Internet Communications Using SIP : Delivering VoIP and Multimedia Services With Session Initiation Protocol {2Nd Ed.}

Figure 18.3 The decrease in average packet loss over the Internet over 10 years

Concerns Regarding Congestion Control

Not all regions in the world enjoy broadband Internet access, and in some
countries there is just not enough bandwidth to support acceptable VoIP. The
lack of bandwidth has actually led some Internet experts to be concerned
about the collapse of traffic if VoIP becomes more widespread in such band-
width-starved networks [11].
We have not seen, however, any reports of such congestion-based collapse,
and the proliferation of broadband and video in most parts of the world makes
any noticeable large-scale congestion collapse because of VoIP highly unlikely.

Internet Traffic Statistics: Voice Is Negligible

Several studies show that worldwide Internet traffic is dominated by P2P
applications, such as the file sharing of music and video. P2P traffic amounts
from 60 to 80 percent of traffic measured on the networks of several ISPs [12],
[13], as illustrated in Figure 18.5.

1000

100

10

1

0.1

0.01

0.001

Jan-95Jan-96Jan-97 Jan-98Jan-99 Jan-00Jan-01Jan-02 Jan-03Jan-04

100

10

1

0.1

Canada (19)

Japan (14)

S.E. Europe

China (13)

Latin America (37)

Expon. (ESnet (27))

Expon. (Europe (158))

Power (Edu/US (96))

% Monthly Median loss

Packet Loss Seen from ESnet

http://www.slac.stanford.edu/xorg/icfa/icfa-net-paper-jan05/

ESnet (27)

Europe (158)

50% improvement/yr

Russia

Edu/US (96)

Expon. (Canada (19))

Expon. (Japan (14))

Expon. (Edu/US (96))

0.01

Quality of Service for Real-Time Internet Communications 309