IPv6, 2nd Edition

Chapter 4 • The Road to Next Generation 61

itself with some qualification. What might be called ad hoc inter-

networking—where one organization provided connectivity to

one or more other organizations or individuals by routing

those others’ packets—was common in the early days of

the Internet. However, by the mid-1990s backbone-oriented

routing—where global Internet connectivity is offered to con-

sumers, whether individuals, organizations, or government

agencies—became the dominant model.

• The Internet must be able to interconnect as many as one bil-

lion (10

9

) networks, although the consensus seemed to encom-

pass a relatively broad range of anywhere ...