Adaptive Private Networking (APN) is an upcoming and innovative way to establish WAN links.

Traditionally, Frame Relay, ATM and MPLS based WAN services have been prevalent owing to higher levels of reliability (high availability; and lower packet loss, latency and jitter) offered by those technologies. All along, these traditional WAN services have remained expensive commodities for enterprise. Although the cost of high speed internet connections has decreased rapidly over the years, but same cost reduction has not been seen in private WAN services.

 

Adaptive Private Networking (APN) is based on packet-by-packet, real-time traffic engineering that leverages the reliability and bandwidth of multiple inexpensive active paths through the Internet. Key here is "leveraging multiple inexpensive active paths" to intelligently exploit the superior price/performance of consumer-oriented ISP services. APNs affords higher levels of reliability, dramatic cost savings alongwith significantly more bandwidth as opposed to traditional WAN services.

 

When rightly employed APN offers approximately 30-100 times more bandwidth per dollar as compared to traditional WAN services, resultant a reduction of 40-80% in WAN expenses. Previous advantage comes coupled with functionality of end-to-end QoS and higher reliability than traditional ATM, FR or MPLS services.   

 

Internet VPNs employing IPSec routers over low cost internet access services can be an attractive economic alternative to traditional WAN services. However, public internet and consumer-class ISP services have issues of QoS and reliability, due to which Internet VPNs are not ideally suited as primary enterprise WAN links.

 

APN is based on the concept of adding intelligence to a multitude of consumer grade network connections and hence creating a low cost, highly reliable enterprise class service. Basic concept is similar to RAID (Redundant Array of Inexpensive Disks) arrays, creating highly reliable enterprise grade storage by wrapping a layer of intelligence around cost effective consumer grade hard disk drives.

 

APN requires that special appliances be placed physically or logically in-line with the internet access routers at every site that participates in APN. As shown, both the central location and branch location sites access the internet via two ISPs each. As a result there are four different paths between the pair of sites over the internet. It is also possible to have a fifth path between the two sites using a traditional WAN service. The appliance encrypts and encapsulate each packet traversing the internet. Encryption is optional for packets sent over existing private WAN connections. The encapsulation header includes a time stamp, 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.

 

 

APN devices use combination of capabilities like real-time performance monitoring, application awareness, multipath connectivity, adaptive path selection and network fabric optimization to make multiple parallel network path function as a single high bandwidth connection with predictable application performance; affording high availability and low packet loss, latency and jitter.

 

WAN Optimization products referred as WOCs or WAN Optimization Controllers are often mixed/confused with APN; WOCs are focused on improving the cost and performance of delivering applications from centralized data centers to branch office employees over WAN links like ATM, FR and MPLS. WAN Optimization techniques are employed, firstly to reduce the amount of data that must be transmitted over a WAN and secondly; to mitigate the impact of inefficient protocols and applications.