Look At Transmission Control Protocol Information Technology Essay

pure tone At Transmission Control Protocol Information Technology probeTransmission Control Protocol is one most reliable , tie point conversation communicatings protocol hired in the internet traffic .The important aim of this section is to conduct a research on contagion run across protocol informal protocols and find a suited answer to the questions deal the consumes of transmission understand protocol that are non suitable for touchable- judgment of conviction mul beatdia system natural c overing, transmission mold protocol friendly congestion statement for non-transmission control protocol drill etc.I. Features of transmission control protocol non suitable for unfeigned era mul cartridge clipdia system application program.The uses of multimedia applications are increasing daytime to day in the internet traffic. In recent future it is trusted that the real-time multimedia applications increase rapidly and make up a con siderable portion of the total internet band comprehensiveness. transmission control protocol is full duplex, affiliation oriented communication protocol that is use for transmitting selective selective information that chiefly focuses on the accuracy of selective information. however both(prenominal) sustains of TCP are non suitable for real time multimedia application which includes the following.Reliability finished RetransmissionSince TCP is a reliable protocol it uses error control mechanisms like retransmission when an error occurs. Retransmission delay is one of the most important problems in multimedia application for TCP oriented connection. This retransmission is useable in traditional application such as http, FTP, telnet etc which get hold of the injustice free selective information impart between the communicating media. In the pillowcase of multimedia application on that point is an massive emission of data into the network especially in the case of video. This will cause network cong estion, since TCP is a reliable protocol it will bring low the windowpanepanepane size and data emission direct to get out of this congestion. The retransmission causes passim latency which is non suitable for real time multimedia applications where the receiver needs the data at the homogeneous time when the vector sends it. congestion controlIn TCP, the available bandwidth seat be monitored by development congestion algorithm which uses the transmission dictate for the manipulation vector sums in some delibe govern waste. In the cases where there is no congestion, TCP congestion control fairly shares the available bandwidth. Over shorter time scales, the TCP instantaneous rate just looks like a saw- tooth. The cycles are between periods of additive increase separated by multiplicative go down (AIMD). This rate fluctuation is not suitable for multimedia blow application because it affects their smooth functioning.Socket ground application programming larboardThe socke ts based application programming interface does not support multihoming (a technique to improve the reliability of internet connection of an IP network). This result in an application dis process use only a one IP address to a particular TCP connection with another host. In an occasion where the interface associated with that IP address goes down which result in the connection issue and reestablishment. This is not suitable or multimedia applications like VoIP.TCP does not support multicastingIn most of the multimedia communication like phone and video conferencing, the network traffic will be high and heavy(p) amount of data flow across the network. In such situations data are transmitted by using multicasting techniques between the vector and the receivers. But TCP does not support multicastingTCP does not support time stamping.The major problem faced in real time multimedia applications like video and speech sound recording conferencing is the jitter. The major solution for the problem associated with jitter is the use of time stamps. The timestamp at to each one packet shows the time at which each packet is produced when compared with the previous one. So that the receiver knows when each packet is to be played. But unfortunately TCP does not provide support for time stamping.TCP is connection orientedThe TCP is connection-oriented protocol. In this first a connection is established between the source and the destination before data transfer. The main injustice of this connection oriented protocol in real time communication like VoIP is the consumption of resources spent setting up the call. This connection oriented feature made a little crash during connection establishment because it is time taken during certain occasions. Time overhead is not suitable for real time multimedia applications.Do not require full duplex transmissionIn TCP, the processes that reside in the internet establish a reliable serial communication row and exchanges ful l duplex stream of bytes. The processes within the communication are set by the IP addresses. The full duplex connection is not irresponsible for most of the multimedia application. The best example is TV broadcast over LAN in most situations it uses simplex continuous media connection.AcknowledgementIn TCP, there is the need of reference during the transmission of each packet. The positive acknowledgement causes overhead because all packets are sent with a fixed rate. This is not suitable for multimedia.II) UDP is TCP Unfriendly protocolIn order to wrangle about this topic we need to describe the base functions of the TCP and UDP. In order to clearly define about the TCP, UDP unfriendliness we need to understand the basic c at a timepts in detail. With the change magnitude use of real time applications internet users expression for to a greater extent reliable protocol that provide more faster metier for audio and video.Since TCP is a reliable protocol it has the capacity to reduce the amount of data loss, noise and out of sequence data. TCP uses connection based communication between the communicating hosts. This connection based feature of TCP helps in the guaranteed delivery of the packets. It has flow control and congestion control.In the case of UDP, it is unreliable. There is no guarantee for packet delivery and for the sequence. In this protocol there is no connection establishment before the communication starts and it sends the data according to its availability.In real-time communication (for audio or video), both the communicating ends look for speed rather than accuracy. The connection little feature of UDP, that sends the data when they are available and not try to resend once there is an error or packet loss made UDP frequently faster than TCP. This increased speed made more popularity for UDP in streaming media over internet.When compared to TCP the UDP has a main draw backbone, since UDP continuously displace packets with the netw ork without considering there is congestion on the network. It does not take every measures to reduce the congestion in the case where congestion occurs. But TCP make use of the congestion control mechanisms like reduce the transmission rate. Since UDP does not make use of any congestion control algorithms when congestion occurs this tend to take the utilisation of the available bandwidth over the internet. For this reason UDP is cognise as a TCP unfriendly protocol. According to the opinion of Ross (2005, p.198) in his book Computer Networks specifies that UDP is the most commonly used protocol for multimedia application such as Internet phone, real-time video conferencing and streamed of audio and video. So in order to overcome these problems of congestion controls with UDP and improves the band width utilisation and excessively a fair towards competing TCP connection result in the development of new technology called TCP friendly technique. With the increased popularity of the streaming media the UDP traffic becomes a problem for the internet as a whole.III) TCP Friendly congestion control protocolsThe popularity and development of internet leads to the considerable use of real-time multimedia applications like video conferencing, chatting etc. all told these applications make use of non congestion controlled protocols like UDP for transmitting continuous video, audio through the network. This pillow slip of non congestion controlled traffic is called unresponsive flows. The major feature of the unresponsive flow is that they do not reduce their load on the network when there is a packet loss. They continuously transmit the data through the network at the rate with which is encoded without bothering about the network congestion. This type of UDP traffic causes traffic congestion in the network as healthful as it produce an extreme unfairness towards the network. In order to solve these problems, we need to improve the UDP for proper bandwidth utilisat ion, reducing loss ratio and also produce a fair towards the competing TCP connection and this is called as TCP Friendly. In this section we are discussing about the congestion control mechanisms used by TCP friendly protocols like TFRC and TFMC.TFRC (TCP-Friendly Rate Control)TFRC is principally defined as a congestion control mechanism for unicast flows in the Internet. TFRC is evolved from TFRCP protocol and it is mainly used for unicast communication but sometimes it is used for multicast communication with some modifications. The lower variation of throughput over time makes this much more suitable for telephony or streaming media and which has a smooth send rate.TFRC uses equation based congestion control for unicast traffic. In this mechanism it explicitly adjust its sending rate as a function of the mensural rate of loss cores where the loss events contain one or more packet dropped within a RTT. As it follows the equation based congestion control, TFRC directly make use of the TCP throughput equation which makes it possible to deal fairly with TCP. The following is the throughput equation used in the TFRC for congestion controlIn this equationX is the transmit rate in bytes/second.S is the packet size in bytes.R is the round trip time in seconds.B is the no of packets acknowledged by a single TCP acknowledgement.t_RTO is TCP transmission timeout value in seconds.The usual working of the TFRC congestion control mechanism as followsAs the first pure tone the receiver calculate the loss event rate and gives this information back to the sender.Using this data the sender calculates round-trip time (RTT).Using this loss event rate and RTT, calculate acceptable transmit rate using the TFRC throughput equation. in conclusion the sender adjust the transmission rate to match the calculates rate.By using the receiver based mechanism TFRC is sound suited for applications like the sender are a large server handling many synchronic connections and receiver is has more memory and CPU cycles available for computation.TFMC (TCP friendly Multicast Congestion Control)TFMC is the single rate congestion control scheme for multicast transmission. TFMC is single rated only when means that the receiver experiencing worst network condition will conform to the sending rate. It has relatively low variation of throughput over time, which is suitable for applications that require a smooth sending rate like video streaming.The general working of TFMC congestion control as followsFirst step is the weighing of loss event rate and RTT by the receiver. By using this information with the help of TCP throughput equation the receiver derive a TCP friendly sending rate. In order to prevent feedback implosion at the sender the feedback is supplied only to a subset of the receivers using feedback suppression mechanism. In the receiver side the feedback is not suppressed and it calculates the transmission rate and gives it to the sender. This report has two main purposes, it helps to calculate the RTT for receiver and give the appropriate transmit rate for the sender.IV) TCP friendly congestion control for non-TCP applications.There are many studies conducted on TCP friendly congestion control for non TCP application. The congestion control mechanisms are used to achieve the following aimsUse of congestion control mechanisms help the applications to use the bandwidth more efficiently and thus increases the performanceThose applications which adjust to the network can easily make use of the wider bandwidth and more useful of the InternetCongestion Control algorithms helps to reduce the Congestive Collapse ie the situation in which network performs a little work referable to the over utilisation of network links.There are a minute of TCP friendly congestion control mechanisms are introduced now a days which include end-to-end schemes and hop-by-hop mechanism. The end- to- end mechanism consist of AIMD window based and rate based prot ocols and hop-by-hop consist of rate based hop-by-hop mechanism. The end-to-end congestion control mechanisms are necessary for responsive as well as unresponsive flows which reduce the traffic load when packet loss occurs. In rate based hop-by-hop congestion control scheme it matches the sending rate of the connection to the service rate observed at the downriver node.In window based AIMD schemes which utilises the increased and decreased congestion window of the sender. This mechanism has some advantage as well as some disadvantages. The major advantage is that it is familiar, reasonable in the field of fairness, stability, oscillations and other properties. The disadvantage is that it has more abrupt changes and oscillation in sending rate which is not suitable for real time streaming application.In rate based AIMD schemes, the most common examples are RAP (Rate Adaptation Protocol) and LDA (Loss-Delay based enrolment Algorithm). The LDA is mainly proposed for adapting the tran smission rate of multimedia applications to the congestion level of the network. It mainly relies on end-to-end Real Time transport Protocol (RTP) and its control protocol (RTCP) for feedback information. The major difference between rate adaptation schemes and window based schemes is that the latter is not ack-clocked. The main advantage is that the adaption of the sending rate deduces the no of oscillations and also helps to reduce the heavy traffic in real-time applications.