ABSTRACT
Internetworks come in a variety of topologies and levels of complexity — from single-protocol, point-to-point links connecting cross-town campuses, to highly meshed, large-scale wide area networks (WANs) traversing multiple time zones and international boundaries. The industry trend is toward increasingly complex environments, involving multiple media types, multiple protocols, and often interconnection to
unknown
networks. Unknown networks may be defined as a transit network belonging to an Internet service provider (ISP) or a telco that interconnects your private networks. In these unknown networks, you do not have control of such factors as delay, media types, or vendor hardware.
