W. Jiang and H. Schulzrinne, "QoS measurement of Internet real-time multimedia services," tech. report CUCS-05-99m, Columbia Univ., New York, Dec. 1999.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....are then applied to the packet traces for quality assessment. Since IP telephony applications often use silence suppression to reduce their sending rate, we simulate talkspurt and silence periods within each voice call using for both periods an exponential distribution with an average of 1. 5s [13]. Packets belonging to a silence period are simply ignored. At the receiver end, we assume that a playout buffer is used to absorb the delay variations in the network. The playout delay is defined as the difference between the arrival and the playout time of the first packet of a talkspurt. ....

W. Jiang and H. Schulzrinne. Qos measurement of internet real-time multimedia services. Technical Report CUCS-015-99, Columbia University, December 1999.

....that is seen by RL agent RL d;ip , denoted by t d;ip;ft;k . These measurements are used to determine the state x d;ip;k . At a destination node, the measurements that are required are those related to the end to end QoS experienced by that ow such as end to end delay, throughput and loss [15]. End to end delay may be dicult to measure as it requires either a timestamp on each packet and clock synchronization between the source and the measurement probe, or a eld within the packet which accumulates the actual delay experienced at each node. These measurements will be compared against ....

W. Jiang and H. Schulzrinne, QoS Measurement of Internet Real-Time Multimedia Services, Technical Report CUCS-015-99, Dept of Comp. Sc., Columbia University, 1999.

....are then applied to the packet traces for quality assessment. Since IP telephony applications often use silence suppression to reduce their sending rate, we simulate talkspurt and silence periods within each voice call using for both periods an exponential distribution with an average of 1. 5s [15]. Packets belonging to a silence period are simply ignored. At the receiver end, we assume that a playout buffer is used to absorb the delay variations in the network. The playout delay is defined as the difference between the arrival and the playout time of the first packet of a talkspurt. ....

W. Jiang and H. Schulzrinne. Qos measurement of internet real-time multimedia services. Technical Report CUCS-015-99, Columbia University, December 1999.

....ffl low number of parameters states resulting in simple implementation and the opportunity of on line parameterization. ffl applicability to mechanisms which influence loss correlation (chapter 6) In [SC00a] we have introduced our model heuristically. Jiang and Schulzrinne then have shown in [JS00b] how our model can be derived from a general Markov model with simplifying assumptions. We adopt this approach in section 4.1.1 and present further evidence that the simplification, while reducing the model complexity, does not impair the significance of the derived metrics. Then, we introduce ....

....variable bitrate sources or silence detection (section 2.2.2) are employed that the loss indicator function only approximates the loss as a function of time (cf. section 1. 1) A general Markov model which describes the loss process using the loss indicator function is defined as follows ( YKT95, JS00b] Let P ( l(s) j l(s Gamma m) l(s Gamma 2) l(s Gamma 1) be the state transition probability of a general Markov model of order m. All combinations for the values (0 and 1) of the sequence l(s Gamma m) l(s Gamma 2) l(s Gamma 1) appear in the state space. As an example ....

W. Jiang and H. Schulzrinne. "QoS Measurement of Internet RealTime Multimedia Services". In Proceedings NOSSDAV, Chapel Hill, NC, June 2000.

....though generating a lot of interest in recent years, has not been successful. Schulzrinne et al. outline that the total end to end delay in a VoIP session comprises operating system delays, host hardware input output delays, possible look ahead delay, network delays and nally application delay [17]. Host delay includes packetisation delay which depends on the particular codec employed. Network delay includes the xed propagation delay, the transmission delay which is set by the interface speed and queueing delays at routers switches along the way. The application delay is introduced by the ....

Jiang, W., Schulzrinne, H., QoS Measurement of Internet Real-Time Multimedia Services.

....management algorithm which can be used for intra ow loss control. In section 5, we present results documenting the performance of the proposed mechanisms at both the end to end and hopby hop level. Section 6 concludes the paper. 2. METRICS 2. 1 Packet level metrics A general Markov model ([19, 6]) which describes the loss process is de ned as follows: Let P ( l(s) j l(s m) l(s 2) l(s 1) be the state transition probability of a general Markov model of order m, where l(s) is the loss indicator function for the packet with the sequence number s. All combinations for the values ....

W. Jiang and H. Schulzrinne. QoS measurement of Internet real-time multimedia services. In Proceedings NOSSDAV, Chapel Hill, NC, June 2000.

....gap is small (e.g. 30 ms) the bu er depth may not have changed much, then the next packet will also likely experience a high delay. We also compute the queueing delay distribution in some approximated queueing models. Figure 6 shows the conditional CDF for an M=D=1 system with di erent lags [11]. lag=3 lag=5 lag=10 lag=20 unconditional lag=2 lag=1 0 0.2 0.4 0.6 0.8 1 0 5 10 15 20 25 30 delay (sec) Figure 6: CCDF of M=D=1 system, 1 3 ; 1 2 The temporal dependency of delay has a strong implication on the quality of real time multimedia services. When a packet s ....

Wenyu Jiang and Henning Schulzrinne. Qos measurement of internet real-time multimedia services. Technical Report CUCS-015-99, Columbia University, New York, New York, December 1999.

No context found.

W. Jiang and H. Schulzrinne, "QoS measurement of Internet real-time multimedia services," tech. report CUCS-05-99m, Columbia Univ., New York, Dec. 1999.

No context found.

Jiang W, Schulzrinne H. QoS measurement of Internet real-time multimedia services. In Proceedings of NOSSDAV, Chapel Hill, NC, June 2000.

No context found.

W. Jiang and H. Schulzrinne, "QoS measurement of internet real-time multimedia services," in Proc. NOSSDAV, Chapel Hill, NC, June 2000.

No context found.

W. Jiang and H. Schulzrinne, "Qos measurement of internet real-time multimedia services," in Proceedings NOSSDAV 2000.

No context found.

Jiang, W. and H. Schulzrinne: 1999, `QoS measurement of Internet real-time multimedia services'. Technical Report CUCS-015-99, Department of Computer Science, Columbia University.

No context found.

W. Jiang and H. Schulzrinne, "Qos measurement of internet real-time multimedia services," in Proceedings NOSSDAV 2000.

No context found.

W. Jiang and H. Schulzrinne. Qos measurement of internet real-time multimedia services. Technical Report CUCS-015-99, Columbia University, December 1999.

No context found.

W. Jiang and H. Schulzrinne, "QoS measurement of Internet real-time multimedia services," Proceedings NOSSDAV, Chapel Hill, NC, June 2000.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC