Network Topology, Devices, OSI TCP/IP

 Network:- Group of Computer connected with each other Through any medium( wire/ wireless)

Computer Network Architecture : ( physical and Logical design of Software and Hardware , Protocol and media of transmission.)

    Two Types

    1. Peer to Peer ( connect with equal Privilege )

    2. Client Server Network. (Client Access data from server)

Network Devices :-

1. Hub

2.Switch

3. Router : (Network layer, packets )

4. Modem (H/W device to allow to connect Computer to Internet over telephone line)

DAY 2 *********************************

Types of Network (According to size)

1. LAN ( Local Area Network ) - (Building , office, - connect ( twisted pair & Coaxial Cable)

2.PAN ( Personal Area Network ):( Individual Person, range( 10 Meter or 30 Feet) - Idea by Thomas Zimmerman, 

3.MAN (Metropolitan Area network) : Connect LAN ,Protocols ( RS-232, Frame Relay, ATM , ISDN, ADSL ) Example :- Banks in City,

4.WAN(Wide Area Network) : State, Countries, 

Internet Woks: Two or more Network LAN or WAN connected 

    1. Extranet : use of MAN & WAN

    2. Intranet : (Organization employee access, to share data )

Topology : Physical topology is the Geometric representation of all the nodes.

    1.BUS  ( System is connected though single (Backbone ) cable, Topology use (802.3(ethernet) & 802.4 Standard and most common method CSMA (Carrier Sense Multiple Access) control the data flow and maintain Integrity. the packet do not loss , for handling the problem.

        CSMA CD :- (Collision Detection) if it detect collision it stop sending data, it work Recovery after collision.

        CSMA CA:-(Collison Avoidance ) is detect collision so it wait when it free.

    2. RING : -  Both ends are connected , data flow in one direction, data flow next node, flow the Clockwise direction, it use Token passing one node to another node.

    3. TREE : Combination of Bus topology and Star Topology,

    4. STAR :- Every nodes connect to Central Hub, (Server -Client) , Coaxial Cable and RJ- 45 Cable, Hub & Switch are mainly use, 

    6. MESH : System are connected each other, Number of Cable = (n*(n-1))/2 

    7. HYBRID :- Combination of various Topology,

    DAY - 3 ****************************************

    TRANSMISSION MODE :- Device is transmitted data one device to another devices.

    1. Simplex :- Unidirectional , the data flow in one direction. (ex. Keyboard , Monitor)

    2. Half Duplex :- Direction Can reversed , Message flow both direction but not same time. Ex. - Walkie -talkie  

    3. Full Duplex :- The flow bi-directional , the data flow both direction, EX- Telephone Network.

OSI ( Open system Interconnection - ( Reference Model to data(information) move one system s/w to Hardware and to the other Hardware to software application 

    * Seven Layer

    * Model Developed by International Organization for Standardization (ISO )    IN 1984.

    1. Application layer: ( Provide Service to User)

    * FTAM ( file transfer access and Management  * Mail Service 

    2.Presentatio Layer : ( Translation , Compression, Encryption)

        * data  format changes and it is also called Syntax Layer

        *Encoding 

    3. Session Layer : (establish, Manage , Terminate Session(Time))

        

    4.  Transport layer : (Reliable Message Delivery )

         * No Duplication of data ensures

         *Transfer Data Completely 

        * Convert Data into Segment

        * End to End layer Provide point to point Connection

        *Transmission Control Protocol -Maintain Connection Between Host, and ensure correct order of data at the receiving end.

        *User Datagram Protocol :- Unreliable Protocol

        * Responsible for error control to receive data error free .

    5. Network Layer :( Moving packet to source to Destination)

         * Track the Location of the Device

         *Determine Best Path to move data from source to destination

         *Routing Service with Internetwork

        * IPV6 and IPV4 

        * convert data Segment to packets 

    6. Data Link Layer : (Error Free data transfer)

        * Transfer error free data Frame

        *Framing  ( Header + Packet + Trailer)

        *Add destination address in the Header

        * Error Control - Cyclic Redundancy Check, 

    7. Physical Layer : (Bits  Transmit )

        *Bits Transfer one node to another.

        *Simplex , Half-duplex, Full duplex

        * Topology 

        

DAY - 4 ********************************************

TCP /IP 

        1. Network Access Layer

            *Physical and Data Link Layer

        2. Internet Layer :(Network Layer ) 

            * Responsible for Packets
            *IP Address

            * Data encapsulation

            * Routing

            * ARP (Address Resolution Protocol)- Find Physical Address form the IP Address.   

                      ** ARP request ("sender want to know the physical Address) 

                      **ARP reply ("Recipient only send the Physical Address ")

           *ICMP (Internet Control Message Protocol -,Mechanism to send datagram Problem back to the sender. 

                    ** ICMP Test ("test Destination is reachable or not ")

                    **ICMP Reply("Check destination Device is responding or not)

    3. Transport Layer  : Reliable , Flow Control, Correction data .    

             * User Data Gram Protocol :-Connection less service in end to end delivery Transmission, it discover error ,ICMP protocol report error to the sender.

               *Transmission Control Protocol(TCP) :create virtual Circuit between sender and receiver and (it active for duration of timing.) (it Detect error and retransmit the damaged frames, )

4. Application Layer :- Handling High level Protocol,     

            *HTTP : Hyper Text Transfer Protocol (allow data to access data over internet)

            *SNMP :- Simple Network Management Protocol (Help to manage the device using Internet TCP/IP Protocol suite)

            * DNS : Domain Name System( Help to get address by name instead of address) 

        * TELNET : Terminal Network (Connection between Local computer to the remote Computer)

        *FTP (File Transfer Protocol ) Transfer the file from one computer to another computer