Introduction to Computer Engineering

WEEK-11/12Computer Networks

Assoc. Prof. Dr. Ahmet Turan ÖZCERİT

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Network Classification

Band-width

OSI reference model

Network Devices

Cable standards

Network Topologies

TCP/IP Model and Address Classes

COMPUTER NETWORKSYou will learn:

FundamentalsHe/she can define network parameters and devices

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What is a Computer Network?A computer network is a system in which multiple computers are connected to each other to share information and resources.

Computer Networks ClassificationHe/she can define network parameters and devices

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Local Area NetworksHigh speedBuilding, Room, DepartmentIntranet Shared printers, storageUTP cables (copper) or Wifi

Campus NetworksSimilar to LANsSeveral LANsSeveral BuildingsBackbone fiber optics

Computer Networks ClassificationHe/she can define network parameters and devices

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Wide Area NetworksCountry-wide or globalMany servers Fiber optic and copper cables (incl. sub-

marine)Satalite tranmission

Remote ConnectionFew distant terminals for servers ADSL, GSM connection

Bandwidth and Transmission SpeedHe/she can define network parameters and devices

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Bandwidth is the trasmitted or received data rate in one second (bps: bit per second )

LAN : 100Mbs-10Gbs

WAN: 1Mbs-1Gbs

OSI Reference ModelHe/she can define network parameters and devices

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OSI Reference ModelHe/she can define network parameters and devices

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Physical (Layer 1)OSI Model, Layer 1 conveys the bit stream - electrical impulse, light or radio signal — through the network at the electrical and mechanical level. It provides the hardware means of sending and receiving data on a carrier, including defining cables, cards and physical aspects. Fast Ethernet, RS232, and ATM are protocols with physical layer components.Layer 1 Physical examples include Ethernet, FDDI, B8ZS, V.35, V.24, RJ45.

Data Link (Layer 2)At OSI Model, Layer 2, data packets are encoded and decoded into bits. It furnishes transmission protocol knowledge and management and handles errors in the physical layer, flow control and frame synchronization. The data link layer is divided into two sub layers: The Media Access Control (MAC) layer and the Logical Link Control (LLC) layer. The MAC sub layer controls how a computer on the network gains access to the data and permission to transmit it. The LLC layer controls frame synchronization, flow control and error checking.Layer 2 Data Link examples include PPP, FDDI, ATM, IEEE 802.5/ 802.2, IEEE 802.3/802.2, HDLC, Frame Relay.

OSI Reference ModelHe/she can define network parameters and devices

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Network (Layer 3)Layer 3 provides switching and routing technologies, creating logical paths, known as virtual circuits, for transmitting data from node to node. Routing and forwarding are functions of this layer, as well as addressing, internetworking, error handling, congestion control and packet sequencing.Layer 3 Network examples include AppleTalk DDP, IP, IPX.

Transport (Layer 4)OSI Model, Layer 4, provides transparent transfer of data between end systems, or hosts, and is responsible for end-to-end error recovery and flow control. It ensures complete data transfer.Layer 4 Transport examples include SPX, TCP, UDP.

OSI Reference ModelHe/she can define network parameters and devices

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This layer establishes, manages and terminates connections between applications. The session layer sets up, coordinates, and terminates conversations, exchanges, and dialogues between the applications at each end. It deals with session and connection coordination.Layer 5 Session examples include NFS, NetBios names, RPC, SQL.

Presentation (Layer 6)This layer provides independence from differences in data representation (e.g., encryption) by translating from application to network format, and vice versa. The presentation layer works to transform data into the form that the application layer can accept. This layer formats and encrypts data to be sent across a network, providing freedom from compatibility problems. It is sometimes called the syntax layer.     Layer 6 Presentation examples include encryption, ASCII, EBCDIC, TIFF, GIF, PICT, JPEG, MPEG, MIDI.

OSI Reference ModelHe/she can define network parameters and devices

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Application (Layer 7)OSI Model, Layer 7, supports application and end-user processes. Communication partners are identified, quality of service is identified, user authentication and privacy are considered, and any constraints on data syntax are identified. Everything at this layer is application-specific. This layer provides application services for file transfers, e-mail, and other network software services. Telnet and FTP are applications that exist entirely in the application level. Tiered application architectures are part of this layer.     Layer 7 Application examples include WWW browsers, NFS, SNMP, Telnet, HTTP, FTP

Network DevicesHe/she can define network parameters and devices

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Network DevicesHe/she can define network parameters and devices

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Gateway: this device is placed at a network node and interfaces with another network that uses different protocols. It works on OSI layers 4 to 7.

•Router: a specialized network device that determines the next network point to which it can forward a data packet towards the ultimate destination of the packet. Unlike a gateway, it cannot interface different protocols. It works on OSI layer 3.

•Switch: a device that allocates traffic from one network segment to certain lines (intended destination(s)) which connect the segment to another network segment. Unlike a hub, a switch splits the network traffic and sends it to different destinations rather than to all systems on the network. It works on OSI layer 2.Other hardware devices used for establishing networks or dial-up connections include:

Network DevicesHe/she can define network parameters and devices

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•Bridge: a device that connects multiple network segments along the data link layer. It works on OSI layer 2.

•Hub: a device that connects multiple Ethernet segments, making them act as a single segment. When using a hub, every attached device shares the same broadcast domain and the same collision domain. Therefore, only one computer connected to the hub is able to transmit at a time. Depending on the network topology, the hub provides a basic level 1 OSI model connection among the network objects (workstations, servers, etc.). It provides bandwidth which is shared among all the objects, in contrast to switches, which provide a connection between individual nodes. It works on OSI layer 1.

•Repeater: a device which amplifies or regenerates digital signals received while sending them from one part of a network into another. It works on OSI layer 1.

Network DevicesHe/she can define network parameters and devices

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Hybrid network devices include:•Multilayer switch: a switch which, in addition to switching on OSI layer 2, provides functionality at higher protocol layers.

•Protocol converter: a hardware device that converts between two different types of transmission, such as asynchronous and synchronous transmissions.

•Bridge router (brouter): a device that combines router and bridge functionality and therefore works on OSI layers 2 and 3.

Hardware or software components which typically sit on the connection point of different networks (for example, between an internal network and an external network) include:•Proxy server: computer network service which allows clients to make indirect network connections to other network services.•Firewall: a piece of hardware or software put on the network to prevent some communications forbidden by the network policy.•Network address translator (NAT): network service (provided as hardware or as software) that converts internal to external network addresses and vice versa.

Network DevicesHe/she can define network parameters and devices

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•Multiplexer: a device that combines several electrical signals into a single signal.

•Network interface controller (NIC): a device connecting a computer to a wire-based computer network.

•Wireless network interface controller: a device connecting the attached computer to a radio-based computer network.

•Modem: device that modulates an analog "carrier" signal (such as sound) to encode digital information, and that also demodulates such a carrier signal to decode the transmitted information. Used (for example) when a computer communicates with another computer over a telephone network.•ISDN terminal adapter (TA): a specialized gateway for ISDN.•Line driver: a device to increase transmission distance by amplifying the signal; used in base-band networks only.

Cables and WirelessHe/she can define network parameters and devices

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Twisted pairTwisted pair cabling is a form of wiring in which pairs of wires (the forward and return conductors of a single circuit) are twisted together for the purposes of canceling out electromagnetic interference (EMI) from other wire pairs and from external sources. This type of cable is used for home and corporate Ethernet networks.There are two major types of twisted pair cables:

shielded, unshielded.

Ethernet crossover cableAn Ethernet crossover cable is a type of twisted pair Ethernet cable used to connect computing devices together directly that would normally be connected via a network switch, hub or router, such as directly connecting two personal computers via their network adapters. Most current Ethernet devices support Auto MDI-X, so it doesn't matter whether you use crossover or straight cables.

Cables and WirelessHe/she can define network parameters and devices

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Fiber optic cableAn optical fiber cable consists of a center glass core surrounded by several layers of protective material. The outer insulating jacket is made of Teflon or PVC to prevent interference. Optical fiber deployment is more expensive than copper but offers higher bandwidth and can cover longer distances.There are two major types of optical fiber cables: short-range multi-mode fiber and long-range single-mode fiber.

Coaxial cableCoaxial lines confine the electromagnetic wave inside the cable, between the center conductor and the shield. The transmission of energy in the line occurs totally through the dielectric inside the cable between the conductors. Coaxial lines can therefore be bent and twisted (subject to limits) without negative effects, and they can be strapped to conductive supports without inducing unwanted currents in them.The most common use for coaxial cables is for television and other signals with a bandwidth of several hundred megahertz to gigahertz. Although in most homes coaxial cables have been installed for transmission of TV signals, new technologies (such as the ITU-T G.hn standard) open the possibility of using home coaxial cable for high-speed home networking applications (Ethernet over coax).In the 20th century they carried long distance telephone connections.

Cables and WirelessHe/she can define network parameters and devices

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Patch cableA patch cable is an electrical or optical cable used to connect one electronic or optical device to another for signal routing. Devices of different types (e.g. a switch connected to a computer, or a switch connected to a router) are connected with patch cords. Patch cords are usually produced in many different colors so as to be easily distinguishable,[2] and are relatively short, perhaps no longer than two meters. In contrast to on-premises wiring, patch cables are more flexible but may also be less durable.

Power linesAlthough power wires are not designed for networking applications, new technologies like Power line communication allows these wires to also be used to interconnect home computers, peripherals or other networked consumer products. On December 2008, the ITU-T adopted Recommendation G.hn/G.9960 as the first worldwide standard for high-speed powerline communications.[3] G.hn also specifies communications over phonelines and coaxial

Cables and WirelessHe/she can define network parameters and devices

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Cables and WirelessHe/she can define network parameters and devices

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Wireless NetworksHe/she can define network parameters and devices

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Types of Wireless Networks

1-WLANS: Wireless Local Area NetworksWLANS allow users in a local area, such as a university campus or library, to form a network or gain access to the internet. A temporary network can be formed by a small number of users without the need of an access point; given that they do not need access to network resources.

2- WPANS: Wireless Personal Area NetworksThe two current technologies for wireless personal area networks are Infra Red (IR) and Bluetooth (IEEE 802.15). These will allow the connectivity of personal devices within an area of about 30 feet. However, IR requires a direct line of site and the range is less.

Wireless NetworksHe/she can define network parameters and devices

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Types of Wireless Networks

3-WMANS: Wireless Metropolitan Area NetworksThis technology allows the connection of multiple networks in a metropolitan area such as different buildings in a city, which can be an alternative or backup to laying copper or fiber cabling.

4-WWANS: Wireless Wide Area NetworksThese types of networks can be maintained over large areas, such as cities or countries, via multiple satellite systems or antenna sites looked after by an ISP. These types of systems are referred to as 2G (2nd Generation) systems.

Wireless NetworksHe/she can define network parameters and devices

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Type Coverage Performance Standards Applications

Wireless PAN Within reach of a person Moderate

Wireless PAN Within reach of a person Moderate Bluetooth, IEEE 802.15, and IrDa Cable replacement for peripherals

Cable replacement for peripherals

Wireless LAN Within a building or campus High IEEE 802.11, Wi-Fi, and

HiperLANMobile extension of wired networks

Wireless MAN Within a city High Proprietary, IEEE 802.16,

and WIMAXFixed wireless between homes and businesses and the Internet

Wireless WAN Worldwide Low CDPD and Cellular 2G, 2.5G,

and 3GMobile access to the Internet from outdoor areas

Comparison of Wireless Network Types

Network TopologiesHe/she can define network parameters and devices

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BUS TopologyBus topology is a network type in where every computer and network device is connected to single cable.

Network TopologiesHe/she can define network parameters and devices

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Features of Bus Topology1.It transmits data only in one direction.2.Every device is connected to a single cableAdvantages of Bus Topology3.It is cost effective.4.Cable required is least compared to other network topology.5.Used in small networks.6.It is easy to understand.7.Easy to expand joining two cables together.Disadvantages of Bus Topology8.Cables fails then whole network fails.9.If network traffic is heavy or nodes are more the performance of the network decreases.10.Cable has a limited length.11.It is slower than the ring topology.

Network TopologiesHe/she can define network parameters and devices

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RING TopologyIt is called ring topology because it forms a ring as each computer is connected to another computer, with the last one connected to the first. Exactly two neighbors for each device.

Network TopologiesHe/she can define network parameters and devices

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Features of Ring Topology1.A number of repeaters are used and the transmission is unidirectional.2.Date is transferred in a sequential manner that is bit by bit.

Advantages of Ring Topology3.Transmitting network is not affected by high traffic or by adding more nodes, as only the nodes having tokens can transmit data.4.Cheap to install and expand

Disadvantages of Ring Topology5.Troubleshooting is difficult in ring topology.6.Adding or deleting the computers disturbs the network activity.7.Failure of one computer disturbs the whole network.

Network TopologiesHe/she can define network parameters and devices

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STAR TopologyIn this type of topology all the computers are connected to a single hub through a cable. This hub is the central node and all others nodes are connected to the central node.

Network TopologiesHe/she can define network parameters and devices

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Features of Star Topology1.Every node has its own dedicated connection to the hub.2.Acts as a repeater for data flow.3.Can be used with twisted pair, Optical Fibre or coaxial cable.

Advantages of Star Topology4.Fast performance with few nodes and low network traffic.5.Hub can be upgraded easily.6.Easy to troubleshoot.7.Easy to setup and modify.8.Only that node is affected which has failed rest of the nodes can work smoothly.

Disadvantages of Star Topology9.Cost of installation is high.10.Expensive to use.11.If the hub is affected then the whole network is stopped because all the nodes depend on the hub.12.Performance is based on the hub that is it depends on its capacity

Network TopologiesHe/she can define network parameters and devices

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MESH TopologyIt is a point-to-point connection to other nodes or devices. Traffic is carried only between two devices or nodes to which it is connected. Mesh has n (n-2)/2 physical channels to link hn devices.

Network TopologiesHe/she can define network parameters and devices

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Types of Mesh Topology1.Partial Mesh Topology : In this topology some of the systems are connected in the same fashion as mesh topology but some devices are only connected to two or three devices.2.Full Mesh Topology : Each and every nodes or devices are connected to each other.Features of Mesh Topology3.Fully connected.4.Robust.5.Not flexible.Advantages of Mesh Topology6.Each connection can carry its own data load.7.It is robust.8.Fault is diagnosed easily.9.Provides security and privacy.Disadvantages of Mesh Topology10.Installation and configuration is difficult.11.Cabling cost is more.12.Bulk wiring is required.

Network TopologiesHe/she can define network parameters and devices

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TREE TopologyIt has a root node and all other nodes are connected to it forming a hierarchy. It is also called hierarchical topology. It should at least have three levels to the hierarchy.

Network TopologiesHe/she can define network parameters and devices

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Features of Tree Topology1.Ideal if workstations are located in groups.2.Used in Wide Area Network.

Advantages of Tree Topology3.Extension of bus and star topologies.4.Expansion of nodes is possible and easy.5.Easily managed and maintained.6.Error detection is easily done.

Disadvantages of Tree Topology7.Heavily cabled.8.Costly.9.If more nodes are added maintenance is difficult.10.Central hub fails, network fails.

Network TopologiesHe/she can define network parameters and devices

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HYBRID TopologyIt is two different types of topologies which is a mixture of two or more topologies. For example if in an office in one department ring topology is used and in another star topology is used, connecting these topologies will result in Hybrid Topology (ring topology and star topology).

Network TopologiesHe/she can define network parameters and devices

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Features of Hybrid Topology1.It is a combination of two or topologies2.Inherits the advantages and disadvantages of the topologies included

Advantages of Hybrid Topology3.Reliable as Error detecting and trouble shooting is easy.4.Effective.5.Scalable as size can be increased easily.6.Flexible.

Disadvantages of Hybrid Topology7.Complex in design.8.Costly.

TCP/IP ModelHe/she can define network parameters and devices

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TCP/IP means transmission control protocol and internet protocol. Protocols are set of rules which govern every possible communication over the internet. These protocols describe the movement of data between the host computers or internet. These offer simple naming and addressing schemes.

TCP/IP that is transmission control protocol and the internet protocol was developed by Department of Defence’s Project Research Agency (ARPA, later DARPA) under the project of network interconnection.

Originally it was created to connect military networks together, later it was used by government agencies and universities. It is robust to failures and flexible to diverse networks. Most widely used protocol for interconnecting computers and it is the protocol of the internet.

TCP/IP ModelHe/she can define network parameters and devices

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Layer 1: Host-to-network Layer1.Lowest layer of the all.2.Protocol is used to connect the host, so that the packets can be sent over it.3.Varies host to host and network to network.

Layer 2: Internet layer4.Selection of a packet switching network which is based on a connectionless internetwork layer is called a internet layer.5.It the layer which holds the whole architecture together.6.It allows the host to insert the packets.7.It helps the packet to travel independently to the destination.8.Order in which packets are received is different from the way they are sent.9.IP (internet protocol) is used in this layer.

TCP/IP ModelHe/she can define network parameters and devices

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Layer 3: Transport Layer1.It decides if data transmission should be on parallel path or single path.2.Functions such as multiplexing, segmenting or splitting on the data done by layer four that is transport layer.3.Transport layer breaks the message (data) into small units so that they are handled more efficiently by the network layer.4.Functions of the transport layer are same as the OSI model.5.Transport layer also arrange the packets sent in sequence.

Layer 4: Application Layer6.Protocols used in this layer are high level protocols such as TELNET, FTP (file transfer protocol etc.

TCP/IP ModelHe/she can define network parameters and devices

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Pros of TCP/IP It operated independently.It is scalable.Client/server architecture.Supports a number of routing protocols.Can be used to establish a connection between two computers.

Cons of TCP/IPIn this, the transport layer does not guarantee delivery of packets.The model cannot be used in any other application.Replacing protocol is not easy.It has not clearly separated its services, interfaces and protocols.

TCP/IP ProtocolsHe/she can define network parameters and devices

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TCP/IP ProtocolsHe/she can define network parameters and devices

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Network Interface Layer

The Network Interface layer (also called the Network Access layer) sends TCP/IP packets on the network medium and receives TCP/IP packets off the network medium. TCP/IP was designed to be independent of the network access method, frame format, and medium. Therefore, you can use TCP/IP to communicate across differing network types that use LAN technologies—such as Ethernet, Token Ring and 802.11 wireless LAN—and WAN technologies—such as Frame Relay and Asynchronous Transfer Mode (ATM). By being independent of any specific network technology, TCP/IP can be adapted to new technologies.

TCP/IP ProtocolsHe/she can define network parameters and devices

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Internet LayerThe Internet layer responsibilities include addressing, packaging, and routing functions. The Internet layer is analogous to the Network layer of the OSI model.

•The Address Resolution Protocol (ARP) resolves the Internet layer address to a Network Interface layer address such as a hardware address.

•The Internet Protocol (IP) is a routable protocol that addresses, routes, fragments, and reassembles packets.

•The Internet Control Message Protocol (ICMP) reports errors and other information to help you diagnose unsuccessful packet delivery.

•The Internet Group Management Protocol (IGMP) manages IP multicast groups.

TCP/IP ProtocolsHe/she can define network parameters and devices

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Transport Layer

The Transport layer (also known as the Host-to-Host Transport layer) provides the Application layer with session and datagram communication services. The Transport layer encompasses the responsibilities of the OSI Transport layer. The core protocols of the Transport layer are TCP and UDP.

TCP provides a one-to-one, connection-oriented, reliable communications service. TCP establishes connections, sequences and acknowledges packets sent, and recovers packets lost during transmission.

In contrast to TCP, UDP provides a one-to-one or one-to-many, connectionless, unreliable communications service. UDP is used when the amount of data to be transferred is small (such as the data that would fit into a single packet), when an application developer does not want the overhead associated with TCP connections, or when the applications or upper-layer protocols provide reliable delivery.

TCP/IP ProtocolsHe/she can define network parameters and devices

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Application LayerThe Application layer allows applications to access the services of the other layers, and it defines the protocols that applications use to exchange data. The Application layer contains many protocols, and more are always being developed.The most widely known Application layer protocols help users exchange information:

•The Hypertext Transfer Protocol (HTTP) transfers files that make up pages on the World Wide Web.•The File Transfer Protocol (FTP) transfers individual files, typically for an interactive user session.•The Simple Mail Transfer Protocol (SMTP) transfers mail messages and attachments.Additionally, the following Application layer protocols help you use and manage TCP/IP networks:•The Domain Name System (DNS) protocol resolves a host name, such as www.microsoft.com, to an IP address and copies name information between DNS servers.•The Routing Information Protocol (RIP) is a protocol that routers use to exchange routing information on an IP network.•The Simple Network Management Protocol (SNMP) collects and exchanges network management information between a network management console and network devices such as routers, bridges, and servers.

TCP HeaderHe/she can define network parameters and devices

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Source Port: 16 bits :The source port number. Destination Port: 16 bits: The destination port number. Sequence Number: 32 bits: The sequence number of the first data octet in this segment (except when SYN is present). If SYN is present the sequence number is the initial sequence number (ISN) and the first data octet is ISN+1. Acknowledgment Number: 32 bits: If the ACK control bit is set this field contains the value of the next sequence number the sender of the segment is expecting to receive. Once a connection is established this is always sent. Data Offset: 4 bits: The number of 32 bit words in the TCP Header. This indicates where the data begins. The TCP header (even one including options) is an integral number of 32 bits long. Reserved: 6 bits: Reserved for future use. Must be zero. Control Bits: 6 bits (from left to right): URG: Urgent Pointer field significant ACK: Acknowledgment field significant PSH: Push Function RST: Reset the connection SYN: Synchronize sequence numbers FIN: No more data from sender Window: 16 bits: The number of data octets beginning with the one indicated in the acknowledgment field which the sender of this segment is willing to accept. Checksum: 16 bits: The checksum field is the 16 bit one's complement of the one's complement sum of all 16 bit words in the header and text.

IP HeaderHe/she can define network parameters and devices

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•Protocol Version(4 bits) : This is the first field in the protocol header. This field occupies 4 bits. This signifies the current IP protocol version being used. Most common version of IP protocol being used is version 4 while version 6 is out in market and fast gaining popularity.•Header Length(4 bits) : This field provides the length of the IP header. The length of the header is represented in 32 bit words. This length also includes IP options (if any). Since this field is of 4 bits so the maximum header length allowed is 60 bytes. Usually when no options are present then the value of this field is 5. Here 5 means five 32 bit words ie 5 *4 = 20 bytes.•Type of service(8 bits) : The first three bits of this field are known as precedence bits and are ignored as of today. The next 4 bits represent type of service and the last bit is left unused. The 4 bits that represent TOS are : minimize delay, maximize throughput, maximize reliability and minimize monetary cost.•Total length(16 bits): This represents the total IP datagram length in bytes. Since the header length (described above) gives the length of header and this field gives total length so the length of data and its starting point can easily be calculated using these two fields. Since this is a 16 bit field and it represents length of IP datagram so the maximum size of IP datagram can be 65535 bytes. When IP fragmentation takes place over the network then value of this field also changes. There are cases when IP datagrams are very small in length but some data links like ethernet pad these small frames to be of a minimum length ie 46 bytes. So to know the exact length of IP header in case of ethernet padding this field comes in handy.•Identification(16 bits): This field is used for uniquely identifying the IP datagrams. This value is incremented every-time an IP datagram is sent from source to the destination. This field comes in handy while reassembly of fragmented IP data grams.•Flags(3 bits): This field comprises of three bits. While the first bit is kept reserved as of now, the next two bits have their own importance. The second bit represents the ‘Don’t Fragment’ bit. When this bit is set then IP datagram is never fragmented, rather its thrown away if a requirement for fragment arises. The third bit represents the ‘More Fragment’ bit. If this bit is set then it represents a fragmented IP datagram that has more fragments after it. In case of last fragment of an IP datagram this bit is not set signifying that this is the last fragment of a particular IP datagram.

IP HeaderHe/she can define network parameters and devices

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•Fragment offset(13 bits): In case of fragmented IP data grams, this field contains the offset( in terms of 8 bytes units) from the start of IP datagram. So again, this field is used in reassembly of fragmented IP datagrams.•Time to live(8 bits) : This value represents number of hops that the IP datagram will go through before being discarded. The value of this field in the beginning is set to be around 32 or 64 (lets say) but at every hop over the network this field is decremented by one. When this field becomes zero, the data gram is discarded. So, we see that this field literally means the effective lifetime for a datagram on network.•Protocol(8 bits) : This field represents the transport layer protocol that handed over data to IP layer. This field comes in handy when the data is demultiplex-ed at the destination as in that case IP would need to know which protocol to hand over the data to.• Header Checksum(16 bits) : This fields represents a value that is calculated using an algorithm covering all the fields in header (assuming this very field to be zero). This value is calculated and stored in header when IP data gram is sent from source to destination and at the destination side this checksum is again calculated and verified against the checksum present in header. If the value is same then the datagram was not corrupted else its assumed that data gram was received corrupted. So this field is used to check the integrity of an IP datagram.•Source and destination IP(32 bits each) : These fields store the source and destination address respectively. Since size of these fields is 32 bits each so an IP address os  maximum length of 32 bits can be used. So we see that this limits the number of IP addresses that can be used. To counter this problem, IP V6 has been introduced which increases this capacity.•Options(Variable length) : This field represents a list of options that are active for a particular IP datagram. •Data

QUESTIONS

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