Adaptive Private Networking

Insightful analysis by consultants Steve Taylor and Jim Metzler, plus links to the latest WAN news headlines

The last two newsletters have highlighted the relatively high cost of wide area networking and identified a technique to add intelligence to a multitude of consumer grade products or services and hence create a low cost, highly reliable enterprise class product or service. This newsletter will discuss a breakthrough network technology that builds on that concept in order to drastically lower the cost of wide area networking.

The technology is referred to as Adaptive Private Networking (APN). Just as RAID creates enterprise class storage by wrapping a layer of intelligence around high volume consumer grade hard disk drives, APN creates an enterprise class network by wrapping a layer of intelligence around IPSec VPNs that are accessed using cable and/or xDSL.

APN requires that appliances be placed in-line with the Internet access routers at every site that participates in the APN. Assume that both the enterprise data center and the remote office sites access the Internet via two ISPs. This means that there are four parallel paths between the pair of sites. The APN appliances encrypt and encapsulate each packet traversing the Internet. The encapsulation header includes a timestamp, sequence number and an IP address of the destination APN appliance that corresponds to the far end ISP that will be used by this particular packet.

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The last two newsletters have highlighted the relatively high cost of wide area networking and identified a technique to add intelligence to a multitude of consumer grade products or services and hence create a low cost, highly reliable enterprise class product or service. This newsletter will discuss a breakthrough network technology that builds on that concept in order to drastically lower the cost of wide area networking.

The technology is referred to as Adaptive Private Networking (APN). Just as RAID creates enterprise class storage by wrapping a layer of intelligence around high volume consumer grade hard disk drives, APN creates an enterprise class network by wrapping a layer of intelligence around IPSec VPNs that are accessed using cable and/or xDSL.

APN requires that appliances be placed in-line with the Internet access routers at every site that participates in the APN. Assume that both the enterprise data center and the remote office sites access the Internet via two ISPs. This means that there are four parallel paths between the pair of sites. The APN appliances encrypt and encapsulate each packet traversing the Internet. The encapsulation header includes a timestamp, sequence number and an IP address of the destination APN appliance that corresponds to the far end ISP that will be used by this particular packet.

Part of the intelligence layer provided by an APN is the ability to do real-time performance monitoring. In particular, the APN appliances continually monitor each of the parallel network paths on a packet-by-packet basis for loss, latency and jitter.

Another part of the intelligence layer provided by an APN is adaptive path selection. Adaptive path selection algorithms are employed to make instantaneous selections of the best path for each application type on a packet-by-packet basis. If there is a failure or congestion in one of the paths, traffic can be re-directed in as little as a few hundred milliseconds. Application-aware adaptive path selection among multiple paths provides a form of virtual QoS for the public Internet. The path selection algorithms also provide load distribution across all paths to ensure that the maximum advantage is taken of all the available bandwidth.

The next newsletter will focus on the cost savings that are associated with APN. In the mean time, more information on APN can be found here. In addition, Jim will be moderating a session at the November Interop conference in NYC on the topic of breakthrough network technologies. APN is just one of five technologies that will be discussed by the panelists. If you plan to attend Interop, you might want to make sure you attend that session.

Read more about lans & wans in Network World's LANs & WANs section.

Steve Taylor is president of Distributed Networking Associates and publisher/editor-in-chief of Webtorials. Jim Metzler is vice president of Ashton, Metzler & Associates.