Task 1aWhat are protocolsProtocolsare sort of like rules, they are used worldwide by companies to allow computerto communicate with each other local and globally. Protocols allow for computerto say what bit of the conversation they are transmitting and receiving andwhen it starts and ends. Protocols are important because they allow fordifferent company’s products to communicate together with eases as they are allusing the same type of Business that controlthe protocolsThere areloads of businesses and companies that control the protocols in the world ofnetworking. Some of the most common ones are:· ISO· ITU-T· ICANN· IEEE IOSISO whichstands for (international organisation for standardisation, is one of theworld’s biggest companies that creating and providing standards they alsoprovide for the OSI (open systems interconnection) this is a 7 layered modelthat was created back in 1984 and was created as the main networking frameworkfor adding protocol in layers this will controls the flow of protocols that arebeing added at one time the layers are split down, with the lower dealing withthe electrical signals, and the binary data. With the more upper layers dealingwith the networks request and response and how data is represented. https://mplsnet.files.
wordpress.com/2014/06/osi-model.gif?w=645accessed on the 06/01/20180ITU-TITU-T standsfor (International Telecommunications Union-Telecommunication) defines elementsin the global infrastructure for ICT. It was first founded in 1865, and hassince been developing standard for the whole globe to follow. It is one of theoldest and biggest standard creating company’s. ICANNICANN standsfor (internet corporation for assigned names and numbers) and they are in chargeof unique address so computers can reach another person through the internet.
ICANN was formed in 1998. And is made up of people who are dedicated to keepingthe internet safe and securedIEEEThe IEEE stands for Institute of electrical and electronicsengineers. The IEEE spans across 160 countries and has around 423,000 members,they are the most trusted when it comes to computing, technology and engineeringaround the whole world. They are split into different groups that focused oncreating new and improved standards: 802.1Higher Layer LAN Group, 802.3 Ethernet Group, 802.
11 Wireless LAN Group,802.15 WirelessPersonal Area Network WPAN Group, 802.16 Broadband Wireless Access Group,802.18 Radio Regulatory TAG, 802.19 Wireless Coexistence Group, 802.21 MediaIndependent Handover Services Group, 802.
22 Wireless Regional Area NetworksGroup, 802.24 Smart Grid TAG. Proprietary protocolsTheseprotocols are mainly developed by one company for their own devices which theymake. So it would not be able to work or communicate with another company’sdevice like a Microsoft device. For an example AppleTalk is a proprietaryprotocol that was developed by the company apple. This protocol was created toonly work on apple devices. Essentially proprietary protocols are privatelyowned protocols which only work on the device chosen by that company, and usersmust pay for the company to uses them.
But it will not allow for users tocommunicate with different company’s devices. But some people can develop theirown proprietary protocols for their devices as a means of better security,allow for only their devices to communicate with each other. Layered model Task 1bLayer 4 protocolsTCP:TCP standsfor transmission control protocol; it is a connection orientated protocol andis able to keep track of the connection between devices. TCP required a directconnection to a host to be established before it is able to transmit data. TCPis part of the transport layer of the OSI layer which is in charge ofencapsulating and de-encapsulating segments of data and also assigns potnumbers to applications.
E.g. HTTP – port number: 80, the protocol also uses amethod called the 3-way hand shake to establish a secure connection between twodevices. Flow controlFlow controlis used by the TPC protocol to manage the amount of data that a device cantransmit at one time to the end device, it does this by using the window sizeheader this allows for the receiving device to tell the transition device howmuch data it process in one go. This allows for a control over the network asnot too much is sent a once. TCP header field Source port:this is a number that source device that is randomly created for theunregistered port range and is used to identify where the transition came from.Destinationport: this is where the data transition need to be sent to and this port numberwill be in the range of the well know port range.Sequence number:this is a number that will be given to a fragment of data that will tell thedestination device when the start of the sequence of data is arriving.
This willalso tell the device when the next segment of data is arriving which will normallybe 1 or more then the last sequence data size. But if data is lost then it willstart at the bit of data that was lost.Acknowledgmentnumber: this is like the opposite to the sequence number as it is the last in thedata fragment to tell the end device that that segment transition has ended Data offset:will tell the device the size of the headerReserved: thisis the area of the header that is set to 0 for any uses in the future.Control flag:flags are used to connect device together and terminate them as well.
Window size:will tell the transition device how the maximum amount of data can be sentbefore another sequence number is neededChecksum:this is used to check if any of the data is corrupt and to integrity check ofany transmissions.Urgent pointer:this is like the window size but it is more for the amount of data an urgent orhigh frequency transition need to be sent.Optional data:this is saved for any extra data that need to be added on at the end.
3-way handshakeIn this processthe first host device will send a synchronisation (SYN) flag to the end deviceit is trying to connect to. To go along with this the first device sends asequence number with the SYN flag to keep an order to communication. When theend device get this SYN flag it will send that flag and the sequence numberback to the first host but it will also add and Acknowledgement (ACK) flag, finallywhen the host device receives all that it will send a final ACK flag to the enddevice to established a full connecting between them. The image below shouldshow this in an easier way. https://hpbn.co/assets/diagrams/eefa1170a673da0140efe1ece7a2884b.svgaccessed on the 06/01/2018similar tothe 3-way handshake here is also another process called the termination processbut this is for ending/terminating a connection between two devices. The onlybig difference between these two process is the device that want to end theconnection send a finish (FIN) flag to the end device.
Then the end devicesends a ACK flag back to the first device then it follows it up with a FINflag. Finally, the first device sends a final ACK flag and this willend/terminate their connection together. https://image.slidesharecdn.com/networktechnologypg4-140221145113-phpapp01/95/osi-transport-layer-12-638.
jpg?cb=1392994310access on the 06/01/2018UDPUDP standsfor User Datagram Protocol this known as the best effort, real time protocol asit has no concern about how your data reaches the end device, in simple term itjust wants to get rid of it as fast as possible and doesn’t care what state itreaches the end location. UDP is a connectionless protocol so it is no veryreliable when it comes to data transition as there is no dedicated end to endconnection. However, UDP is advantageous when it comes to video and voicecalls, videos and online gaming as all of these require fast connectionlessstreaming. As using TCP for these would causes slow bad interaction especialwhen it comes to online gaming. UDP header field http://www.tcpipguide.com/free/diagrams/udpformat.pngaccessed on the 06/01/2018Source port:this is a number that source device that is randomly created for theunregistered port range and is used to identify where the transition came from.
Destinationport: this is where the data transition need to be sent to and this port numberwill be in the range of the well know port range.Length: the lengthheader tells the device how big the packet will beChecksum:this is used to check if any of the data is corrupt and to integrity check ofany transmissions.Data: thisis where that data that will be sent will be put.Layer 3 protocolsthis layeris that is in charge of the IP protocols which are connectionless protocolswhich allow user to transmit and receive data. IP stands for Internet protocol.
IPv4IPv4 wascreated in 1983 and was the first IP protocol to be created and is a 32 bit issize and allow for 4,294,967,296 IP address to be allocated to users. But almostall of these IP have been allocated as more and more people all over the worldare coming online and people owning more than one connected device. IPv4 hasdifferent types of addressing private and public. Private IP addressing can beused for all device on a single LAN as it can use a IP addressing pool for acommunication outside the network as it will assign a random IP address to thisdevice for its IP address pool.
Private IP addresses have been allocated arange to fall into these can be used as many times on different privatenetworks as they are not connected to the internet these are – 192.168.0.
0 to192.168.255.255 172.16.0.
0 to172.16.255.255 10.0.
255.255.Public IPaddressing are globally unique meaning there is only one in the whole world. Theseare assigned to a user through there ISP. Public IP address allow for users tocommunicate and interact through the network. Apart from the private addresslist all other IP addresses are public IP addressingThe IPv4address is made up of 4 octets which all contain 8 bits which add up to a totalof 32 bits.
And can be broke down into two portions which are the networkportion and the host portion, these identify how big the network is and howmany host IPs are available. The network portion is usually assigned by yourISP or the by the subnet mask.Subnet Mask the uses ofa subnet are to show how many host are using a network. This is also like an IPaddress as it is split down into two parts the network portion and the host portionfor example if you had a subnet of 255.255.0 then the network can have 254 hoston it.
and the network portion would be the 255.255.255.
and this will tell youwho’s network your computer(s) is on. The network must take away to allocatedspaces from the host portion to allow for the network address and the broadcastaddress this is why the example is 254host and not 255 host as it need to taketwo off. NATNAT standsfor Network Address Translation and it is used in IPv4 addressing to allow adevice on a local network to keep the same address and IP address it was givenfrom the IP address pool and allow for then to connect to the internet oranother network. IPv6To accommodatefor the growing world and more device need IP address a new IP was createdcalled IPv6 and this was to relive IPv4 as it was running out of address tohand out. This is a better and improved version of IPv4 it allows for over 300 Quintilianaddress this is because it is made up of 8 Hextets and is 64 bit long whichallow for many different version of address to be created. This IP address canalso be split down into three parts the global routing prefix and the subnet IDand the Interface ID. An example of this is 2001:0db8:85a3:0000:0000:8a2e:0370:7334 so to split it down the 2001:0db8:85a3: is the global routing prefixand this is mainly given to you by your ISP to tell you who’s network yourusing. The next bit which is 0000: is called the subnet ID, which is a 16-bitlong subnet ID and this will tell you how many subnets are on your network.
Andit will allow up to 65,636 subnets to be created. Then when the Subnet ID andthe global routing prefixed are put together then they make up the subnetprefix, and final the last bit which will be the 0000:8a2e: 0370:7334 is theinterface ID and basically this bit can be automatically assigned or staticallyassigned. Prefix-lengthThe IPv6prefix-length is similar to Layer 2 protocolsLLC (local linkcontrol)the LLC operatesat the upper parts of the data link layer of the OSI model, and is standardizedas IEEE 802.2. LLC is used mainly for multiplexing feature, and is used to makesure that data transmissions keep their integrity. It also controls thecommunication between the other layers of the OSI model and to pass packet downto the physical layer and through the network.
EthernetT0heEthernet protocol is used in both the data link layer and the physical layer onthe OSI layer, and is able large amounts of data with speeds of 10 MBPS or upto 100MBPS, at a rate of 1500 Bytes per packets. The Ethernet protocol is themost used protocol on a network. The Ethernet protocol is standardized by theIEEE 802.3 standard, the protocol also uses two features of transmission whichare Frames and Packets. Mac sublayerMedia accesscontrol (mac) in the osi layer the mac layer is a communication protocol and isa sublayer for the data link layer. The mac sublayer allows for addressing andchannel access control, this make it possible for several network nodes tocommunicate on multiple access networks that allow foe shared medium.
Mac layeris also responsible for send in packets to and from the NIC (network interface card)to another one across the network http://www.tcpipguide.com/free/t_IPv6GlobalUnicastAddressFormat-2.htmaccess on the 07/01/2018