Computer Networks and Data Communication - LEC5 TCP/IP Protocol Suite PDF

TCP/IP PROTOCOL SUITE Transmission Control Protocol/Internet Protocol. ▪ TCP/IP is open standard protocol  Not tied to one vendor ▪ TCP/IP is the internet protocol ▪ Now internet use TCP/IP v4 ▪ Next version TCP/IP v6 TCP/IP  TCP/IP is a hierarchical protocol made up of inter...

TCP/IP PROTOCOL SUITE Transmission Control Protocol/Internet Protocol. ▪ TCP/IP is open standard protocol  Not tied to one vendor ▪ TCP/IP is the internet protocol ▪ Now internet use TCP/IP v4 ▪ Next version TCP/IP v6 TCP/IP  TCP/IP is a hierarchical protocol made up of interactive modules, each of which provides a specific functionality  the layers of the TCP/IP protocol suite contain relatively independent protocols that can be mixed and matched depending on the needs of the system.  At the transport layer, TCP/IP defines three protocols: Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and Stream Control Transmission Protocol (SCTP).  At the network layer, the main protocol defined by TCP/IP is the Internetworking Protocol (IP); there are also some other protocols that support data movement in this layer. Some Protocols in TCP/IP Suite TCP/IP Advantages and Disadvantages  Advantages – Standard – Direct access to the Internet – Routable – Cross Platform  Disadvantages – Difficulty of setup – Slower than other protocols Network Access Layer TCP/IP Protocol Architecture  Network Access Layer  Physical Layer  Transmission medium  Signal rate  Datalink Layer  Logical interface between end system and network  Hop to Hop addressing  Error detection Mechanism TCP/IP Protocol Architecture Cont.  Internet Layer (IP Layer)  Network layer protocol  Packet in the IP layer is called Datagram  Datagram consist of TWO parts  Header  Data  Routing of data  Logical addressing IPV4 , IPV6  At the network layer (or, more accurately, the internetwork layer), TCP/IP supports the Internetworking Protocol. IP, in turn, uses four supporting protocols: ARP, RARP, ICMP, and IGMP. Internetworking Protocol (IP)  The Internetworking Protocol (IP) is the transmission mechanism used by the TCP/IP protocols.  It is an unreliable and connectionless protocol-a best-effort delivery service.  The term best effort means that IP provides no error checking or tracking.  IP transports data in packets called datagrams, each of which is transported separately.  Datagrams can travel along different routes and can arrive out of sequence or be duplicated.  IP does not keep track of the routes and has no facility for reordering datagrams once they arrive at their destination Address Resolution Protocol (ARP)  The Address Resolution Protocol (ARP) is used to associate a logical address with a physical address  ARP is used to find the physical address of the node when its Internet address is known arp -a Arp -a ARP operation ARP operation  Sending Data: When a device (computer, printer, etc.) needs to send data to another device on the same network, it first needs the MAC address of the destination device. . ARP Request: The sending device broadcasts an ARP request packet on the network. This packet contains the IP address of the destination device and asks for its corresponding MAC address.  Responding Device: Any device on the network that recognizes the requested IP address in the ARP request packet will respond with an ARP reply packet. This reply contains the MAC address associated with the requested IP address.  MAC Address Obtained: The sending device receives the ARP reply and stores the MAC address of the destination device in its ARP cache for future reference.  Sending the Data: The sending device can now use the obtained MAC address to encapsulate the data packet and send it directly to the intended recipient. Reverse Address Resolution Protocol RARP  The Reverse Address Resolution Protocol (RARP) allows a host to discover its Internet address when it knows only its physical address.  Itis used when a computer is connected to a network for the first time Internet Control Message Protocol ICMP  The Internet Control Message Protocol (ICMP) is a mechanism used by hosts and gateways to send notification of datagram problems back to the sender. ICMP sends query and error reporting messages  ICMP → Ping  Ping is a command line utility in Microsoft Windows.  Ping allows you to check connectivity with other devices  Ping is a tool of DOS attack  Tray in your lab Ping IP Ping URL Ping IP -l Ping IP -n Ping IP -t Internet Group Message Protocol  The Internet Group Message Protocol (IGMP) is used to facilitate the simultaneous transmission of a message to a group of recipients Transport Layer Transport Layer  Traditionally the transport layer was represented in TCP/IP by two protocols: TCP and UDP.  UDP and TCP are transport level protocols responsible for delivery of a message from a process (running program) to another process.  A new transport layer protocol, Stream Control Transmission Protocol( SCTP), has been devised to meet the needs of some new applications. TCP  At the sending end of each transmission, TCP divides a stream of data into smaller units called segments.  Each segment includes a sequence number for reordering after receipt, together with an acknowledgment number for the segments received. Segments are carried across the internet inside of IP datagrams.  At the receiving end, TCP collects each datagram as it comes in and reorders the transmission based on sequence numbers. TCP is discussed in Chapter 23 TCP Characteristics  Transmission Control Protocol  Transport layer protocol  Use port numbers  Reliable (Acknowledgement of receipt)  Connection oriented(synchronization)  Full duplex  Error control(Error checking(checksum )  Flow control  Data-recovery features  Sequencing of data packets PORTS 1-In TCP / IP information send from the Port in the source computer to the Port in the destination computer according to Port number which software used it 2-Each program has a certain port works in contact 3-Each port is a number 16bit and thus take values from zero up to 65535 4-These ports are divided into TCP Ports and UDP Ports according to the protocol that is running on port 5-All servers that connect to the Telnet service that uses the Port 23, a TCP Port 6-All Web servers running on port 80 TCP Client Server Created By Shereen Khalaf 3/10/2022 Flow Control TCP Acknowledgment UDP Characteristics  User Datagram Protocol  Transport layer protocol  Process to process communication – Use port numbers  Connectionless (no notification)  Unreliable  Perform very limited error checking  Very simple using a minimum of overhead  Provides best-effort delivery   The data may be dropped due to: Routing Error,  Duplicate data due to redundancy Data loss in its way due to TTL.  Has no data-recovery features TCP (Reliable) vs. UDP (Best-Effort Comparison) Stream Control Transmission Protocol  The Stream Control Transmission Protocol (SCTP) provides support for newer applications such as voice over the Internet(VOIP).  It is a transport layer protocol that combines the best features of UDP and TCP. We discuss SCTP in Chapter 23 Application Layer Application Layer  The application layer in TCPIIP is equivalent to the combined session, presentation, and application layers in the OSI modeL Many protocols are defined at this layer. Application Layer Protocol 1 - SNMP Simple Network Management Protocol This protocol is used by network administrators to see additional information on the network and also the devices on your network Switches and Routers and any other devices 2 – FTP File Transfer Protocol Is important tool for transferring files over the network and between devices that support this technology 3 – TFTP Trivial File Transfer Protocol A miniature version of FTP is used to transfer the Boot Image for devices that do not have Boot Disk And also to and from the Routers - Application Layer Protocol 4 SMTP Simple Mail Transfer Protocol transfer of electronic messages over the network and device to another device, and transfer Emails 5 – POP Post Office Protocol It provides storage space for receiving electronic messages 6 – IMAP Internet Mail Access Protocol It provides storage space for the user to store messages and also read the Email Header The store is part of the message on the Server Is used in Yahoo 7 – Telnet Terminal currencies This allows remote communication devices on the network 8. SSH 9 - HTTP Hypertext Transfer Protocol It is a way to communicate between devices and the Web Servers And used in open sites on the Internet Browser 10. HTTPs 11 - NTP Network Time Protocol The primary purpose is to make all devices in the network operates one time or Synchronize. 12- DNS domain name system It is an application layer protocol used to provide a human-friendly naming mechanism for internet resources. It is what ties a domain name to an IP address and allows you to access sites by name in your browser. 13- DHCP The Dynamic Host Configuration Protocol (DHCP) has been devised to provide static and dynamic address allocation that can be manual or automatic  A DHCP server has a database that statically binds physical addresses to IP addresses.  Dynamic Address Allocation DHCP has a second database with a pool of available IP addresses.  This second database makes DHCP dynamic. When a DHCP client requests a temporary IP address, the DHCP server goes to the pool of available (unused) IP addresses and assigns an IP address for a negotiable period of time. 14. BOOTP The Bootstrap Protocol (BOOTP) is a client/server protocol designed to provide physical address to logical address mapping. BOOTP is an application layer protocol ADDRESSING ADDRESSING Relationship of layers and addresses in TCPIIP Port Addresses  The end objective of Internet communication is a process communicating with another process.  For example, computer A can communicate with computer C by using TELNET. At the same time, computer A communicates with computer B by using the File Transfer Protocol (FTP).  For these processes to receive data simultaneously, we need a method to label the different processes.  In other words, they need addresses. In the TCPIIP architecture, the label assigned to a process is called a port address. A port address in TCPIIP is 16 bits in length. Port Addresses Cont.  Figure 2.21 shows two computers communicating via the Internet. The sending computer is running three processes at this time with port addresses a, b, and c. The receiving computer is running two processes at this time with port addresses j and k.  Process a in the sending computer needs to communicate with process j in the receiving computer.  To show that data from process a need to be delivered to process j, and not k, the transport layer encapsulates data from the application layer in a packet and adds two port addresses (a and j), source and destination.  The packet from the transport layer is then encapsulated in another packet at the network layer with logical source and destination addresses (A and P).  Finally, this packet is encapsulated in a frame with the physical source and destination addresses of the next hop. Specific Addresses  Some applications have user-friendly addresses that are designed for that specific address.  Examples include the e-mail address (for example, [email protected]) and the Universal Resource Locator (URL) (for example, www.mhhe.com).  The first defines the recipient of an e-mail (see Chapter 26); the second is used to find a document on the World Wide Web (see Chapter 27).  These addresses, however, get changed to the corresponding port and logical addresses by the sending computer(DNS), as we will see in Chapter 25