Routing Economics Threaten the Internet
The Internet has some major problems. The big one involves the cost of supporting the amount of content and services being supplied over the Internet infrastructure. And if it’s not fixed soon, the expansion of Internet traffic could outrun our ability to pay for it.
Here’s why: Since it started, traffic on the Internet has about doubled every year. Remarkably, the router technology that we started with (best-effort packet routing) has supported this huge growth without any basic change except speed improvements resulting from the improvement in semiconductors.
Due to the improvements in fiber technology, the cost of increasing raw bandwidth capacity has been decreasing about as fast as the traffic grows. Fiber, therefore, is no longer the problem. But now that fiber technology has advanced, we have a different problem: routing technology. Internet traffic is now growing much more quickly than the rate at which router cost is decreasing per bit. Traffic is doubling each year, while routers follow the semiconductor trend, dropping in cost per bit by one half every 18 months.
The cost of Internet capacity would therefore double every three years without some key new innovation. The economy could not support this for very long.
Traditional routed IP networks provide reasonable quality by operating with huge overcapacity so the peak usage hardly ever overloads the routers. If a packet router becomes overloaded it seriously damages all the traffic, data, voice, and video. If we don’t find a way to keep up with these increasing capacity costs, we’ll start to see this damage.
I believe that the solution is flow routing. [Ed. note: Dr. Lawrence Roberts is the founder and CEO of Anagran Inc., a flow-based routing company.] Flow routing has introduced an important innovation that can help alleviate the capacity crunch: Routers do not need to route every packet, only the first packet in a flow. Thus, the inherent cost of these new routers is one third that of packet routers, and they provide an immediate 3:1 capacity increase when they are inserted into the network, eliminating the need to add capacity and cost for a year or two.
Flow router technology can be included at the access point where the overload may occur so that congestion and overload does not damage the traffic; lower priority, large file transfers are throttled back; and interactive voice and video stays protected. This allows the entire network to operate at much higher efficiency, often around 90 percent utilization day and night.
As the technology is further employed, the step function saving is on the order of 9:1 (cost and efficiency). This could extend the time that Internet traffic can continue to double at the current network cost by nine years. At that point, some additional innovation will be needed to keep cost under control or traffic growth will have to slow down.
The Internet’s problems are not limited to cost, however. The aging IP technology in the installed base has other challenges.
Quality: Today, video can be easily downloaded just like data, but streaming video only works well if the network has enough overcapacity, with data users kept on a separate network. In many cases (like WiFi, for example), the same is true for voice. We can’t even start to consider many other applications like “telesurgery” — robotic surgery performed remotely via the Internet — due to poor video quality as a result of packet loss and delay variance.
There are really two problems to solve here: controlling the huge network load caused by video downloading, and the inherent inability of the current packet router design to support low delay variance, with low-loss streaming media mixed with lots of data traffic. Flow routing could solve both these problems. Based on observing and remembering the state of each ongoing data stream (flow), the router can protect video, voice, and any real-time stream from delay variance and loss.
Security: Security is becoming a serious problem. Although it is partly a computer issue, in large part it is also a network issue, since current networking technologies do not verify who is sending the data. Most known security problems (denial of service, spam, viruses) would be much easier to cope with if the network included three additional functions: authorizing users as they connect to the network; checking the addresses a user claims to be sending from, to insure it is not faked; and detecting traffic anomalies such as denial-of-service attacks.
Authorization is a known technology, but not very useful without source address verification. Source address verification is expensive if required for every packet, but with the advent of flow routing, it can be done once per flow, making it extremely inexpensive. Similarly, detecting traffic anomalies is virtually impossible at the packet level, but quite reasonable with flow routing technology, by simply looking at the flow information. Thus, with the changes happening in routing technology, we should be able to pinpoint and identify anyone who sends spam or attacks a remote computer, and at least recognize and stop denial-of-service attacks, if not identify the originator. Once security attacks are traceable, law enforcement becomes possible.
Currently, we are expecting the same 40-year-old technology to support not only information exchange like Web browsing and email, but all our real-time traffic such as voice and video. Three basic problems must be overcome to accomplish this: quality, security, and economics. We need to improve packet forwarding design if we are going to fix these problems. — Dr. Lawrence G. Roberts, CEO, Anagran Inc.
http://www.internetevolution.com/author.asp?section_id=499&doc_id=136705&
http://slashdot.org/articles/07/10/25/1643248.shtml
