OSI model

Layer 2

Data Link Layer

Connection less service: It is a one phase process and includes _____.

Data Transfer

Data Link Layer is divided into two sub layers :

Logical Link Control (LLC) Media Access Control (MAC)

The Receiver's MAC address is obtained by placing an ARP(Address Resolution Protocol) request onto the wire asking "Who has that IP address?" and the destination host will reply with its _______.

MAC address

OSI model

Open Systems Interconnection model

A ______is a specific block of information transferred over a network.

PDU

Protocol Data Unit

PDU

Layer 1

Physical Layer

Layer 6

Presentation Layer

Layer 5

Session Layer

Layer 4

Transport Layer

The packet received from Network layer is further divided into frames depending on the frame size of NIC(Network Interface Card). DLL also______Sender and Receiver's MAC address in the header.

encapsulates

Data encryption translates the data into another form or code. The encrypted data is known as the cipher text and the decrypted data is known as plain text. A key value is used for encrypting as well as decrypting data:

encryption/decryption

Data link layer provides the mechanism of ______in which it detects and retransmits damaged or lost frames.

error control

Main function of the data link layer is to make sure data transfer is _____from one node to another, over the physical layer.

error free

The data rate must be constant on both sides else the data may get corrupted thus , flow control coordinates that amount of data that can be sent before receiving acknowledgement.

flow control

Packet in Data Link layer is referred as:

frame

Data Link layer PDU

frame ( or series of bits)

______ is a function of the data link layer. It provides a way for a sender to transmit a set of bits that are meaningful to the receiver. This can be accomplished by attaching special bit patterns to the beginning and end of the frame.

framing

Framing, Physical addressing, Error control, Flow Control, and Access control

functions of the data Link layer

Routing and logical addressing

functions of the network layer

Bit synchronization, Bit rate control, Physical topologies, and Transmission mode

functions of the physical layer

Translation, Encryption/ Decryption, and Compression

functions of the presentation layer

Session establishment, maintenance and termination, Synchronization, and Dialog Controller

functions of the session layer

Segmentation and Reassembly and Service Point Addressing

functions of the transport layer

In order to identify each device on internetwork uniquely, network layer defines an addressing scheme. The sender & receiver's IP address are placed in the header by network layer. Such an address distinguishes each device uniquely and universally.

logical addressing

Network Layer, Data Link Layer and Physical Layer are also known as ______ or________.

lower layers hardware layers

Transport layer PDU

segment

At sender's side: Transport layer receives the formatted data from the upper layers, performs _____ and also implements _____ to ensure proper data transmission. It also adds _________ in its header and forwards the segmented data to the Network Layer.

segmentation flow & error control source and destination port number

This layer accepts the message from the (session) layer , breaks the message into smaller units . Each of the segment produced has a header associated with it. The transport layer at the destination station reassembles the message.

segmentation and reassembly

The data in the transport layer is referred to as

segments

In order to deliver the message to correct process, transport layer header includes a type of address called service point address or port address. Thus by specifying this address, transport layer makes sure that the message is delivered to the correct process

service point addressing

The layer allows the two processes to establish, use and terminate a connection:

session establishment, maintenance and termination

responsible for establishment of connection, maintenance of sessions, authentication and also ensures security

session layer

_____ are Data Link Layer devices

switch & bridge

______ allows a process to add checkpoints which are considered as synchronization points into the data. These synchronization point help to identify the error so that the data is re-synchronized properly, and ends of the messages are not cut prematurely and data loss is avoided.

synchronization

Examples of _____ are, ASCII to EBCDIC

translation

Physical layer also defines the way in which the data flows between the two connected devices. The various transmission modes possible are: Simplex, half-duplex and full-duplex.

transmission mode

provides services to application layer and takes services from network layer

transport layer

responsible for the End to End delivery of the complete message

transport layer

Layer 7

Application Layer

functions of the Application layer are:

FTAM-File transfer access and management

OSI developed by the

ISO

ISO stands for

International Organization of Standardization

Network layer is implemented by networking devices such as___

routers

functions of the Application layer are:

Mail Services

Data Link layer is handled by the ______and device drivers of host machines.

NIC (network interface card)

Layer 3

Network Layer

functions of the Application layer are:

Network Virtual Terminal

When a single communication channel is shared by multiple devices, MAC sub-layer of data link layer helps to determine which device has control over the channel at a given time.

access control

The Physical layer also defines the transmission rate i.e. the number of bits sent per second.

bit rate control

The physical layer provides the synchronization of the bits by providing a clock. This clock controls both sender and receiver thus providing synchronization at bit level.

bit synchronization

Physical layer PDU

bits

The physical layer contains information in the form of:

bits

Reduces the number of bits that need to be transmitted on the network:

compression

Connection Oriented Service three-phase process include

connection establishment data transfer termination / disconnection

services provided by transport layer

connection oriented service connection less service

Application layer PDU

data

Presentation layer PDU

data

Session layer PDU

data

When a packet arrives in a network, it is the responsibility of ______ to transmit it to the Host using its MAC address.

data link layer

____responsible for the node to node delivery of the messages

data link layer

Presentation layer is responsible for

data translation

Transport layer also provides the acknowledgment of the successful ______ and _____ the data if an error is found.

data transmission re-transmits

The session layer allows two systems to start communication with each other in half-duplex or full-duplex:

dialog controller

functions of the Application layer are:

directory services

Connection less transmission, the receiver _______acknowledge receipt of a packet. This approach allows for much faster communication between devices. Connection oriented Service is more reliable than connection less Service.

does not

The network layer protocols determine which route is suitable from source to destination.

routing

The sender & receiver's IP address are placed in the header by _____

network layer

_________takes care of packet routing i.e. selection of the shortest path to transmit the packet, from the number of routes available.

network layer

_______works for the transmission of data from one host to the other located in different networks.

network layer

Network layer PDU

packet

Segment in Network layer is referred as

packet

After creating frames, Data link layer adds physical addresses (MAC address) of sender and/or receiver in the header of each frame.

physical addressing

The physical layer is responsible for the actual ______ between the devices.

physical connection

The lowest layer of the OSI reference model is the

physical layer

When receiving data, this layer will get the signal received and convert it into 0s and 1s and send them to the Data Link layer, which will put the frame back together.

physical layer

Hub, Repeater, Modem, Cables are:

physical layer devices

Physical layer specifies the way in which the different, devices/nodes are arranged in a network i.e. bus, star or mesh topolgy.

physical topologies

At receiver's side: Transport Layer reads the ____ from its header and forwards the ____ which it has received to the respective application. It also performs _____and ____ of the segmented data.

port number data sequencing reassembling

The data from the application layer is extracted at the ______layer and manipulated as per the required format to transmit over the network.

presentation

Connection Oriented transmission, the receiving device sends an acknowledgment, back to the source after a packet or group of packet is received. This type of transmission is ____and ______.

reliable secure