1. Analysis of Delay and Jitter of Voice Traffic Over the Internet
Mansour J. Karam, Fouad A. Tobagi
IEEE INFOCOM 2001

2. The Queuing Model of Voice Traffic in a Packet Network
The queuing model of voice traffic in a packet network is or
M / D / 1

3. Voice Traffic Characteristics and Requirements
Maximum tolerable round-trip delay : ms
If packet loss were to occur, the number of contiguous packets which are lost is usually larger than one (clip).
Clips exceeding 60 ms affect the intelligibility of the received speech.

4. End-to-end Delay Components for Voice Traffic

5. Various Delay for G.711, G.729A and G.723.1

6. End-to-end Delay Expression
D : end-to-end delay
Tf : formation delay
l : lookahead
Th : transmission delay
Qh : queuing delay
Ph : propagation delay
Dplay : playout buffer delay

7. End-to-end Delay Expression (continued)
Assuming Qmax represents the maximum queuing delay percentile incurred in the network,

8. General Network Topology

9. Model for Queuing Delay in The Network

10. Voice Sharing the Link with Other Traffic
For a given hop,
:time interval before admittance.
:time interval after transmission.
: perturbation introduced by lower priority packets over the hop, ranged from 0 to Tp, uniformly distributed.

11. Voice Sharing the Link with Other Traffic (continued)
Distribution of : A triangular.
As N increasing, total perturbation
is normally distributed.
End-to-end inter-arrival time is also normally distributed with mean Tf and standard deviation

12. Voice Sharing the Link with Other Traffic (continued)

13. Number of Hops and Link Utilization

14. Number of Hops and Link Utilization (continued)

15. Available Bandwidth

16. Choice of Packetization Scheme

17. Choice of Packetization Scheme

18. Conclusion In this paper, the author verified:
Effect of the residual transmission time of non-voice delay
Importance of bandwidth to reduce the percentile
Effect of packet size on voice delay and bandwidth utilization