Module 1: Networking Fundamentals

Basahin nyo na lang yung chart ng special addresses sa pages 73 to 75

Open Systems Interconnect/ion

created in 1984 by ISO (International Organization for Standardization)

ISO

International Organization for Standardization

Reference Model

a theoretical foundation for understanding network communication

OSI REFERENCE MODEL

It is divided into seven layers that work together to carry out specialized network functions, allowing for a more systematic approach to networking

Physical Layer

Responsible for moving individual bits from one device to the next device.

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

Data Link Layer

Responsible for moving frame from one hop to next hop.

Data Link Layer

it is the responsibility of this layer to transmit it to the Host using its MAC address.

Network Layer

Responsible for delivery of individual packet from source to destination.

Network Layer

The sender and receiver's IP address are placed in the header by this layer

Transport Layer

Responsible for process to process delivery.

Transport Layer

This layer accepts the message from the (session) layer and breaks the message into smaller units.

Session Layer

It stablish, maintain, synchronize, and terminate the interaction between sender and receiver.

Presentation Layer

Take care of syntax and semantics of the information exchange between two communication system.

Application Layer

Responsible for providing services to the user.

Bit, Symbol

PDU (Protocol Data Unit) of the Physical Layer

Frame

PDU (Protocol Data Unit) of the Data Link Layer

Packet

PDU (Protocol Data Unit) of the Network Layer

Segment, Datagram

PDU (Protocol Data Unit) of the Transport Layer

Data/ Message

PDU (Protocol Data Unit) of the Session, Presentation, and Application Layer

Data flows through the OSI model in a step-by-step process:

• Application Layer: Applications create the data.

• Presentation Layer: Data is formatted and encrypted.

• Session Layer: Connections are established and managed.

• Transport Layer: Data is broken into segments for reliable delivery.

• Network Layer: Segments are packaged into packets and routed.

• Data Link Layer: Packets are framed and sent to the next device.

• Physical Layer: Frames are converted into bits and transmitted physically.

End Device

a network-enabled hardware device that serves as either the source or destination of data transferred through a network.

End Device

workstation, laptop, desktop computer, printer, scanner, tablet, or cell phone

Intermediary Device

the ones that connect end devices and allow data transmission on a network.

Intermediary Device

hubs, bridges, switches, routers, repeaters, gateways, firewalls, or access points

Client – Server Network

Computer networks that employ a dedicated computer to store data, manage/provide resources, and control user access (server).

Client – Server Network

follows request-response pattern

Server

connects all the other computers in the network by acting as a hub.

Server

a computer or system that provides resources, data, services, or programs to other computers, known as clients, over a network

Client

any computer hardware or software device that requests access to a service provided by a server.

Client

typically seen as the requesting program or user in a client-server architecture

Peer-to-Peer Network

Defined as a network where all nodes, known as peers, interact cooperatively without a distinction between clients and servers, sharing resources and self-organizing into network topologies without the need for a centralized server

Peer

a node that provides the same functionality as another

Peer

a device that can function as a client or a server

IEEE

Institute of Electrical and Electronics Engineers

IEEE (Institute of Electrical and Electronics Engineers) 802

A collection of networking standards that cover the physical and data link layer specifications for technologies such as Ethernet and wireless

IEEE 802.1

Higher Layer LAN Protocols Working Group

IEEE 802.3

Ethernet (copper/ fiber optic)

IEEE 802.11

Wireless LAN (WLAN) & Mesh (Wi-Fi certification)

IEEE 802.15

Wireless PAN (Bluetooth/ infrared)

Personal Area Network

PAN

• connects electronic devices within a user's immediate area

• Bluetooth and Infrared

IEEE 802.5 – Token Ring

a data link for a local area network in which all devices are connected in a ring or star topology and pass one or more tokens from host to host.

token

• is passed between nodes to authorize that node to communicate

• is the symbol of authority for control of the transmission line.

Multistation access unit (MSAU)

Intermediary device for token ring.

IEEE 802.3

• Discovered in 1980 by Robert Metcalfe

• Standardized in 1983

LAN

• Local Area Network

• collection of devices connected together in one physical location, such as a building, office, or home

• Ethernet and WiFi

MAN

• Metropolitan Area Network

• a computer network that interconnects users with computer resources in a geographic region of the size of a metropolitan area

• Backbone network/ Access Network

WAN

• Wide Area Network

• a network that extends over a large geographic area, connecting multiple LANs

• Internet

Switch

only used for interconnecting devices

Router

necessary for an Internet connection

Router

refers to networking equipment moving data packets from one computer network to another.

Router

It operates at layer 3 of the Open Systems Interconnection stack and allows several devices to use the same internet connection.

Router

It also manages traffic between the computer networks by forwarding data packets to their specified Internet Protocol addresses

Router

use dynamic routing algorithms to determine the best path across the internetwork, thus minimizing traffic load

Router

they are interoperable with other networking devices, such as modems, one may use routers in together with those other devices.

Router

They are relatively slow as they process data packets at three layers.

Switch

• It works at layer 2 of the Open Systems Interconnection model, which is the data link layer.

• It receives data packets and sends them to the correct device.

Switch

When a data packet enters this, it reads the header to find its Media Access Control address and determine its destination

Switch

• Provide faster data transfer rates, resulting in better network performance.

• They can establish a direct connection with workstations.

Switch

• They are expensive.

• Broadcast/ multicast traffic can be problematic.

Switch

• direct path

• improved speed

• scalability

Router

• connect to different networks (interoperable)

• firewall and routing

• IP Addressing

• Routing

• Logical Addressing

Main Functions of Network layer

Hostname

a unique label assigned to a device connected to a computer network

• A unique name given to a device on the network

Physical address

A MAC (Media Access Control) address identifies network devices locally

Logical address

IP addresses are primarily used to identify a node's connectivity to a network.

IP Address

A unique number assigned to a device on a network

MAC Address

A unique hardware address of the network interface

IPV4

32 bits in length and gives us a maximum of 2³² addresses

IP Address

two parts: a network identifier and a host identifier.

Subnet masks

clarify which part of the address is the network ID and which is the host ID.

default gateway

is the path used to pass information when the device doesn't know where the destination is

Domain Name System (DNS)

is the phonebook of the Internet, it is managing the mapping between names (website) and numbers (IP address)

Domain Name System (DNS)

servers translate requests for names into IP addresses, controlling which server an end user will reach when they type a domain name into their web browser

Binary notation

01110101.10010101.00011101.00000010

Dotted-decimal notation

117.149.29.2

Octet

a unit of digital information in computing and telecommunications that consists of eight bits

Classful Addressing

• An IPv4 addressing architecture that divides addresses into five groups (class)

• Each class had a fixed range of addresses and a default subnet mask.

Class A

• the first bit of the first octet is always '0'.

• The first 8 bits or the first octet denote the network portion and the rest 24 bits or the 3 octets belong to the host portion.

1.0.0.0 to 126.255.255.255

the actual range of class A addresses

Class B

• the first octet would always start with '10'.

• The first 16 bits or the first two octets denote the network portion and the remaining 16 bits or two octets belong to the host portion.

128.0.0.0 to 191.255.255.255

class B addresses range

Class C

• the first octet would always start with '110'.

• The first 24 bits or the first three octets denote the network portion and the rest 8 bits or the remaining one octet belong to the host portion.

192.0.0.0 to 223.255.255.255

class C addresses range

Class D

a specific type of IP address labeling a network location that is used to multicast data packets within a network

multicast

is a type of group communication where data transmission is addressed to a group of destination computers simultaneously

224.0.0.0 to 239.255.255.255

Class D range

Class E

• addresses are reserved for research purposes and future use.

• The first octet in a class E address starts with '1111'.

240.0.0.0 to 255.255.255.255

class E addresses range

Internet Engineering Task Force (IETF)

is a standards organization for the Internet and is responsible for the technical standards that make up the Internet protocol suite.

CIDR

Unicast

a one-to-one transmission from one point in the network to another point

Multicast

a type of group communication where data transmission is addressed to a group of destination computers simultaneously

Multicast

can be one-to-many or many-to-many distribution

Network address

used to distinguish a network that has its own hosts and addresses (first address)

Broadcast addresses

used to transmit to all devices connected to a multiple-access communications network (last address)

Classless Addressing

CIDR was introduced to address the shortcomings of classful addressing and to allow more efficient allocation of IP addresses.

CIDR

Classless Inter-Domain Routing

• how IP addresses are allocated

prefix length

specifies the number of bits in the network portion of the address, offering more flexibility.

Variable-Length Subnet Mask (VLSM)

• technique, which changes the ratio between network and host address bits in an IP address

• allows networks to use subnet masks of varying lengths, accommodating networks of different sizes within the same address space.