Module-1.pdfbasic networking basic networking

Introduction
• Present era - data and information-centric operations.
• The quality of any particular information is as good as the variety and
strength of the data that generates this information.
• The speed at which data is updated to all members of a team (which may be
a group of individuals, an organization, or a country) dictates the advantage
that the team has over others in generating useful information from the
gathered data.
• Today’s world relies heavily on data and networking

Introduction (Cont…)
• Networking refers to the linking of computers and communication
network devices (also referred to as hosts), and are separated by unique
device identifiers.
• These hosts may be connected by a single path or through multiple
paths for sending and receiving data.
• The data transferred between the hosts may be text, images, or videos,
which are typically in the form of binary bit streams

Network Types
• Computer networks are classified according to various parameters:
1) Type of connection
2) physical topology and
3) reach of the network
• These classifications are helpful in deciding the requirements of a network
setup and provide insights into the appropriate selection of a network type
for the setup

I. Connection types
• Depending on the way a host communicates with other hosts
1. Point-to-point and
2. Point-to-multipoint
1. Point-to-point:
o Point-to-point connections are used to establish direct connections between two hosts.
o These networks were designed to work over duplex links and are functional for both
synchronous as well as asynchronous systems.

2. Point-to-multipoint:
oMore than two hosts share the same link
oThis type of configuration is similar to the one-to-many connection type
oThe channel is shared between the various hosts

(a) Point-to-point (b) Point-to-multipoint

II. Physical topology
• Depending on the physical manner in which communication paths between
the hosts are connected, computer networks can have the following four
broad topologies:
1. Star
2. Mesh
3. Bus and
4. Ring

1. Star Topology
• Every host has a point-to-point link to a central controller or hub.
• The hosts cannot communicate with one another directly; they can
only do so through the central hub.
• The hub acts as the network traffic exchange.
• For large-scale systems, the hub, essentially, has to be a powerful
server to handle all the simultaneous traffic flowing through it.
• As there are fewer links, this topology is cheaper and easier to set
up.

• Advantages of the star topology are easy installation and the ease of
fault identification within the network. If the central hub remains
uncompromised, link failures between a host and the hub do not have
a big effect on the network, except for the host that is affected.
• Disadvantage of this topology is the danger of a single point of failure.
If the hub fails, the whole network fails

2. Mesh Topology
• In a mesh topology, every host is connected to
every other host using a dedicated link.
• For n hosts in a mesh, there are a total of
n(n−1)/2 dedicated full duplex links between
the hosts. This massive number of links makes
the mesh topology expensive.

• Advantages:
• Robustness and resilience of the system. Even if a link is down or broken, the
network is still fully functional as there remain other pathways for the traffic to
flow through
• The security and privacy of the traffic as the data is only seen by the intended
recipients and not by all members of the network.
• The reduced data load on a single host, as every host in this network takes care
of its traffic load

3. Bus Topology
• A bus topology follows the point-to-multipoint
connection.
• A backbone cable or bus serves as the primary traffic
pathway between the hosts.
• The hosts are connected to the main bus employing
drop lines or taps
• Ease of installation

• There is a restriction on the length of the bus and the number of hosts
that can be simultaneously connected to the bus due to signal loss over
the extended bus.
• The bus topology has a simple cabling procedure in which a single bus
(backbone cable) can be used for an organization.
• Multiple drop lines and taps can be used to connect various hosts to
the bus, making installation very easy and cheap.
• However, the main drawback of this topology is the difficulty in fault
localization within the network

4. Ring Topology
• Works on the principle of a point-to-point connection.
• Each host is configured to have a dedicated point-to-point
connection with its two immediate neighboring hosts on
either side of it through repeaters at each host.
• The repetition of this system forms a ring.
• The repeaters at each host capture the incoming signal
intended for other hosts, regenerates the bit stream, and
passes it onto the next repeater.

Network Reachability
• Computer networks are divided into four broad categories based on
network reachability:
1. Personal area networks (PAN)
2. Local area networks(LAN)
3. Wide area networks(WAN) and
4. Metropolitan area networks(MAN)

Personal area networks (PAN)
• Restricted to individual usage
• PANs are wireless networks, which make use of low-range and low-power
technologies such as Bluetooth.
• The reachability of PANs lies in the range of a few centimeters to a few
meters.
• Data rate in range of few Kbps.
• E.g. Connected wireless headphones, wireless speakers, laptops,
smartphones

Local area networks(LAN)
• Collection of hosts linked to a single network through wired or wireless connections.
• LANs are restricted to buildings, organizations, or campuses.
• Typically, a few leased lines connected to the Internet provide web access to the whole
organization or a campus;
• The lines are further redistributed to multiple hosts within the LAN enabling hosts
• The present-day data access rates within the LANs range from 100 Mbps to 1000 Mbps, with
very high fault-tolerance levels.
• Commonly used network components in a LAN are servers, hubs, routers, switches, terminals,
and computers

Wide area networks(WAN)
• Connect diverse geographic locations.
• They are restricted within the boundaries of a state or country.
• The data rate of WANs is in the order of a fraction of LAN’s data rate – 10 to 100Mbps.
• Typically, WANs connecting two LANs or MANs may use public switched telephone
networks (PSTNs) or satellite-based links.
• Due to the long transmission ranges, WANs tend to have more errors and noise during
transmission and are very costly to maintain.
• The fault tolerance of WANs are also generally low

Metropolitan area networks(MAN)
• The reachability of a MAN lies between that of a LAN and a WAN
• MANs connect various organizations or buildings within a given geographic location or
city.
• An excellent example of a MAN is an Internet service provider (ISP) supplying Internet
connectivity to various organizations within a city.
• As MANs are costly, they may not be owned by individuals or even single organizations.
• Typical networking devices/components in MANs are modems and cables.
• Data rate – 1Gbps to 100 Gbps.
• MANs tend to have moderate fault tolerance levels.

Layered Network Models
• The intercommunication between hosts in any computer network is
built upon the premise of various task-specific layers.
• Traditional layered network models:
1. OSI reference model
2. Internet protocol suite

OSI Model
• Open Systems Interconnection (OSI) model describes seven layers that
computer systems use to communicate over a network.
• The ISO-OSI model is a conceptual framework that partitions any
networked communication device into seven layers of abstraction,
each performing distinct tasks based on the underlying technology and
internal structure of the hosts

1. Physical Layer
• First/Lowest layer of the OSI model.
• Responsible for physical connection between devices.
• Responsible for electrical and mechanical operations of the host at physical
level: signal generation, signal transfer, voltages, the layout of cables,
physical port layout, line impedances, and signal loss.
• Responsible for the topological layout of the network (star, mesh, bus, or
ring), communication mode (simplex, duplex, full duplex), and bit rate
control operations

2. Data Link Layer
• Second layer of the model.
• Responsible for the node-to-node delivery of the message.
• The main function of this layer is to make sure data transfer is error-free from one
node to another, over the physical layer
• When a packet arrives in a network, it is the responsibility of DLL to transmit it to
the Host using its MAC address.
• Two sublayers-
1.Logical Link Control (LLC)
2.Media Access Control (MAC)

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

Network Layer
• Media layer – layer 3.
• Works for the transmission of data from one host to the other located
in different networks.
• It also takes care of packet routing i.e., selection of the shortest path to
transmit the packet, from the number of routes available.
• The sender & receiver’s IP addresses are placed in the header by the
network layer.
• Functions – addressing, sequencing of packets, congestion control,
error handling, and Internetworking.
• The protocol data unit associated with this layer is referred to as a
packet.

Transport Layer
• Layer 4 - host layer.
• Tasks - end-to-end error recovery and flow control to achieve a transparent transfer of
data between hosts.
• This layer is responsible for keeping track of acknowledgments during variable-length
data transfer between hosts.
• In case of loss of data, or when no acknowledgment is received, the transport layer
ensures that the particular erroneous data segment is re-sent to the receiving host.
• The protocol data unit associated with this layer is referred to as a segment or datagram

Session Layer
• It is responsible for establishing, controlling, and termination of
communication between networked hosts, authentication and security.
• The session layer sees full utilization during operations such as remote
procedure calls and remote sessions.
• The protocol data unit associated with this layer is referred to as data.

Presentation Layer
• Host layer - layer 6.
• The data from the application layer is extracted here and manipulated as per
the required format to transmit over the network.
• Responsible for data format conversions and encryption tasks such that the
syntactic compatibility of the data is maintained across the network, for
which it is also referred to as the syntax layer.
• The protocol data unit associated with this layer is referred to as data.

Application Layer
• It is directly accessible by an end-user through software APIs (application
program interfaces) and terminals.
• Applications such as file transfers, FTP (file transfer protocol), e-mails, and other
such operations are initiated from this layer.
• The application layer deals with user authentication, identification of
communication hosts, quality of service, and privacy.
• The protocol data unit associated with this layer is referred to as data

Internet protocol suite
• The Internet protocol suite predates the OSI model and provides only four levels
of abstraction:
1. Link layer
2. Internet layer
3. Transport layer and
4. Application layer.
• This collection of protocols is commonly referred to as the TCP/IP protocol suite
as the foundation technologies of this suite are Transmission Control Protocol
(TCP) and Internet Protocol (IP)

Link Layer:
• First and base layer of the TCP/IP protocol suite - Network Interface Layer.
• This layer is synonymous with the collective physical and data link layer of
the OSI model.
• It enables the transmission of TCP/IP packets over the physical medium.
• According to its design principles, the link layer is independent of the
medium in use, frame format, and network access, enabling it to be used
with a wide range of technologies such as the Ethernet, wireless LAN, and
the asynchronous transfer mode (ATM).

Internet Layer:
• Layer 2 of the TCP/IP protocol suite is synonymous to the network layer of
the OSI model.
• It is responsible for addressing, address translation, data packaging, data
disassembly and assembly, routing, and packet delivery tracking operations.
• Some core protocols associated with this layer are address resolution
protocol (ARP), Internet protocol (IP), Internet control message protocol
(ICMP), and Internet group management protocol (IGMP).

Transport Layer:
• Layer 3 of the TCP/IP protocol suite is functionally synonymous with the transport
layer of the OSI model.
• Functions - error control, flow control, congestion control, segmentation, and
addressing in an end-to-end manner;
• It is also independent of the underlying network.
• Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) are the
core protocols upon which this layer is built, which in turn enables it to have the
choice of providing connection-oriented or connectionless services between two
or more hosts or networked devices.

Application Layer:
• Layer 4 of the TCP/IP protocol suite are synonymous with the collective
functionalities of the OSI model’s session, presentation, and application layers.
• This layer enables an end-user to access the services of the underlying layers and
defines the protocols for the transfer of data.
• Hypertext transfer protocol (HTTP), file transfer protocol (FTP), simple mail
transfer protocol (SMTP), domain name system (DNS), routing information
protocol (RIP), and simple network management protocol (SNMP) are some of the
core protocols associated with this layer.

Introduction
• The present-day Internet allows massively heterogeneous traffic through it.
• This network traffic consists of images, videos, music, speech, text, numbers, binary
codes, machine status, banking messages, data from sensors and actuators, healthcare
data, data from vehicles, home automation system status and control messages, military
communications, and many more.
• This huge variety of data is generated from a massive number of connected devices,
which may be directly connected to the Internet or connected through gateway devices.

• 10-year global trend and projection of connected devices (statistics sourced from
the Information Handling Services)

The Internet of Things (IoT) is the network of physical objects that
contain embedded technology to communicate and sense or interact
with their internal states or the external environment.“
- Gartner Research

• IoT is an anytime, anywhere, and anything network of
Internet-connected physical devices or systems capable of
sensing an environment and affecting the sensed
environment intelligently.
• This is generally achieved using low-power and low-form-
factor embedded processors on-board the “things”
connected to the Internet.

IoT systems can be characterized by the following features:
• Associated architectures, which are also efficient and scalable.
• No ambiguity in naming and addressing.
• Massive number of constrained devices, sleeping nodes, mobile devices, and non-
IP devices.
• Intermittent and often unstable connectivity.
IoT is speculated to have achieved faster and higher technology acceptance as compared
to electricity and telephony.

The compound annual growth rate (CAGR) of the IoT
market
The IoT market share across various industries

Evolution of IoT
The sequence of technological developments leading to the shaping
of the modern-day IoT

ATM
• ATMs or automated teller machines are cash distribution machines, which are linked
to a user’s bank account.
• ATMs dispense cash upon verification of the identity of a user and their account
through a specially coded card.
• The central concept behind ATMs was the availability of financial transactions even
when banks were closed beyond their regular work hours.
• These ATMs were ubiquitous money dispensers.
• The first ATM became operational and connected online for the first time in 1974

Web
• World Wide Web is a global information sharing and communication
platform.
• The Web became operational for the first time in 1991.
• Since then, it has been massively responsible for the many revolutions
in the field of computing and communication

Smart Meters
• The earliest smart meter was a power meter, which became operational
in early 2000.
• These power meters were capable of communicating remotely with the
power grid.
• They enabled remote monitoring of subscribers’ power usage and
eased the process of billing and power allocation from grids.

Digital Locks
• Digital locks can be considered as one of the earlier attempts at
connected home-automation systems.
• Present-day digital locks are so robust that smartphones can be used to
control them.
• Operations such as locking and unlocking doors, changing key codes,
including new members in the access lists, can be easily performed,
and that too remotely using smartphones

Connected Healthcare
• Healthcare devices connect to hospitals, doctors, and relatives to alert
them of medical emergencies and take preventive measures.
• The devices may be simple wearable appliances, monitoring just the
heart rate and pulse of the wearer, as well as regular medical devices
and monitors in hospitals.
• The connected nature of these systems makes the availability of
medical records and test results much faster, cheaper, and convenient
for both patients as well as hospital authorities.

Connected Vehicles
• Connected vehicles may communicate to the Internet or with other
vehicles, or even with sensors and actuators contained within it.
• These vehicles self-diagnose themselves and alert owners about
system failures.

Smart Cities
• This is a city-wide implementation of smart sensing, monitoring, and
actuation systems.
• The city-wide infrastructure communicating amongst themselves
enables unified and synchronized operations and information
dissemination.
• Some of the facilities which may benefit are parking, transportation,
and others.

Smart Dust
• These are microscopic computers.
• Smaller than a grain of sand each, they can be used in numerous
beneficial ways, where regular computers cannot operate.
• For example, smart dust can be sprayed to measure chemicals in the
soil or even to diagnose problems in the human body.

Smart Factories
• These factories can monitor plant processes, assembly lines, distribution lines,
and manage factory floors all on their own.
• The reduction in mishaps due to human errors in judgment or unoptimized
processes is drastically reduced
UAVs
• UAVs or unmanned aerial vehicles have emerged as robust publicdomain
solutions tasked with applications ranging from agriculture, surveys,
surveillance, deliveries, stock maintenance, asset management, and other tasks.

Technological interdependencies of IoT with
other domains and networking paradigms
M2M - Machine-to-Machine
CPS - Cyber Physical System
IoE – Internet of Environment
IoP – Internet of People

M2M
• The M2M or the machine-to-machine paradigm signifies a system of
connected machines and devices, which can talk amongst themselves
without human intervention.
• The communication between the machines can be for updates on
machine status (stocks, health, power status, and others), collaborative
task completion, overall knowledge of the systems and the
environment, and others.

CPS
• The CPS or the cyber physical system paradigm insinuates a closed
control loop—from sensing, processing, and finally to actuation—
using a feedback mechanism.
• CPS helps in maintaining the state of an environment through the
feedback control loop, which ensures that until the desired state is
attained, the system keeps on actuating and sensing.
• Humans have a simple supervisory role in CPS-based systems; most
of the ground-level operations are automated.

IoE
• The IoE paradigm is mainly concerned with minimizing and even
reversing the ill-effects of the permeation of Internet-based
technologies on the environment.
• The major focus areas of this paradigm include smart and sustainable
farming, sustainable and energy-efficient habitats, enhancing the
energy efficiency of systems and processes, and others.
• In brief, we can safely assume that any aspect of IoT that concerns and
affects the environment, falls under the purview of IoE

Industry 4.0
• Industry 4.0 is commonly referred to as the fourth industrial revolution pertaining
to digitization in the manufacturing industry.
• The previous revolutions chronologically dealt with mechanization, mass
production, and the industrial revolution, respectively.
• This paradigm strongly puts forward the concept of smart factories, where
machines talk to one another without much human involvement based on a
framework of CPS and IoT.
• The digitization and connectedness in Industry 4.0 translate to better resource and
workforce management, optimization of production time and resources, and better
upkeep and lifetimes of industrial systems.

IoP
• IoP is a new technological movement on the Internet which aims to
decentralize online social interactions, payments, transactions, and
other tasks while maintaining confidentiality and privacy of its user’s
data.
• A famous site for IoP states that as the introduction of the Bitcoin has
severely limited the power of banks and governments, the acceptance
of IoP will limit the power of corporations, governments, and their spy
agencies

IoT versus M2M
• M2M - communications and interactions between various machines
and devices.
• These interactions can be enabled through a cloud computing
infrastructure, a server, or simply a local network hub.
• M2M collects data from machinery and sensors, while also enabling
device management and device interaction.
• Telecommunication services providers introduced the term M2M, and
technically emphasized on machine interactions via one or more
communication networks (e.g., 3G, 4G, 5G, satellite, public
networks).
• M2M is part of the IoT and is considered as one of its sub-domains.

• M2M standards occupy a core place in the IoT landscape.
• However, in terms of operational and functional scope, IoT is vaster
than M2M and comprises a broader range of interactions such as the
interactions between devices/things, things, and people, things and
applications, and people with applications.
• M2M enables the amalgamation of workflows comprising such
interactions within IoT.
• Internet connectivity is central to the IoT theme but is not necessarily
focused on the use of telecom networks.

IoT versus CPS
• Cyber physical systems (CPS) encompasses sensing, control,
actuation, and feedback as a complete package.
• In other words, a digital twin is attached to a CPS-based system.
• Digital twin is a virtual system–model relation, in which the system
signifies a physical system or equipment or a piece of machinery,
while the model represents the mathematical model or representation
of the physical system’s behavior or operation.
• Many a time, a digital twin is used parallel to a physical system,
especially in CPS as it allows for the comparison of the physical
system’s output, performance, and health.

• Based on feedback from the digital twin, a physical system can be
easily given corrective directions/commands to obtain desirable
outputs.
• In contrast, the IoT paradigm does not compulsorily need feedback or
a digital twin system.
• IoT is more focused on networking than controls.
• Some of the constituent sub-systems in an IoT environment may
include feedback and controls too.
• In this light, CPS may be considered as one of the sub-domains of IoT

IoT versus WoT
• Web of Things (WoT) paradigm enables access and control over IoT resources and
applications.
• These resources and applications are generally built using technologies such as
HTML 5.0, JavaScript, Ajax, PHP, and others.
• REST (representational state transfer) is one of the key enablers of WoT.
• The use of RESTful principles and RESTful APIs (application program interface)
enables both developers and deployers to benefit from the recognition, acceptance,
and maturity of existing web technologies without having to redesign and redeploy
solutions from scratch

• Still, designing and building the WoT paradigm has various adaptability and
security challenges, especially when trying to build a globally uniform WoT.
• As IoT is focused on creating networks comprising objects, things, people,
systems, and applications, which often do not consider the unification aspect
and the limitations of the Internet, the need for WoT, which aims to integrate
the various focus areas of IoT into the existing Web is really invaluable.
• Technically, WoT can be thought of as an application layer-based hat added
over the network layer.
• Scope of IoT applications is much broader.

Enabling IoT and the Complex Interdependence
of Technologies
• IoT paradigm into four planes:
1. Services
2. Local connectivity
3. Global connectivity, and
4. Processing

Service Plane
• Composed of two parts:
1. Things or devices and
2. Low-power connectivity
• IoT application requires the basic setup of sensing, followed by rudimentary
processing (often), and a low-power, low-range network, which is mainly
built upon the IEEE 802.15.4 protocol.
• The things - wearables, computers, smartphones, household appliances,
smart glasses, factory machinery, vending machines, vehicles, UAVs,
robots, and other such contraptions.

• Low-power connectivity - responsible for connecting the things in
local implementation, may be legacy protocols such as WiFi,
Ethernet, or cellular.
• Modern-day technologies are mainly wireless and often
programmable such as Zigbee, RFID, Bluetooth, 6LoWPAN, LoRA,
DASH, Insteon, and others.
• They are responsible for the connectivity between the things of the
IoT and the nearest hub or gateway to access the Internet.

Local Connectivity
• Responsible for distributing Internet access to multiple local IoT
deployments.
• This distribution may be on the basis of the physical placement of the
things, on the basis of the application domains, or even on the basis of
providers of services.
• Services such as address management, device management, security, sleep
scheduling, and others fall within the scope of this plane.
• This plane falls under the purview of IoT management as it directly deals
with strategies to use/reuse addresses based on things and applications.

Global Connectivity
• Plays a significant role in enabling IoT in the real sense by allowing for
worldwide implementations and connectivity between things, users,
controllers, and applications.
• This plane also falls under the purview of IoT management as it decides
how and when to store data, when to process it, when to forward it, and in
which form to forward it.
• The Web, data-centers, remote servers, Cloud, and others make up this
plane.

• The paradigm of “fog computing” lies between the planes of local
connectivity and global connectivity.
• It often serves to manage the load of global connectivity infrastructure
by offloading the computation nearer to the source of the data itself,
which reduces the traffic load on the global Internet.

Processing
• The members in this plane may be termed as IoT tools, simply because
they wring-out useful and human-readable information from all the
raw data that flows from various IoT devices and deployments.
• The various sub-domains of this plane include
• Intelligence
• Conversion (data and format conversion, and data cleaning),
learning (making sense of temporal and spatial data patterns)

• Cognition (recognizing patterns and mapping it to already known patterns),
algorithms (various control and monitoring algorithms)
• Visualization (rendering numbers and strings in the form of collective trends,
graphs, charts, and projections), and
• Analysis ((estimating the usefulness of the generated information, making
sense of the information with respect to the application and place of data
generation, and estimating future trends based on past and present patterns of
information obtained).
• Various computing paradigms such as “big data”, “machine
Learning”, and others, fall within the scope of this domain.

IoT Networking Components
• An IoT implementation is composed of several components, which may vary with their
application domains.
• The broad components that come into play during the establishment of any IoT network,
into six types:
1. IoT node
2.IoT router
3. IoT LAN
4.IoT WAN
5.IoT gateway, and
6.IoT proxy

A typical IoT network ecosystem highlighting the various networking
components— from IoT nodes to the Internet

IoT Node:
• The networking devices within an IoT LAN.
• Each of these devices is typically made up of a sensor, a processor, and a
radio, which communicates with the network infrastructure (either within
the LAN or outside it).
• The nodes may be connected to other nodes inside a LAN directly or by
means of a common gateway for that LAN. Connections outside the LAN
are through gateways and proxies.

IoT Router:
• An IoT router is a piece of networking equipment that is primarily
tasked with the routing of packets between various entities in the IoT
network;
• It keeps the traffic flowing correctly within the network.
• A router can be repurposed as a gateway by enhancing its
functionalities.

IoT LAN:
• The local area network (LAN) enables local connectivity within the
purview of a single gateway.
• Typically, they consist of short-range connectivity technologies.
• IoT LANs may or may not be connected to the Internet.
• Generally, they are localized within a building or an organization.

IoT WAN:
• The wide area network (WAN) connects various network segments such as
LANs.
• They are typically organizationally and geographically wide, with their
operational range lying between a few kilometers to hundreds of kilometers.
• IoT WANs connect to the Internet and enable Internet access to the segments
they are connecting.

IoT Gateway:
• An IoT gateway is simply a router connecting the IoT LAN to a WAN
or the Internet.
• Gateways can implement several LANs and WANs.
• Their primary task is to forward packets between LANs and WANs,
and the IP layer using only layer 3.

IoT Proxy:
• Proxies actively lie on the application layer and performs application
layer functions between IoT nodes and other entities.
• Typically, application layer proxies are a means of providing security
to the network entities under it ;
• It helps to extend the addressing range of its network.

Module-1.pdfbasic networking basic networking

More Related Content

Similar to Module-1.pdfbasic networking basic networking

More from ssuserc007ac

Recently uploaded

Module-1.pdfbasic networking basic networking