protocol (LPP)
is the network protocol which is used to access file, print, directory, clock synchronization, messaging, remote command execution and other network service functions.
NetWare Core Protocol (NCP)
is basically the implementation of the presentation layer in the OSI model, which provides or defines various primitive data types, constructed data types and also several types of data representations.
Network Data Representation (NDR)
is the standard for the description and encoding of data. It is useful for transferring data between computer architectures and has been used to communicate data between very diverse machines.
External Data Representation (XDR)
Converting from local representation to XDR
Encoding
Converting XDR into local representation
Decoding
provides security to the data that is being transferred between the web browser and the server.
Secure Socket Layer (SSL)
Seventh layer of the OSI model
Application Layer
deals directly with applications
Application Layer
is responsible for displaying data and images to the user in a format humans can recognize
Application Layer
identifies the parties as they communicate, assesses service quality between them, and deals with issues such as constraints on data syntax, user authentication, and privacy.
Application Layer
Application Layer Protocols
HTTP, FTP, POP, SMTP, DNS
is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems.
Hypertext Transfer Protocol (HTTP)
is a standard communication protocol used for the transfer of computer files from a server to a client on a computer network.
File Transfer Protocol (FTP)
is a type of computer networking and Internet standard protocol that extracts and retrieves email from a remote mail server for access by the host machine.
Post Office Protocol (POP)
is a TCP/IP protocol used in sending and receiving email.
Simple Mail Transfer Protocol (SMTP)
is the phonebook of the Internet
Domain Name System (DNS)
terminates network traffic, performs TLS/SSL decryption as needed, inspects messages, makes routing decisions based on its content, initiates a new TCP connection to the appropriate upstream server, and writes the request to the server.
Layer 7 Load Balancer
can consider the actual content of each message to ensure the best experience for any user, device,
and location, while meeting requirements for compliance, content localization, and efficiency
Layer 7 Load Baalncing