Internet Internet Protocols.pptx( technology)

Protocols

1. Unit Ist OSI Model and TCP/IP Model Protocols

2. Application Layer protocol:- TELNET: Telnet stands for the  TEL etype   NET work . It helps in terminal emulation. It allows Telnet clients to access the resources of the Telnet server. It is used for managing files on the internet. It is used for the initial setup of devices like switches. The telnet command is a command that uses the Telnet protocol to communicate with a remote device or system. Port number of telnet is 23.  Command   : telnet [\\RemoteServer] \\RemoteServer : Specifies the name of the server to which you want to connect  

3. 2. FTP: FTP stands for file transfer protocol. It is the protocol that actually lets us transfer files. It can facilitate this between any two machines using it. But FTP is not just a protocol but it is also a program.FTP promotes sharing of files via remote computers with reliable and efficient data transfer. The Port number for FTP is 20 for data and 21 for control.  Command   ftp machinename

4. 3. TFTP: The Trivial File Transfer Protocol (TFTP) is the stripped-down, stock version of FTP, but it’s the protocol of choice if you know exactly what you want and where to find it. It’s a technology for transferring files between network devices and is a simplified version of FTP. The Port number for TFTP is 69. Command   tftp [ options... ] [host [port]] [-c command]

5. 4. NFS: It stands for a network file system. It allows remote hosts to mount file systems over a network and interact with those file systems as though they are mounted locally. This enables system administrators to consolidate resources onto centralized servers on the network. The Port number for NFS is 2049. Command   service nfs start

6. 5 . SMTP: It stands for Simple Mail Transfer Protocol. It is a part of the TCP/IP protocol. Using a process called “store and forward,” SMTP moves your email on and across networks. It works closely with something called the Mail Transfer Agent (MTA) to send your communication to the right computer and email inbox. The Port number for SMTP is 25.  Command   MAIL FROM:<[email protected]?

7. 6. LPD: It stands for Line Printer Daemon. It is designed for printer sharing. It is the part that receives and processes the request. A “daemon” is a server or agent. The Port number for LPD is 515.  Command   lpd [ -d ] [ -l ] [ -D DebugOutputFile ]

8. 7. X window: It defines a protocol for the writing of graphical user interface–based client/server applications. The idea is to allow a program, called a client, to run on one computer. It is primarily used in networks of interconnected mainframes. Port number for X window starts from 6000 and increases by 1 for each server. Command    Run xdm in runlevel 5

9. 8. SNMP: It stands for Simple Network Management Protocol. It gathers data by polling the devices on the network from a management station at fixed or random intervals, requiring them to disclose certain information. It is a way that servers can share information about their current state, and also a channel through which an administrate can modify pre-defined values. The Port number of SNMP is 161(TCP) and 162(UDP).    Command    snmpget - mALL -v1 - cpublic snmp_agent_Ip_address sysName.0

10. 9. DNS: It stands for Domain Name System. Every time you use a domain name, therefore, a DNS service must translate the name into the corresponding IP address. For example, the domain name www.abc.com might translate to 198.105.232.4.  The Port number for DNS is 53.    Command    ipconfig / flushdns

11. 10. DHCP: It stands for Dynamic Host Configuration Protocol (DHCP). It gives IP addresses to hosts. There is a lot of information a DHCP server can provide to a host when the host is registering for an IP address with the DHCP server. Port number for DHCP is 67, 68.  Command   clear ip dhcp binding {address | * }

12. Presentation Layer Protocols: Apple Filing Protocol (AFP):  Apple Filing Protocol is the proprietary network protocol (communications protocol) that offers services to macOS or the classic macOS . This is basically the network file control protocol specifically designed for Mac-based platforms. Lightweight Presentation Protocol (LPP):  Lightweight Presentation Protocol is that protocol which is used to provide ISO presentation services on the top of TCP/IP based protocol stacks. NetWare Core Protocol (NCP):  NetWare Core Protocol is the network protocol which is used to access file, print, directory, clock synchronization, messaging, remote command execution and other network service functions. Network Data Representation (NDR):  Network Data Representation is basically the implementation of the presentation layer in the OSI model, which provides or defines various primitive data types, constructed data types and also several types of data representations .

13. External Data Representation (XDR):  External Data Representation (XDR) is the standard for the description and encoding of data. It is useful for transferring data between computer architectures and has been used to communicate data between very diverse machines. Converting from local representation to XDR is called encoding, whereas converting XDR into local representation is called decoding. Secure Socket Layer (SSL):  The Secure Socket Layer protocol provides security to the data that is being transferred between the web browser and the server. SSL encrypts the link between a web server and a browser, which ensures that all data passed between them remains private and free from attacks.

14. Session Layer Protocols : AppleTalk Data Stream Protocol (ADSP):  ADSP is that type of protocol which was developed by Apple Inc. and it includes a number of features that allow local area networks to be connected with no prior setup. This protocol was released in 1985.  This protocol rigorously followed the OSI model of protocol layering. ADSP itself has two protocols named: AppleTalk Address Resolution Protocol (AARP) and Name Binding Protocol (NBP), both aimed at making system self-configuring. Real-time Transport Control Protocol (RTCP):  RTCP is a protocol which provides out-of-band statistics and control information for an RTP (Real-time Transport Protocol) session. RTCP’s primary function is to provide feedback on the quality of service ( QoS ) in media distribution by periodically sending statistical information such as transmitted octet and packet counts or packet loss to the participants in the streaming multimedia session. Point-to-Point Tunneling Protocol (PPTP):  PPTP is a protocol which provides a method for implementing virtual private networks. PPTP uses a TCP control channel and a Generic Routing Encapsulation tunnel to encapsulate PPP (Point-to-Point Protocol) packets This protocol provides security levels and remote access levels comparable with typical VPN (Virtual Private Network) products.

15. Password Authentication Protocol (PAP):  Password Authentication Protocol is a password-based authentication protocol used by Point to Point Protocol (PPP) to validate users. Almost all network operating systems, remote servers support PAP. PAP authentication is done at the time of the initial link establishment and verifies the identity of the client using a two-way handshake (Client-sends data and server in return sends Authentication-ACK (Acknowledgement) after the data sent by client is verified completely). Remote Procedure Call Protocol (RPCP):  Remote Procedure Call Protocol (RPCP) is a protocol that is used when a computer program causes a procedure (or a sub-routine) to execute in a different address space without the programmer explicitly coding the details for the remote interaction. This is basically the form of client-server interaction, typically implemented via a request-response message-passing system.

16. Sockets Direct Protocol (SDP):  Sockets Direct Protocol (SDP) is a protocol that supports streams of sockets over Remote Direct Memory Access (RDMA) network fabrics. The purpose of SDP is to provide an RDMA-accelerated alternative to the TCP protocol. The primary goal is to perform one particular thing in such a manner which is transparent to the application.

17. Transport layer protocols TCP (Transmission Control Protocol) :   TCP is a layer 4 protocol which provides acknowledgement of the received packets and is also reliable as it resends the lost packets. It is better than UDP but due to these features it has an additional overhead. It is used by application protocols like HTTP and FTP.  UDP (User Datagram Protocol) :   UDP is also a layer 4 protocol but unlike TCP it doesn’t provide acknowledgement of the sent packets. Therefore, it isn’t reliable and depends on the higher layer protocols for the same. But on the other hand it is simple, scalable and comes with lesser overhead as compared to TCP. It is used in video and voice streaming. 

18. TCP Vs UDP –   Session Multiplexing:   A single host with a single IP address is able to communicate with multiple servers. While using TCP, first a connection must be established between the server and the receiver and the connection is closed when the transfer is completed. TCP also maintains reliability while the transfer is taking place. UDP on the other hand sends no acknowledgement of receiving the packets. Therefore, provides no reliability.    Segmentation:   Information sent is first broken into smaller chunks for transmission. Maximum Transmission Unit or MTU of a Fast Ethernet is 1500 bytes whereas the theoretical value of TCP is 65495 bytes. Therefore, data has to be broken into smaller chunks before being sent to the lower layers. MSS or Maximum Segment Size should be set small enough to avoid fragmentation. TCP supports MSS and Path MTU discovery with which the sender and the receiver can automatically determine the maximum transmission capability.  UDP doesn’t support this; therefore it depends on the higher layer protocols for data segmentation.   

19. Flow Control:   If sender sends data faster than what receiver can process then the receiver will drop the data and then request for a retransmission, leading to wastage of time and resources. TCP provides end-to-end flow control which is realized using a sliding window. The sliding window sends an acknowledgement from receiver’s end regarding the data that the receiver can receive at a time. UDP doesn’t implement flow control and depends on the higher layer protocols for the same.    Connection Oriented:   TCP is connection oriented, i.e., it creates a connection for the transmission to take place, and once the transfer is over that connection is terminated. UDP on the other hand is connectionless just like IP (Internet Protocol).   

20. Reliability:   TCP sends an acknowledgement when it receives a packet. It requests a retransmission in case a packet is lost. UDP relies on the higher layer protocols for the same.         6.  Headers:     The size of TCP header is 20-bytes (16-bits for source port, 16-bits for the destination port, 32-bits for seq number, 32-bits for ack number, 4-bits header length) The size of the UDP header is 8-bytes (16-bits for source port, 16-bits for destination port, 16-bits for length, 16-bits for checksum); it’s significantly smaller than the TCP header. Both UDP and TCP header is comprised of 16-bit Source port(these are used for identifying the port number of the source) fields and 16-bits destination port (these are used for specifying the offered application) fields.

21. Network layer protocol TCP/IP supports the following protocols: ARP ARP stands for Address Resolution Protocol. It is used to associate an IP address with the MAC address. Each device on the network is recognized by the MAC address imprinted on the NIC. Therefore, we can say that devices need the MAC address for communication on a local area network. MAC address can be changed easily. For example, if the NIC on a particular machine fails, the MAC address changes but IP address does not change. ARP is used to find the MAC address of the node when an internet address is known.

22. How ARP works If the host wants to know the physical address of another host on its network, then it sends an ARP query packet that includes the IP address and broadcast it over the network. Every host on the network receives and processes the ARP packet, but only the intended recipient recognizes the IP address and sends back the physical address. The host holding the datagram adds the physical address to the cache memory and to the datagram header, then sends back to the sender.

23. Steps taken by ARP protocol If a device wants to communicate with another device, the following steps are taken by the device: The device will first look at its internet list, called the ARP cache to check whether an IP address contains a matching MAC address or not. It will check the ARP cache in command prompt by using a command  arp -a .

24. If ARP cache is empty, then device broadcast the message to the entire network asking each device for a matching MAC address . The device that has the matching IP address will then respond back to the sender with its MAC address Once the MAC address is received by the device, then the communication can take place between two devices. If the device receives the MAC address, then the MAC address gets stored in the ARP cache. We can check the ARP cache in command prompt by using a command arp -a.

25. RARP RARP stands for  Reverse Address Resolution Protocol . If the host wants to know its IP address, then it broadcast the RARP query packet that contains its physical address to the entire network. A RARP server on the network recognizes the RARP packet and responds back with the host IP address. The protocol which is used to obtain the IP address from a server is known as  Reverse Address Resolution Protocol . The message format of the RARP protocol is similar to the ARP protocol. Like ARP frame, RARP frame is sent from one machine to another encapsulated in the data portion of a frame.

26. ICMP ICMP stands for Internet Control Message Protocol. The ICMP is a network layer protocol used by hosts and routers to send the notifications of IP datagram problems back to the sender. ICMP uses echo test/reply to check whether the destination is reachable and responding. ICMP handles both control and error messages, but its main function is to report the error but not to correct them. An IP datagram contains the addresses of both source and destination, but it does not know the address of the previous router through which it has been passed. Due to this reason, ICMP can only send the messages to the source, but not to the immediate routers. ICMP protocol communicates the error messages to the sender. ICMP messages cause the errors to be returned back to the user processes. ICMP messages are transmitted within IP datagram.

27. The Format of an ICMP message The first field specifies the type of the message. The second field specifies the reason for a particular message type. The checksum field covers the entire ICMP message.

28. Internet Protocol Version 4 (IPv4) IPv4 is 32-bit addressing scheme used as TCP/IP host addressing mechanism. IP addressing enables every host on the TCP/IP network to be uniquely identifiable. IPv4 provides hierarchical addressing scheme which enables it to divide the network into sub-networks, each with well-defined number of hosts. IP addresses are divided into many categories: Class A   - it uses first octet for network addresses and last three octets for host addressing Class B   - it uses first two octets for network addresses and last two for host addressing Class C   - it uses first three octets for network addresses and last one for host addressing Class D   - it provides flat IP addressing scheme in contrast to hierarchical structure for above three. Class E   - It is used as experimental. IPv4 also has well-defined address spaces to be used as private addresses (not routable on internet), and public addresses (provided by ISPs and are routable on internet). Though IP is not reliable one; it provides ‘Best-Effort-Delivery’ mechanism.

29. Internet Protocol Version 6 (IPv6) Exhaustion of IPv4 addresses gave birth to a next generation Internet Protocol version 6. IPv6 addresses its nodes with 128-bit wide address providing plenty of address space for future to be used on entire planet or beyond. IPv6 has introduced Anycast addressing but has removed the concept of broadcasting. IPv6 enables devices to self-acquire an IPv6 address and communicate within that subnet. This auto-configuration removes the dependability of Dynamic Host Configuration Protocol (DHCP) servers. This way, even if the DHCP server on that subnet is down, the hosts can communicate with each other. IPv6 provides new feature of IPv6 mobility. Mobile IPv6 equipped machines can roam around without the need of changing their IP addresses. IPv6 is still in transition phase and is expected to replace IPv4 completely in coming years. At present, there are few networks which are running on IPv6. There are some transition mechanisms available for IPv6 enabled networks to speak and roam around different networks easily on IPv4. These are: Dual stack implementation Tunneling NAT-PT

30. IGMP IGMP stands for  Internet Group Message Protocol . The IP protocol supports two types of communication: Unicasting :  It is a communication between one sender and one receiver. Therefore, we can say that it is one-to-one communication. Multicasting:  Sometimes the sender wants to send the same message to a large number of receivers simultaneously. This process is known as multicasting which has one-to-many communication. The IGMP protocol is used by the hosts and router to support multicasting. The IGMP protocol is used by the hosts and router to identify the hosts in a LAN that are the members of a group.

31. IGMP is a part of the IP layer, and IGMP has a fixed-size message. The IGMP message is encapsulated within an IP datagram.

32. The Format of IGMP message

33. Data link layer protocols Synchronous Data Link Protocol (SDLC)   – SDLC is basically a communication protocol of computer. It usually supports multipoint links even error recovery or error correction also. It is usually used to carry SNA (Systems Network Architecture) traffic and is present precursor to HDLC. It is also designed and developed by IBM in 1975. It is also used to connect all of the remote devices to mainframe computers at central locations may be in point-to-point (one-to-one) or point-to-multipoint (one-to-many) connections. It is also used to make sure that the data units should arrive correctly and with right flow from one network point to next network point.

34. High-Level Data Link Protocol (HDLC)  – HDLC is basically a protocol that is now assumed to be an umbrella under which many Wide Area protocols sit. It is also adopted as a part of X.25 network. It was originally created and developed by ISO in 1979. This protocol is generally based on SDLC. It also provides best-effort unreliable service and also reliable service. HDLC is a bit-oriented protocol that is applicable for point-to-point and multipoint communications both.

35. Serial Line Interface Protocol (SLIP)  – SLIP is generally an older protocol that is just used to add a framing byte at end of IP packet. It is basically a data link control facility that is required for transferring IP packets usually among Internet Service Providers (ISP) and a home user over a dial-up link. It is an encapsulation of the TCP/IP especially designed to work with over serial ports and several router connections simply for communication. It is some limitations like it does not provide mechanisms such as error correction or error detection.

36. Point to Point Protocol (PPP)  – PPP is a protocol that is basically used to provide same functionality as SLIP. It is most robust protocol that is used to transport other types of packets also along with IP Packets. It can also be required for dial-up and leased router-router lines. It basically provides framing method to describe frames. It is a character-oriented protocol that is also used for error detection. It is also used to provides two protocols i.e. NCP and LCP. LCP is used for bringing lines up, negotiation of options, bringing them down whereas NCP is used for negotiating network-layer protocols. It is required for same serial interfaces like that of HDLC.

37. Link Control Protocol (LCP) – It was originally developed and created by IEEE 802.2. It is also used to provide HDLC style services on LAN (Local Area Network). LCP is basically a PPP protocol that is used for establishing, configuring, testing, maintenance, and ending or terminating links for transmission of data frames.

38. Link Access Procedure (LAP) – LAP protocols are basically a data link layer protocols that are required for framing and transferring data across point-to-point links. It also includes some reliability service features. There are basically three types of LAP i.e. LAPB (Link Access Procedure Balanced), LAPD (Link Access Procedure D-Channel), and LAPF (Link Access Procedure Frame-Mode Bearer Services). It is actually originated from IBM SDLC, which is being submitted by IBM to the ISP simply for standardization.

39. Network Control Protocol (NCP) – NCP was also an older protocol that was implemented by ARPANET. It basically allows users to have access to use computers and some of the devices at remote locations and also to transfer files among two or more computers. It is generally a set of protocols that is forming a part of PPP. NCP is always available for each and every higher-layer protocol that is supported by PPP. NCP was replaced by TCP/IP in the 1980s.

40. Physical layer protocols Examples of protocols that use physical layers include: Digital Subscriber Line. Integrated Services Digital Network. Infrared Data Association. Universal Serial Bus (USB.)

41. Digital Subscriber Line ( DSL,  originally ,  digital subscriber loop ) is a communication medium, which is used to transfer internet through copper wire telecommunication line. Along with cable internet, DSL is one of the most popular ways  ISPs  provide broadband internet access.    Its aim is to maintain the high speed of the internet being transferred. If we ask that how we gonna achieve such a thing i.e., both telephone and internet facility, then the answer is by using  splitters or DSL filters (shown in the below diagram). Basically, the use  splitter  is to splits the frequency and make sure that they can’t get interrupted.  

42. Integrated Services Digital Network These are a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the traditional circuits of the public switched telephone network. Before  Integrated Services Digital Network (ISDN) , the telephone system was seen as a way to transmit voice, with some special services available for data. The main feature of ISDN is that it can integrate speech and data on the same lines, which were not available in the classic telephone system. ISDN is a circuit-switched telephone network system, but it also provides access to packet-switched networks that allows digital transmission of voice and data. This results in potentially better voice or data quality than an analog phone can provide. It provides a packet-switched connection for data in increments of 64 kilobit/s. It provided a maximum of 128 kbit /s bandwidth in both upstream and downstream directions. A greater data rate was achieved through channel bonding. Generally, ISDN B-channels of three or four BRIs (six to eight 64 kbit /s channels) are bonded .

43. ISDN Interfaces: The following are the interfaces of ISDN : Basic Rate Interface (BRI) – There are two data-bearing channels (‘B’ channels) and one signaling channel (‘D’ channel) in BRI to initiate connections. The B channels operate at a maximum of 64 Kbps while the D channel operates at a maximum of 16 Kbps. The two channels are independent of each other. For example, one channel is used as a TCP/IP connection to a location while the other channel is used to send a fax to a remote location. In iSeries ISDN supports a basic rate interface ( BRl ). The basic rate interface ( BRl ) specifies a digital pipe consisting of two B channels of 64 Kbps each and one D channel of 16 Kbps. This equals a speed of 144 Kbps. In addition, the BRl service itself requires an operating overhead of 48 Kbps. Therefore a digital pipe of 192 Kbps is required . Primary Rate Interface (PRI) – Primary Rate Interface service consists of a D channel and either 23 or 30 B channels depending on the country you are in. PRI is not supported on the iSeries . A digital pipe with 23 B channels and one 64 Kbps D channel is present in the usual Primary Rate Interface (PRI). Twenty-three B channels of 64 Kbps each and one D channel of 64 Kbps equals 1.536 Mbps. The PRI service uses 8 Kbps of overhead also. Therefore PRI requires a digital pipe of 1.544 Mbps . Broadband-ISDN (B-ISDN) – Narrowband ISDN has been designed to operate over the current communications infrastructure, which is heavily dependent on the copper cable however B-ISDN relies mainly on the evolution of fiber optics. According to CCITT B-ISDN is best described as ‘a service requiring transmission channels capable of supporting rates greater than the primary rate.

44. Infrared Data Association , or IrDA in short, is a group of device manufacturers that developed a standard for transmitting data via infrared (IR) light waves. It provides specifications for the complete set of protocols for wireless IR communication. The main reason for using IrDA had been wireless data transfer over the “last one meter” using point-and-shoot principles. It is famous for secure data transfer, line-of-sight and very low bit error rate that makes it very efficient [ 1 ]. IR communication is an inexpensive and widely adopted short-range (1-3m) wireless technology. It is widely used in  consumer electronics ,  automobiles , computers, medical devices, household appliances, commercial services, etc.

45. Universal Serial Bus (USB) is a set of connectivity specifications developed in collaboration with industry leaders. Originally released in 1995 at just 12 Mbps, USB allows easy, high-speed connections of peripherals to PCs that, once plugged in, configure automatically.