Internet traffic comes in many flavors. At any given time, there are packets traversing the globe carrying electronic mail, Web content, real-time audio, and other network services. Currently, all of these packets are given the same priority, and usually take about the same length of time to travel between the same two points on the Net.
MCI and Cisco Systems are working together to change this. Nearly a year ago, Cisco announced NetFlow, a software upgrade that added a number of new features to its 7000 series of routers.
Among these is support for the Resource Reservation Protocol (RSVP), which allows a user to reserve bandwidth for future use, and know that it will be available when it is needed. MCI has now announced that it is going to support NetFlow and RSVP on its Internet backbone. This goes a long way toward eliminating network lag for real-time applications.
For example, a user in New York needs to hold a videoconference with his boss in Billings, Montana. Before the videoconference begins, the user can essentially tell the network that he will be needing a certain amount of guaranteed bandwidth. From that point forward, his videoconference packets will be given priority over other traffic flowing over the same wires into the same routers (as long as the routers support RSVP). There should be no network lag and his conference with his boss will go smoothly.
MCI is the first backbone provider to announce the upgrade of all of its routers to support RSVP. Fred Briggs, MCI's chief engineering officer, is quite proud of this. "MCI will be the first in the industry to offer multiple classes of services based on the customer's individual requirements," Briggs explains.
Those who watch the MCI bottom line are optimistic as well. MCI believes that guaranteed bandwidth is important enough to many of its customers that they will be charging a premium for the service. MCI spokeswoman Leslie Aun said the exact rates have not yet been determined. The other major network providers (nearly all of whom use Cisco hardware) are expected to follow suit.
RSVP is an indicator of the shape of things to come. Bandwidth reservation and packet prioritization are two very important aspects of IPv6, the next generation of Internet protocol.
IPv6 will not only support RSVP, but will also allow for the assignment of a priority to individual packets. This will allow packets that contain real-time data to traverse the network faster than those that are less time-critical, even if bandwidth hasn't been reserved.
For example, a user won't notice if a packet containing part of a piece of electronic mail takes 15 seconds to get from Tijuana, Mexico, to Key West, Florida, so a router can delay the forwarding of that packet if the network is crowded. If that packet contained streaming audio data, a 15-second end-to-end time would be unacceptable, and the router should forward it immediately. IPv6 will make routers intelligent enough to do exactly this.
Although IPv6 is working today on research networks like the 6bone, it will be some time before it is ready for general deployment. Until then, expect alternatives, like NetFlow, to step in and provide some of the desperately needed functionality of IPv6.
