Today, the moniker has been attached to Chiappa's vision of a next-generation architecture for Internet routing and addressing.

Few know about Nimrod because the architecture has not yet been turned into technology. BBN Systems and Technology, under a grant from the Advanced Research Projects Agency, is responsible for making that happen--as a public domain offering--by early next year, says Martha Steenstrup, BBN's technical lead.

However, even at this early stage, Nimrod is making waves. The ATM Forum, for example, borrowed heavily from Nimrod in designing its resource-sensitive Interim Inter-Switch Signaling Protocol. One of Nimrod's primary goals is to prevent an Internet routing meltdown--a disaster that is becoming increasingly possible as routing paths multiply. Nimrod also promises to let users choose the path traffic takes across the Internet, based on provider preferences such as pricing, reliability, reputation and application bandwidth requirements. Chrysler Corp.'s Bob Moskowitz believes Nimrod is "more critical than the majority of people realize" because with 23,000 of 30,000 routes already in use, Internet routing could break down in just a year.

Nimrod adds a layer of abstraction into routing, so that services and physical entities--such as a community of hosts, routers and networks that comprise a corporate site--can be viewed as a single Nimrod node. Each Nimrod node has one or more "maps" that describe the packet transport services it provides and its connectivity to adjacent nodes. The approach streamlines global routing information and lets managers opt for greater privacy by walling off network detail behind a node.

Nimrod relies on several new protocols and databases. It also opens a path for route server functions to be performed for multiple companies by a service provider or a separate on-site device. The architecture is slated to support multicast capabilities and mobile communications, too. Since Internet payment structures are still uncertain, Nimrod includes "place holders" for implementing route generation algorithms that work with various charging schemes. Nimrod can be incrementally deployed as an island or across IPv4, IPv6 or OSI, using encapsulation.

Here's how packets are routed using Nimrod: A host seeks the address of a destination by transmitting a Domain Name System query. The Nimrod router intercepts the DNS response and determines if it has a route available. If not, it obtains one from a Nimrod route server. The router then forwards packets to the destination by attaching the route to each packet or establishing forward state in Nimrod routers along the route (for longer sessions). Forward state means that information about a specific path is encoded in the packet.

What's Nimrod's downside? It is untested technology. There are also those who fervently believe that the Internet has flourished because it has evolved, taking one baby-step at a time. Why risk rearchitecting the thing now? One thing is for certain, we won't even begin to get an idea of Nimrod's true potential until technology trials begin this fall. For more information on Nimrod, FTP ds.internic.net.

Christine Hudgins-Bonafield can be reached at cbonafield@nwc.com. You can also e-mail Christine directly . .