Transmission Control Protocol (TCP)

50 %
50 %
Information about Transmission Control Protocol (TCP)
Education

Published on May 24, 2009

Author: ankush85

Source: authorstream.com

The Transmission Control Protocol (TCP) : The Transmission Control Protocol (TCP) The Transmission Control Protocol (TCP) : The Transmission Control Protocol (TCP) TCP is a protocol that specifies: How to distinguish among multiple destinations on a given machine How to initiate and terminate a stream transfer Format of the data and acknowledgments that two computers exchange to achieve a reliable transfer Procedures the computers use to ensure that the data arrives correctly Distinguishing AmongMultiple Destinations : Distinguishing AmongMultiple Destinations Like UDP, TCP uses protocol ports to identify the ultimate destination within a machine Unlike UDP, TCP defines a connection as the fundamental abstraction for data transfer Connection: Virtual circuit Identified by a pair of endpoints Initiating Stream Transfers : Initiating Stream Transfers Virtual Circuit - simulate a circuit switched network over a packet-switched network Sender and receiver interact before transfer begins to set up the connection Once the connection is established a stream transfer can begin During the transfer, protocol software on the two machines communicate to ensure that data is delivered correctly Upon completion of the transfer the connection is closed Initiating Stream Transfers (cont) : Initiating Stream Transfers (cont) An endpoint for a TCP connection is defined by a (host, port) pair Host = the IP address of for a host Port = a TCP port on that host A TCP connection is defined by a pair of endpoints: Port 1037 on www.whitehouse.gov and port 76 on viper.cs.virginia.edu: (198.137.240.91, 1037) and (128.143.137.17, 76) Initiating Stream Transfers (cont) : Initiating Stream Transfers (cont) Multiple connections to same host: Port 1037 on www.whitehouse.gov and port 76 on viper.cs.virginia.edu: (198.137.240.91, 1037) and (128.143.137.17, 76) Port 355 on falcon.cs.jmu.edu and port 801 on viper.cs.virginia.edu: (134.126.10.30, 355) and (128.143.137.17, 801) Initiating Stream Transfers (cont) : Initiating Stream Transfers (cont) Multiple connections to same port: Port 1037 on www.whitehouse.gov and port 444 on viper.cs.virginia.edu: (198.137.240.91, 1037) and (128.143.137.17, 444) Port 355 on falcon.cs.jmu.edu and port 444 on viper.cs.virginia.edu: (134.126.10.30, 355) and (128.143.137.17, 444) No ambiguity - connection identified by both endpoints Initiating Stream Transfers (cont) : Initiating Stream Transfers (cont) Both endpoints must agree to participate: Passive open - one application program contacts its O.S. and indicates that it will accept an incoming connection Active open - application program at other end contacts its O.S. and requests a connection Both TCP software modules cooperate to establish a connection Application programs can transmit data (TCP provides reliability) TCP Data Stream Format : TCP Data Stream Format Data from application programs is a sequence of octets (with no type associated) TCP divides data into segments for transmission Usually, each segment travels across the internet in a single IP datagram Review: Unreliable PacketDelivery Service : Review: Unreliable PacketDelivery Service Benefits: Fast Cost-effective Drawbacks: Packet loss, corruption, delay, duplication, out-of-order delivery Sender might transmit faster than receiver can receive Dictates a set packet size The Need for a Reliable Stream Delivery Service : The Need for a Reliable Stream Delivery Service Application-level programmers don’t want: To have to provide reliability in each application To be constrained by fixed-size packets Application-level programmers do want: Reliability Unstructured, stream-oriented service Full duplex virtual circuit connection Buffered transfer Providing Reliability with Acknowledgments and Retransmissions : Providing Reliability with Acknowledgments and Retransmissions Packet Loss : Packet Loss Sender Network Receiver Send packet 1 Send packet 1 Receive ACK 1 Receive packet 1 Send ACK 1 (Timeout) ACK Loss : ACK Loss Sender Network Receiver Send packet 1 Send packet 1 Receive ACK 1 (Timeout) Send ACK 1 Receive packet 1 Receive packet 1 Send ACK 1 (Discard) ACK Delayed : ACK Delayed Sender Network Receiver Send packet 1 Receive ACK 1 Receive ACK 1 (Timeout) Send packet 1 (Discard) Send ACK 1 Receive packet 1 Receive packet 1 Send ACK 1 (Discard) A Problem : A Problem A simple positive acknowledgment protocol wastes a substantial amount of network bandwidth because it must delay sending a new packet until it receives an acknowledgment for the previous packet. A Solution : A Solution Sender Network Receiver Sliding Windows : Sliding Windows All packets inside the window can be transmitted When an acknowledgment for packet 1 is received the window slides to the right and allows the transmission of packet 9: window Sliding Windows (cont) : Sliding Windows (cont) Receiver must keep a sliding window as well: After packet 1 is received and acknowledged: Sliding Windows (cont) : Sliding Windows (cont) Conceptually partitions the packets into three classes: Transmitted, received, and acknowledged packets (outside and left of sliding window) Packets being transmitted (inside the window) Packets waiting to be transmitted (outside and right of sliding window) Sliding Windows (cont) : Sliding Windows (cont) Only unacknowledged packets are retransmitted Keep separate timer for each packet Performance: Depends on the window size and the speed of the underlying network Note: sliding window protocol with window size = 1 is the same as the simple positive acknowledgment protocol we saw earlier Sliding Windows: Performance : Sliding Windows: Performance Tuning the sliding window protocol Increase window size so that sender is transmitting packets as fast as the network can carry them Eliminates network idle time Increases throughput (as compared to the simple positive acknowledgment protocol) Ideal Sliding Window Performance : Ideal Sliding Window Performance Sender Network Receiver TCP - Efficient Transmission and Flow Control : TCP - Efficient Transmission and Flow Control Uses a specialized sliding window mechanism Multiple segments can be sent before an acknowledgment arrives Efficient transmission Allows receiver to restrict transmission until it has sufficient buffer space to accommodate more data Flow control TCP Sliding Windows : TCP Sliding Windows Operates at the octet level Octets of the data stream are numbered sequentially Octets 1&2 have been sent and acknowledged Octets 3-6 sent but not acknowledged Octets 7&8 can be sent TCP Sliding Windows : TCP Sliding Windows Four per (full duplex) connection: A sends to B A receives from B B sends to A B receives from A TCP Sliding Windows - Flow Control : TCP Sliding Windows - Flow Control Each window can vary in size over time Each ACK contains a window advisement Specifies how many additional octets of data the receiver is willing to accept Sender increases or decreases sending window sized based on the receiver’s advise Provides end-to-end flow control TCP Sliding Windows - Flow Control Example : TCP Sliding Windows - Flow Control Example Sender transmits 3 octets Receives an ACK 3 with window advisement = 3 Sender transmits 1 octet 1 2 3 4 5 6 7 8 9 11 12 13 1 2 3 4 5 6 7 8 9 11 12 13 TCP Sliding Windows - Flow Control Example (cont) : TCP Sliding Windows - Flow Control Example (cont) Receives an ACK 4 with window advisement = 7 Sender transmits 4 octets Receives an ACK 8 with window advisement = 4 1 2 3 4 5 6 7 8 9 11 12 13 Summary : Summary TCP is a transport protocol that specifies: How to distinguish among multiple destinations on a given machine How to initiate and terminate a stream transfer Format of the data and acknowledgments that two computers exchange to achieve a reliable transfer Procedures the computers use to ensure that the data arrives correctly

Add a comment

Related presentations

Related pages

Transmission Control Protocol – Wikipedia

Das Transmission Control Protocol (TCP, engl., zu deutsch Übertragungssteuerungsprotokoll) ist ein Netzwerkprotokoll, das definiert, auf welche Art und ...
Read more

Transmission Control Protocol - Wikipedia, the free ...

TCP protocol operations may be divided into three phases. Connections must be properly established in a multi-step handshake process (connection ...
Read more

TCP - Transmission Control Protocol

Elektronik-Kompendium.de > Netzwerktechnik. TCP - Transmission Control Protocol. Das Transmission Control Protocol, kurz TCP, ist Teil der Protokollfamilie ...
Read more

Transmission Control Protocol/Internet Protocol – Wikipedia

Transmission Control Protocol/Internet Protocol (TCP/IP) ist eine Familie von Netzwerkprotokollen und wird wegen ihrer großen Bedeutung für das Internet ...
Read more

TCP :: transmission control protocol :: TCP-Protokoll ...

Das Transmission Control Protocol (TCP) ist ein verbindungsorientiertes Transportprotokoll für den Einsatz in paketvermittelten Netzen. Das Protokoll ...
Read more

Internet protocol suite - Wikipedia, the free encyclopedia

Internet protocol suite; Application layer; BGP; DHCP; DNS; FTP; HTTP; IMAP; ... (ICMP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP ...
Read more

What is TCP (Transmission Control Protocol)? - Definition ...

Read the definition for TCP and learn how the Transmission Control Protocol is used along with the Internet Protocol (IP) to send data and track packets ...
Read more

Transmission Control Protocol (TCP) Parameters

Transmission Control Protocol (TCP) Parameters Last Updated 2016-08-17 Available Formats XML HTML Plain text. Registries included below. TCP Option Kind ...
Read more

Transmission Control Protocol (TCP) - msdn.microsoft.com

TCP-Ports verwenden einen spezifischen Programmport für die Übermittlung von Daten, die mit TCP (Transmission Control Protocol) gesendet werden.
Read more

Transmission Control Protocol - Ask Doc TCP-IP!

All die komischen Standard-Server in /etc/inetd.conf chargen, echo, daytime ... Was sind Pakete, Datagramme, Fragmente? Was zum verwirren. Alles über Ports
Read more