Class B Subnetting

Example:

                                       255.255.128.0  (/17)
Network Address:

                                        172.16.0.0 = Network Address
                                        255.255.0.0  = Subnet Mask

Subnet: 

                                        255.255.128.0 (/17)

                                        IIIIIIII.IIIIIII.I0000000.00000000
                 
Subnet:                            2x1=2


Host:                               2 power 15-2= 32,766 (7 bits in thirad octate and 8 bits in the 4 octate.

Valid Subnet:

Subnet                         0.0                                128.0
First Host                    0.1                                128.1
Last Host                    127.254                        255.254
Broadcast                    127.255                        255.255

Subnetting

Class                        Formet                                 Default Subnet Mask
A                      network.host.host.host                   255.0.0.0
B                      network.network.host.host             255.255.0.0
C                      network.network.network.host      255.255.255.0

Valid Subnet-   256-subnet mask=block size or increment number.  An example would be256-192=64 .  The block size of a 192 mask is always 64. start counting at '0' in block of 64 until you reach the subnet mask value and these are you subnets. 0,64,128,192.

Broadcast Address-  Now here the realy easy part since we counted our subnets it the last section as 0,64,128,and 192.  The broadcast address is always the number before need the subnets for example of '63' because the next subnet is 128 and so on and remember the broadcast address the last subnet is always 255.

Valid Host-  Valid host are numbers between the subnets omitting the all '0' ans '1s'.  For example: If 84 is the subnet number and 127 is the broadcast address. Then 65-126 is the valid host range.  It is always the number between the subnet address and the bradcast address.

Class C:

Example:  255.255.255.128 (/25)
                  IIIIIIII:IIIIIIII:IIIIIIII:I0000000

Since 128 is 10000000 in binary, there is only 1 bit for subneting and 7bits for hosts.  We are going to subnet the class C network address.

                 192.168.10.0      = network Address
                 255.255.255.128=Subnet Mask


How many Subnet

Since 128 is 1bit on (10000000) the answer would be 2x1=126hosts.

How many host per subnets?     

256-126=128, Remember willbe start at '0' and count in our block size.  So our subnets are 0,128.

What is the broadcast address for each subnet?

"The number right before the valuea of the next subnet is all host bits turned on and equal the broadcast address.  This way the valid hosts are obvious.  The following Table shows the '0' and 128 subnets.  The valid host ranges of each and the broadcast address of both subnets.

Subnets                   0                                                 128
First host                 1                                                 129
Last host                 126                                             254 
Broadcast host        127                                             255

folder sharing between computer

दोनों कंप्यूटर में ऐसा folder बनाना है /जिसकी सामग्री हम access चाहते है/ इसे कोई सुविधाजनक नाम देना है /  जैसे shared laptop folder और shared desktop folder / इस फोल्डर पर right mouse क्लिक करके properties पर क्लिक करे/ अब खुलने वाले dialog box में sharing tab को select करे /अब shared this folder को select करे / फिर shared desktop folder और shared laptop folder जैसा कोई नाम देदे / दूसरे कंप्यूटर में आपका folder shred folder के नाम से दिखाई देगा/
अब OK button दबाना है/

Check the workgroup in Window 7

start---------------------->controlpannel----------------------->network&internet

अब होमग्रुप पर  करे आपके नेटवर्क में मौजूद दूसरा कम्प्यूटर दिखाई देगा/

checking of workgroup in Window XP

My network place पर क्लिक करे / अब entire network पर क्लिक करे/ और अब window network पर double click करे /यहां पर workgroup का नाम दिखाई देगा / अतः दोनों कंप्यूटर कनेक्ट हो चुके है /

अब छोटा सा प्रोसेस बचता है / और यह है कम्प्यूटर की सामग्री को access करने का / उसके लिए नेटवर्क शेयरिंग सुविधा का इस्तेमाल करना होगा /

Create a Workgroup in Window 7

start--------------------->controlpannel------------------------->system&security system

अब change setting को क्लिक करे /

खुलने वाले डायलॉग बॉक्स में computer name tab पर जाय / और change button पर क्लिक करे / इससे computer name dialog box खुल जायगा / यहाँ पर  अपने कंप्यूटर का नाम दे दे /  जैसे home computer,

हमारे कंप्यूटर को जोड़ने वाले workgroup का नाम भी होना चाहिए / दोनों कंप्यूटर इसके सदस्य होंगे / workgroup का नाम भी होगा / जैसे - होम कंप्यूटर या माय नेटवर्क

यह  प्रोसेस दोनों कंप्यूटर में पूरी करे / अब ok बटन दबा दे/  दोनों कंप्यूटर एक बार रिस्टार्ट  होंगे / रिस्टार्ट होते ही नेटवर्क तैयार है/

Create the Workgroup in Window XP

start-------------------->control pannel------------------------>system

खुलने वाले डायलॉग बॉक्स में computer name tab पर जाय / और change button पर क्लिक करे / इससे computer name dialog box खुल जायगा / यहाँ पर  अपने कंप्यूटर का नाम दे दे /  जैसे home computer,

हमारे कंप्यूटर को जोड़ने वाले workgroup का नाम भी होना चाहिए / दोनों कंप्यूटर इसके सदस्य होंगे / workgroup का नाम भी होगा / जैसे - होम कंप्यूटर या माय नेटवर्क

यह  प्रोसेस दोनों कंप्यूटर में पूरी करे / अब ok बटन दबा दे/  दोनों कंप्यूटर एक बार रिस्टार्ट  होंगे / रिस्टार्ट होते ही नेटवर्क तैयार है/

IP configuration for Window 7

start----------->control pannel------------->network & internet

networking and sharing center पर जायें /  और left की ओर change adoptor setting पर क्लिक करे / और खुलने वाले पेज में local area networking का icon दिखाई देगा / इसपर right click करे /

अब प्रॉपर्टीज को सेलेक्ट करे / जिससे  लोकल   एरिया कनेक्शन  प्रॉपर्टीज  डायलॉग बॉक्स खुल   जाएगा /

अब  इंटरनेट प्रोटोकॉल (TCP/IP )  प्रॉपर्टीज डायलॉग बॉक्स खुल जाएगा /

 दोनों ही  कंप्यूटर में "use the following IPaddressing"  को चुने और हर कंप्यूटर का unique IP Addressing  टाइप करे / IP address  कंप्यूटर  की डिजिटल  पहचान होती है /

 "लोकल एरिया कनेक्शन " के लिए 192.168.1.x  IP एड्रेस का  यूज़ होता है/ जिसमे x  1  से 255 के   बीच कोई भी नंबर हो सकता है/

अपने एक कंप्यूटर का IP address 192.168.1.1 रख ले  और दूसरे का 192.168.1.2 रख ले /

IP address के नीचे subnet mask नामक बॉक्स दिखाई देगा / जिसमे 255.255.255.0  डालकर OK बटन दबा दे /यह प्रक्रिया दोनों कंप्यूटर में करनी है/

IP configuration for Window XP

start--------->Network Connection

"लोकल एरिया कनेक्शन "को ढूंढे और राइट क्लिक करे / अब प्रॉपर्टीज को सेलेक्ट करे / जिससे  लोकल   एरिया कनेक्शन  प्रॉपर्टीज  डायलॉग बॉक्स खुल   जाएगा /

अब  इंटरनेट प्रोटोकॉल (TCP/IP )  प्रॉपर्टीज डायलॉग बॉक्स खुल जाएगा /

 दोनों ही  कंप्यूटर में "use the following IPaddressing"  को चुने और हर कंप्यूटर का unique IP Addressing  टाइप करे / IP address  कंप्यूटर  की डिजिटल  पहचान होती है /

 "लोकल एरिया कनेक्शन " के लिए 192.168.1.x  IP एड्रेस का  यूज़ होता है/ जिसमे x  1  से 255 के   बीच कोई भी नंबर हो सकता है/

अपने एक कंप्यूटर का IP address 192.168.1.1 रख ले  और दूसरे का 192.168.1.2 रख ले /

IP address के नीचे subnet mask नामक बॉक्स दिखाई देगा / जिसमे 255.255.255.0  डालकर OK बटन दबा दे /यह प्रक्रिया दोनों कंप्यूटर में करनी है/

Trusted and Untrusted Network

Trusted network s are defined as networks which share the same security poilicy and procedures.  Untrusted networks are the opposite of trusted networks, they do not follow the same security policy.  Untrusted networks, security policies are unknown and unpredictable.  The most secure policy is to allow connections to trusted networks only.

Virtual Private Network

A Virtual private network is a network that uses a public telecommunication infrastructure, such as the internet, to provide remote office es or individual users with secure access to their organization’s network.  A virtual private network can be contrasted with an expensive system of owned or leased lines That can only be used by one organization.  The goal of a VPN is to provide the organization with the same capabilities, but at a much lower cost.

A VPN work s by using the shared public infrastructure while maintaining privacy through security procedures and tunneling protocols such as the Layer Two Tunneling Protocol (L2TP).

In effect, the protocols, by encryption data at the sending end and decrypting I at the receiving end, send he data through a “tunnel” that cannot be “entered” by data that is not properly encrypted.  An additional level of security involves encrypting not only the data, but also the originating and receiving network addresses.

Star Network

In a star network cable segments to a central connection unit or hub connect all computers.
Chief advantage of star topology over the bus topology over the bus topology is that, if a cable segment is broken, onlyonnected to the hub on that cable segment is affected.

Attachment Unit Interface (AUI)

Connector commonly are used with thick Ethernet cabling.  These device used a DB15 connecor to link o the network card.

Hardware utilized in a Bus Topology Network

Both thin Ethernet and thick Ethernet require the following additional network hardware to link the host.

1. BNC Connector
2. Terminator
3. AUI Connector

British Novel Connector-  BNC connector enable the various thin-net Coaxial cable segments to interconnect each host has a T-connector that is used to link the cable segment to a host computer.

Wiring standard in a Bus Network

Computer network commonly are linked using network cabling.  The following are two wiring standards for communications on a bus network.

10Base2-  Also known  as thin Ethernet.  It allow network segment up o 185 meter on coaxial cable.

10Base5-  Also known as thick Ethernet, it allows network segments up o 500 meter in coaxial cable.

Local Area Network

There are basic type of local area network.

1. Peer to Peer
2. Server Based

Peer to Peer-  Peer to Peer network operate with no dedicated server on the network.  Each host functions as both a client and a server.  The user at each host determine what information or peripherals he is willing to share with the other members of the network.  Peer to Peer network generally are related to smaller organizations they do not scale will to larger ones.

Server Based Network-  At least one host is dedicated to server functionality.  Client computer do not share any information with other computer.  All data is stored on the central server .  Most corporate networks are based on this methodology.  Within a server based network, server can play several roles these roles include the following.

Directory Server-  These provide a central directory service for management of users groups and host object to allow for centralized authorization using the central directory.

Files and Print Server-  These provide a secure repository for all data.  They also can  manage point queues that provide access to network.  Searchable print resources.

Application Server-  These provide the server side of client/server application.  In a client/server environment, the client run a small version of the program that allow connectivity to the server.  The server side of the application is used to perform processor- intensive quires on behalf of the client.  Example of application server included Web server and database server.

Mail Server-  These provides electronics message capabilities for the clients of the network.

                                                                         or

A mail server is a program responsible for receiving routing and delivering e-mail message.

Security Server-  These provide security to the local network.  If it is connected to any larger networks such as the internet, security; server include firewalls and proxy servers.

Remote Access Server-  These enalble external data flow to occur between the network, or alternatively, use the technology known as tunneling or virtual private networks (VPNs) to connect to the remote network over a public network such as the internet.

Encoding and Modulatind

Data stored in a computer in the form of 0s and 1s.  To be carried from one place to another (inside or outside the computer), data are usually converted to digital signals.  This is called digital signal conversion or encoding digital data into a digital signal.

Digital to Digital Conversion-   Digital to Digital encoding or conversion is representation of digital information by the digital signal.  For Example, when you transmit data from your computer to your printer, both the original data and he transmitted data are  digital.  In this type of encoding, the binary ‘1s’ and ‘0s’ generated by a computer are translated in to a sequence are voltage pulses that can be propagated over a wire.

            Of the many mechanism for Digital to Digital encoding, we will discuss only those most useful for data communication.  These fall in to three broad categories Unipolar, Polar and By Polar.

Unipolar-  Digital transmission system work by sending voltage pulses along a medium link usually a wire or cable in most type of encoding one voltage level stands for binary ‘0’ and another level stands for binary ‘1’.  The polarity of a pulses refers to whether it is positive of negative.  Unipolar encoding is so named because it uses only one polarity.  This polarity is assigned to one of the two binary states, usually the 1.  The other state, usually the ‘0’ is represented by ‘0’ voltage.

DC Component-  The average amplitude of a Unipolar encoded signal is nonzero.  This creates what is called a direct current (DC) component (A component with zero frequency) when signal contains a DC component.  It cannot travel through media that cannot handle DC components.

Polar-   Polar encoding uses who voltage levels, one positive and one negative by using both levels, in most popular encoding methods the average voltage level on the line is reduced and the DC component problem of unipolar encoding is alleviated.

Polar encoding uses two levels (Positive and negative) of amplitude.

Non Return to Zero-  The NRZ encoding the level of the signal is always either of positive or negative.  The two most popular methods of NRZ transmission are discussed blow.

NRZ-L-  An NRZ-L encoding the level of the signal depend on than type of bit it represents.  A positive voltage usually mean s the bit is a “0”.  And a negative voltage means the bi is a 1 (or vice versa); thus the level of the signal is dependent upon the state of the bit.

In NRZ-L the level of the signal is dependent upon the state of the bit.

NRZ-I-  In NRZ-I an inversion of the voltage level represents a 1 bits,  It is the transition between a positive and negative voltage not the voltage themselves that represent a 1 bit is encountered.  The existence of 1s in the data stream allows the receivers to resynchronize its timer to actual arrival of the transmission.  A string of ‘0s’ can still cause problems.  But because ‘0s’ are not as likely, they are less of a problem.

In NRZ-I the signal is inverted if a 1 is encountered.

Bipolar-   The ‘1s’ are represented by alternating positive and negative voltages.  If  the first ‘1’ bit is represented by the negative amplitude, the third by the positive amplitude and so on.

In bipolar encoding we use three levels positive zero and negative.          

Bit Rate and Baud Rate-  Two terms use frequently to data communication are bit rate and baud rate. “Bits rate is number of bits transmitted during one second.

Baud rate is refer to the number of signal units per second Baud rate is less than or equal to the bit rate.

Example-  An analog signal carries four bits in each signal element.  If 1000 signal elements are sent per second find the baud rate and the bi rate.

  Baud Rate= Number of signal element x 1000 bits per seconds

  Bit Rate=      Baud Rate X Number of bits per signal element

                         1000          X 4 =4bps

Example-  The bit rate of a signal is 3000.  If each signal element carries 6 bits what is the baud rate.

Baud Rate=Bit Rate X Number of bits per signal element

                     3000      X  6 =500 Baud per secound       

Frame Relay

Frame Relay is a virtual – circuit technology that provide low level (Physical and data link layer) service in response to the following demands.

Higher Data Rate at lower Cost-  In the post many organizations used a Wan Technology such as leased line or x.25 to connect single computer.  That data rate was relatively low.  Today, most organization use high speed LAN and want to use WAN to connect this LANs.  One solution to use “T-Line”, but these line provide only point to point connections, no many too many.  Creating a Mash Network out of T-Lines is a very expensive.  For Example – To connect 6 LANS, we need 15 T-Lines.  On the other hand, we need only six-T-Lines to connect the same six LANs to a frame Relay Network.  Frame Relay provides the same type of service at lower cost.

               

            Although the Frame Relay originally was designed o provide a 1.544-Mbps data rate (equivalent to a T-1 Line) today most implementations can handle up to 44.376 Mbps(equivalent to a T-3 Line).

Virtual Circuits-  Frame Relay operates using virtual circuits as opposed to the actual circuits that leased Lines used.  These virtual circuits are what link together the thousand of devices connected o he providers “Cloud” There are two type of virtual circuits permanent and switched.

            Permanent virtual circuits (PVCs) are by far the most common type in use today.  What “permanent” means here is the Telco creates the mapping inside their gear and as long as you pay the bill, they will remain in place.

            Switched virtual circuits (SVCs) are more like a phone call.  The virtual circuit is established when data needs o be tansmitted, then  it’s taken down when the data transfer is complete.

Unguided Media

Unguided media transport  electromagnetic  waves without using a physical conductor this type of communication is often referred to as wireless communication.  Signals are normally broadcast through free space and thus are available to anyone who has a device capable of receiving them. Unguided signals can travel from the source to destination in several ways: ground propagation, sky propagation, and line-of-sight propagation.

In ground propagation, radio waves travel through the lowest portion of the atmosphere, hugging the earth.  These low-frequency signals emanate in all directions from the transmitting antenna and follow the curvature of the planet. Distance depends on the amount of power in the signal: The greater the distance.

In sky propagation higher- frequency radio waves radiate upward into the ionosphere (the layer of atmosphere where particle exist as ions) where they are reflected back to earth.  This type of transmission allows for greater distances with lower output power.

In line-or-sight propagation, very high-frequency signals are transmitted in straight lines directly from antenna to antenna. Antennas must be directional, facing each other, and either tall enough or close enough together not to be affected by the curvature of the earth, line-of-sight propagation is tricky because radio transmissions cannot be completely focused.

SIGNAL

Analog data-   Analog data is human voice.  When somebody speaks, a continuous wave is created   in the air.  This can be captured by a microphone and converted to the analog signal.

Digital data-   Digital data is data stored in memory of the computer in the form of 0s to 1s.  It is usually converted to a digital signal.  When it is transferred from one position to another position.

Analog and digital Signal-   Signal can be analog and digital.  Analog signal can have any value in range.  Digital signals can have only a limited number of value.

                              

Periodic Signals-   A periodic signal consists of a continuously repued pattern.  The period of signal (T) is expressed in seconds.

                                      

                                                  Example of Periodic and aperiodic signal

Aperiodic Signals-   An aperodic or nonperiodic signal has no repetitive pattern.

Amplitude-   Amplitude refer to height of signal.  The unit for amplitude depend on the type of the signal.  For electrical signal, the unit is normally volts ampere or watts.

Sound level	Type of Sound
40db	normal speech
90db	lawn mowers
110db	shotgun blast
120db	jet engine taking off
120db+	rock concerts

Frequency-  The frequency of a periodic function is the number of complete cycles that can o cccur per second,  Frequency is denoted with a lower-case f.  It is defined in terms of the period, as follows:

Period of frequency-   Period refers to the amount of time in seconds, a signal needs to complete one cycle.  Frequency refer to the number of period in  one second.

Unit of Period-   Period is expressed in seconds the communication industry uses five unit to measure period second (s) millisecond, microsecond, nanosecond and picoseconds.

Unit of Frequency-   Frequency is hertz, after the German Physicist Heinrich Rudolf Hertz.  The communications industry uses five units to measure frequency. Hertz, Kilohertz, Megaherth, Gigahertz and Terahertz.

Unit of Frequency-  

Frequency	1 mHz (10−3)	1 Hz (100)	1 kHz (103)	1 MHz (106)	1 GHz (109)	1 THz (1012)
Period (time)	1 ks (103)	1 s (100)	1 ms (10−3)	1 µs (10−6)	1 ns (10−9)	1 ps (10−12)

Digital Signal-   In addition to being represented by an analog signal, data can also be represented by a digital signal.

             For example, A “1” can be encoded as a positive voltage and a “0” as a zero voltage.

Bit Interval and Bit Rate-   Bit interval and bit rate are used to describe digital signals.

        The bit interval is the time required to send one single bit.

        The bit rate is the number of bit interval per second.  This means that the bit rae is the number of bits sent in one second usually expressed in bits per second (bps).  

           

Example of bit rate and bit interval

Problems of using Voice Channels for Digital Transmission
A digital signal is comprised of a number of signals. Specifically, the signal is represented as follows,

signal = f + f3 + f5 +f7 +f9 +f11 +f13 ....f(infinity)

This means a digital signal has a base frequency, plus another at three times the base frequency, plus another at five times the base frequency etc. f3 is called the third harmonic, f5 the fifth harmonic and so on. The third harmonic is one third of the amplitude of the base frequency (called the fundamental frequency), the fifth harmonic is one fifth the amplitude of the fundamental and so on.

In order to send a digital signal across a voice channel, the bandwidth of the channel must allow the fundamental plus third and fifth harmonic to pass without affecting them too much. As can be seen, this is what such a signal looks like, and is the minimum required to be correctly detected as a digital signal by the receiver.

Lets consider sending a 2400bps binary digital signal down a voice channel rated with a bandwidth of 3.1KHz. The base frequency of the digital signal is 1200Hz (it is always half the bit rate), so the fundamental frequency will pass through the channel relatively unaltered. The third harmonic is 3600Hz, which will suffer attenuation and arrive severely altered (if at all). The fifth harmonic has no chance of passing the channel.

In this case it can be seen that only the base frequency will arrive at the end of the channel. This means the receiver will not be able to reconstruct the digital signal properly, as it will require f3 and f5 for proper reconstruction. This results in errors in the detection process by the receiver. Baud Rate-The baud rate indicates the number of bits per second That are transmitted. For example: 300 baud means hat 300 bits are trans mitted each second (abbreviated 300bps).  Assuming asynchronous communication, which requires 10 bits per character, this translates to 30 characters per second (cps).  For slow rates (below 1200 baus), you can divide the baudby 10 o see how many characters per second are sent.

Type of Cable

10BASE2

The 10Base2 Ethernet standard uses thin coaxial (RG-58) cable.  10Base2 has a maximum length of 185 Meters (607feet) and because of its composition offers a fair amount of resistance to interference.  One of the more important is that it is limited to transfer speed of 10 Mbps.  This speed limitation reduces its effectiveness in many network environments.

10BASE5

The 10BASE5 standard uses the thick coaxial (RG-62) cable.  It is a transfer speed of 10Mbps and runs distance of 500 meter.  The 10BASE5 standard specifies a true bus topology, meaning that computer attached to the network cable itself using special cable and connectors it does no use additional networking equipment.

            10BASE5 network must be connected with a minimum distance of 2.5 meters between each other to prevent noise on the cable.

10BASE T

That a normal Ethernet network is one that operates at 10 Mbps and has  the name 10Base T.  Now-a-days more and more origination s are looking for even faster ways to connect there 3, 4 and 5 UTP cable and is limited to distance of hundred meters.

Fast Ethernet 100BASE T

100baseT is a 100 mbps networking standard based on  the principle of standard Ethernet.  A number of standard fall under the fast Ethernet banner; the most commonly implemented is 100BaseTX which use category 5(or higher)  UTP cabling.  The following sections describe he fast Ethernet standards.

10BASE FX

This is the standard of the running fast Ethernet over fiber optic cable.  Due to the cast of implementations this is the rarely used.  One of the largest advantages is its distance capabilities.  100BaseFX can reach an impressive10, 000 meters.

100BASE T4

100BASET4 can use category 3 4and 5 cable to reach speed of 100mbps with regards to distance limitation and other characteristics 100BASE T4  is comparable 100BASE TX.

100BASE TX

This is the fast Ethernet standard of choice on day network. 100BASETX is most often implemented with UTP cable, but it has been known to be used with STP.  100BASE TX operated at speed of 100 mbps and offers a maximum transmission

distance of 100 meters.  The difference between TX and T4 uses all four pairs of wire within the UTP cable TX only use two paired.

  

CSMA/CD

When a device on a network want  to transmit to another device.  The first device  to check to see if the line is clear and then transmit.  The only problem is that two devices perform this action at the same time.  They will both line is clear and so will both attempt to transmit.

Ethernet can accept only one signal at a time.  So the two transmission with collide with each other.  These collisions damage the data packet on the network.  To avoid another collision each system will wait a period of time, known as the back off, before retransmitting the data.  If  data collide again the delay before retransmitting in increase and data is sent again.

The more device that are connected o an Ethernet network the more likely it is there will be collisions on the network this decrease in  performance has driven  improvements in the structures of Ethernet network, improvement include substation of older hubs with new high performance, Ethernet switches.

Ethernet Addressing

Ethernet Addressing-  Ethernet are the physical addressing of the device.  Every LAN card is identify as the Unicast  Ethernet  Address.  The LAN address are as per the IEEE standard.   The IEEE  802.3 standard the assigning the LAN Card.

IEEE assigning  OUI (Organization Uniquely Identification).

Ethernet Frame-   Ethernet frame are used by the data link layer to transfer the packet of the frame the data frame to network layer.  These are mode at the data link layer frame perform data security check and ensure the data is no corrupt.

Ethernet

ETHERNET

Ethernet is a physical and data link layer technology for local Area Network Ethernet was invented by Engineer Robert Metcalfe.

When first widely developed in the 1980’s Ethernet supported a maximum data rate to 100 mbps.  Today Gigabit technology further extends peak performance up to 1000 mbps.

OSI MODEL

OSI is the layer model for the network system designed by ISO .  OSI enable device to network to communicate with each other.

Application Layer-   The Application Layer is the top most layer of the OSI  model.  It provides network access to application and to users.  The application layer to provide service with which users can access all type of network  so application and user use these service to communicate with device and remote application.

Service- 

FTAM(File Transfer and Management)-  Using the application user can access file in a remote host it also enable the user manage file from remote host .

Mail Deliver Box-  Using the application email can be forwarded to another computer “Massage Handling Service” is the OSI protocol use for transfer mail over the internet.

Directory Service- Directory service is a source of information.    A about  such as people organization and file.

Network Virtual Terminal-   It is a software version  a physical terminal version Terminal using user can log on  the computer.  It is remotely connected on the network.

Protocol use in Application Layer- 

TCP-   A connection oriented protocol that is defined at the transport layer of the OSI reference model provide reliable delivery of data.

FTP-  The TCP/IP protocol used for transmitting files between network nodes .  It supports a brand range of file types and is defined in RFC959.

DHCP-   DHCP is used automatically configured a host during boot up on a TCP/IP network and also to change setting while the host is attached.

            This means that you can stored all the available IP address in a central data base along with information such as the subnet mask Gateways DNS server etc.

SMTP-   A protocol used on the internet to provide electronic mail Service.

DNS-   DNS is used to convert user friendly names to IP address.  They are two Zones in DNS.

 Device-  No Device use.

Presentation  Layer-  The Presentation Layer is sixth form the layer top the main function of this layer is the presentation of data.  There are situations when data sent from one system to another system has to be viewed in a different way.  Translation is the main function of the presentation layer the other function is rarely used.

Translation-     In a network there can be many type of computers, for example presentation layer is a mixed systems, we have two different type of systems, in the same network.  One is the MAC Machine and other is the UNIX machine.  Character set in both machine is different, but the presentation layer hide the different.

Compression-  This is an optional function, but it can be done by the presentation layer to improve performance.

Encryption-  We can use Presentation Layer encryption function to ensure security SSL is the one of the popular encryptions used in the Presentation layer.

Protocol-  RIP, SNMP AND DNS

Device-  Gateway

Session Layer-   It control the communication between the hosts the session layer is responsible to establish on connection to the user.

Service-

 Dialog Controller

Synchronization

Closing the Session

Dialog Box-   It allow to device to enter into dialog controller these dialog can take place in there in half duplex and full duplex.

Synchronization-  If the device  is sending he file 100 pages to ensure that these 100 pages without error they are greed link a sending data.

Closing the Session-  Ensure that the data transfer is completed before the session closed.

Protocol-  DNS, NETBIOS, SNTP, SMTP, FTP

Transport Layer-   Transport layer is responsible for source and the destination delivery the entire massage he transport layer ensure that the entire massage he arrived the destination at the computer.

Service- 

Segmentation and Reassembling

Connection Control

Error Control

Segmentation and Reassembling-  A Massage is delivered in to segment with each segment having a sequence number when they arrived that the destination with a sequence number. The transport layer Reassemble the massage.

Connection Control-  There are two type of connection control.

 Connection Oriented

 Connection Less

Error Control-  Two type of Error Control.

Error Deduction

Error Correction

Protocol-   TCP & UDP

Device-   Gateway

Network Layer-  This is responsible for routing and logical addressing.  A Network layer is provide service such as assigning IP address for the delivering the packet.

Routing-  Routing is the selecting the best path for the packet.

 Service-

 Logical Addressing

Routing

Source of destination delivery

Logical Addressing-   The data link layer provide physical addressing which is useful of local Network When the packet is forward a device out of a network be required other addressing scheme o identify source and destination when we use 32 bit logical address.

Routing-   Routing is the process of where in a proper path define for the packet to reach destination routing.

There are two type of routing.

Static Routing

Dynamic Routing

Static Routing-   In a static routing he root o be forwarded by a packet its already sets by the network administration.

Dynamic Routing-   The route to be forwarded by a packet is decided at time of transmission of the packet.

Protocol- 

 IP

ARP

RARP

ICMP

Device-   Router

Source & Destination delivery-   Transfer from the source to its destination delivery.

Data Link Layer-  It handle data transfer between network layer and physical layer data unique data link layer its called as frame.

Service- 

Framing

Physical Addressing

Error Control

Exists Control

Flow Control

Protocol- 

HDLC

SDLC

Device- 

Bridge

Switch

Physical Layer-  It is responsible to transmit up bit over the physical medium.  A bi is a short of a binary digit, and is the smallest unit of information on the computer.  The bit can be either 0 to 1. 

Service- 

Encoding

Transmission Rate

Transmission Mode

Note-  No protocol working in Physical Layer.

Device-   Router and Hub

Data Link Layer For Ethernet-   Ethernet is data link layer responsible for physical source and destination addressing.   The packet in to frame for transmitting the network  layer.