THE LARGER INTERNET II TECHNOLOGY ENVIRONMENT Fiber ...

144 CHAPTER 3 The Internet and World Wide Web
IP multicasting
a set of technologies that
enables efficient delivery of
data to many locations on
a network
diffserve
(differentiated quality
of service)
a new technology that
assigns levels of priority to
packets based on the type
of data being transmitted
make larger, more expensive software packages affordable for small businesses and
individuals.
BENEFITS OF INTERNET II TECHNOLOGIES
The increased bandwidth and expanded network connections of the Internet II era
will result in benefits beyond faster access and richer communications. Enhanced
reliability and quality of Internet transmissions will create new business models and
opportunities. Some of the major benefits of these technological advancements
include IP multicasting, latency solutions, guaranteed service levels, lower error
rates, and declining costs.
IP Multicasting. IP multicasting is a set of technologies that enables efficient delivery
of data to many locations on a network. Rather than making multiple copies of a
message intended to be distributed to multiple recipients at the point of origin of a
message, multicasting initially sends just one message and does not copy it to the
individual recipients until it reaches the closest common point on the network,
thereby minimizing the bandwidth consumed. (See Figure 3.17.) Network performance
is significantly improved because it isn’t bogged down with the processing and
transmission of several large data files; each receiving computer doesn’t have to query
the transmitting server for the file. Multicasting technologies are already making their
way into today’s Internet through the use of Mbone (a special-purpose backbone for
delivering video data).
Latency Solutions. One of the challenges of packet switching, where data is divided
into chunks and then sent separately to meet again at the destination, is that the
Internet does not differentiate between high-priority packets, such as video clips, and
those of lower priority, such as self-contained e-mail messages. Because the packets
cannot yet be simultaneously reassembled, the result is distorted audio and video
streams.
Internet II, however, holds the promise of diffserve, or differentiated quality of
service — a new technology that assigns levels of priority to packets based on the type
of data being transmitted. Videoconference packets, for example, which need to reach
their destination almost instantaneously, would receive much higher priority than
e-mail messages. In the end, the quality of video and audio will skyrocket without
undue stress on the network. Live and on-demand TV and video will be possible once
Internet II is completed.
Guaranteed Service Levels. In today’s Internet, there is no service-level guarantee
and no way to purchase the right to move data through the Internet at a fixed pace.
The Internet is democratic — it speeds or slows everyone’s traffic alike. With Internet
II, it will be possible to purchase the right to move data through the network at a guaranteed
speed in return for higher fees.