Assessing the quality of voice communications over internet backbones

Markopoulou, Athina; Tobagi, Fouad A.; Karam, Mansour J.

doi:10.1109/tnet.2003.818179

Cited by 155 publications

(81 citation statements)

References 27 publications

(38 reference statements)

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“…[4], are similar to those of our work. However, they are focusing on the Internet Backbone between 5 cities and thus do not include the user access network.…”

Section: Related Worksupporting

confidence: 91%

Voice Quality on the Internet in 2005 as Measured by www.TestYourVoIP.com

Sylor¹,

Venna²,

Ripps³

2006

Lecture Notes in Computer Science

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Abstract. How well can the Internet serve as a network carrying voice calls? To answer that question, we have been running a web site called TestYourVoIP where users can run tests of VoIP Quality from their PC. In this paper we describe how TestYourVoIP operates, the kinds of tests it performs, and the results we have found from those tests. Our findings indicate that while many users will get acceptable call quality, too many will not. We offer some insights as to the reasons for poor quality based on these real world experiences. Lastly, we note that over 2005, voice quality on the Internet has gotten worse.

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“…[4], are similar to those of our work. However, they are focusing on the Internet Backbone between 5 cities and thus do not include the user access network.…”

Section: Related Worksupporting

confidence: 91%

Voice Quality on the Internet in 2005 as Measured by www.TestYourVoIP.com

Sylor¹,

Venna²,

Ripps³

2006

Lecture Notes in Computer Science

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“…We model the traffic of a VoIP connection in the talk burst fashion from [11]. Each VoIP connection is modelled as a 64 kb/s on-off packet stream where the on and off periods are exponentially distributed with a mean of 1.5 seconds.…”

Section: Voip Trafficmentioning

confidence: 99%

“…In [11], it is suggested that "mouth to ear" delay should be restricted to less then 100 ms, and so delivering a VoIP packet burst at every PLC frame interval will accommodate this (e.g. one packet every 40 ms).…”

Section: Voip Trafficmentioning

confidence: 99%

Dynamics of contention free period reservation in IEEE 1901 networks

Zarikoff

Malone

2012

2012 IEEE International Symposium on Power Line Communications and Its Applications

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Abstract-Power line communications (PLC) technology has become a competitor in the home networking arena. In an internetworked home, PLC promises to provide an inexpensive, high throughput, and easy-to-install means of extending connectivity to areas of the home or small office that have poor wireless coverage. A key enabling technology within the IEEE 1901 PLC standard is that of the contention free period (CFP). Following a successful reservation, a station allocated to the CFP will not suffer any form of contention-based packet loss. The IEEE 1901 standard presents this as a way of accommodating flows with well defined delay, jitter and bandwidth requirements. However, to date there has been little research done on the dynamics of the CFP reservation procedure and its scalability. Since the procedure inherently relies on the collision-prone contention access period for reservations, a successful reservation bid is not guaranteed on the first attempt. Our work looks at the resulting delay characteristics of the IEEE 1901 reservation procedure. We present details for 1-persistent and VoIP traffic.

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“…We consider a VoIP call as useful only if 95% of the packets sent in both directions are delivered within the delay bound. We use these constraints to model the QoS requirements of VoIP calls [23]. The simulation results have been averaged over 10 runs.…”

Section: Simulation Setupmentioning

confidence: 99%

Sticky CSMA/CA: Implicit synchronization and real-time QoS in mesh networks

et al. 2007

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We propose a novel approach to QoS for real-time traffic over wireless mesh networks, in which application layer characteristics are exploited or shaped in the design of medium access control. Specifically, we consider the problem of efficiently supporting a mix of Voice over IP (VoIP) and delay-insensitive traffic, assuming a narrowband physical layer with CSMA/CA capabilities. The VoIP call carrying capacity of wireless mesh networks based on classical CSMA/CA (e.g., the IEEE 802.11 standard) is low compared to the raw available bandwidth, due to lack of bandwidth and delay guarantees. Time Division Multiplexing (TDM) could potentially provide such guarantees, but it requires fine-grained network-wide synchronization and scheduling, which are difficult to implement. In this paper, we introduce Sticky CSMA/CA, a new medium access mechanism that provides TDM-like performance to real-time flows without requiring explicit synchronization. We exploit the natural periodicity of VoIP flows to obtain implicit synchronization and multiplexing gains. Nodes monitor the medium using the standard CSMA/CA mechanism, except that they remember the recent history of activity in the medium. A newly arriving VoIP flow uses this information to grab the medium at the first available opportunity, and then sticks to a periodic schedule, providing delay and bandwidth guarantees. Delay-insensitive traffic fills the gaps left by the real-time flows using novel contention mechanisms to ensure efficient use of the leftover bandwidth. Large gains over IEEE 802.11 networks are demonstrated in terms of increased voice call carrying capacity (more than 100% in some cases). We briefly discuss extensions of these ideas to a broader class of real-time applications, in which artificially imposing periodicity (or some other form of regularity) at the application layer can lead to significant enhancements of QoS due to improved medium access.

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Assessing the quality of voice communications over internet backbones

Cited by 155 publications

References 27 publications

Voice Quality on the Internet in 2005 as Measured by www.TestYourVoIP.com

Voice Quality on the Internet in 2005 as Measured by www.TestYourVoIP.com

Dynamics of contention free period reservation in IEEE 1901 networks

Sticky CSMA/CA: Implicit synchronization and real-time QoS in mesh networks

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