NPX Technology
Core Technology - Application Layer Routing

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The core function of an IP router is to transport an IP packet from a client to a destination based on the IP address. This means IP routers are unaware of what the packet contains, what applications are in use at either end of the connection. Their sole function is to forward traffic from Point A to Point B. Like the a transport system, they see only the freight or passengers to be hauled to a city, not which part of the city they really need to visit or what their final business may be.

As such, the IP router plays no role in the decision of which server is selected for a client, it only assists in transporting packets along a designated route.

Web switches perform application-level switching of connections from clients to servers, and provide load balancing and fail-over capability across a known cluster of web servers. However, Web Switches can only perform switching among the servers. Because they must sit in the data path these switches can themselves become bottlenecks or a point of failure and congestion.

Similarly, multisite web switches (sometimes called Global Directors) are often based on LAN-style web switches.

	Most such devices were designed for the LAN, resulting in an approach does not scale well, typically only supporting up to 20 sites.
	Many multi-site web switches are only “Site” aware (that is, they have only knowledge of the available sites, not the available servers) and route traffic based on network address information.
	As a result, these designs can only choose the closest site, the local web switch, and then the best server at the site. If all of the servers at that site are currently busy, then the client receives a slow response, even when there is a server available at an alternative location that could service the request.

Such products assist in the dynamic location and distribution of the content being requested. With cache hit rates averaging only in the 20 percentile and with the high cost of purchasing and maintaining fully replicated content servers, it is clear that choosing the best server is only part of the problem. Being able to do real-time global location and optimal distribution of content is also mandatory.

By contrast, the Adara NPX™ takes a different approach, creating and coordinating a globally distributed collection of all sites, servers, and content in the network.

	The NPX operates on object-based routing, provides global load balancing, fail-over capability, and content management.
	Using the NPX provides the means to dynamically direct or redirect clients to the optimal server, allowing the system to dynamically locate or re-locate objects on demand.
	The result is that needed objects can be brought to a point in the network where they can better service the request, as required.

Using the NPX’s Object Routing (known as GOLD - Generic Object Locator by Distance), the system builds tables that contain the best location for objects on the network. Oroute maintains this table, by exchanging object information with its neighbors, and is constantly aware of optimal routes and locations of objects in its tables. Unlike name-based routing, the NPX can provide host-based routing,

Moreover, the NPX can provide a single platform for additional network services and objects, be they static or dynamic, streaming files such as audio or video (stored or live), documents, files, applications and other web services.

Comparison: Web Switches and the Network Path Xcelerator
TRADITIONAL WEB SWITCHING ADARA NPX

Traditional web switching		Adara NPX
	In the data flow, with TCP splicing		Can be in or out of the data flow, no splicing
	Operate in isolation, over prescribed pathways, with single points of failure		Meshed topology with dynamic overlay for optimal routing over any path that is redundant and fault tolerant
	High overhead, requiring full state		Low overhead, with minimal state
	Scale from 2 – 20 nodes		Scale to thousands of locations
	Bind clients to sub-optimal sites		Constantly re-assesses to maintain optimality
	Local load balancing, with non- deterministic weighted avg/round robin/DNS rr/least connection methodology		Local and global load balancing with multiple optimization mechanisms including least congested path and server
	High latency with built-in bottlenecks		High performance with no bottlenecks
	Traffic flow with active discovery and DNS hierarchies; high hit rates requires full replication and non-scalable LDNS		Traffic management with predetermined redirection; replication on demand via push/ pull delivers high hit rate with minimal overhead
	Switches based upon Addresses: Carries ~100,000 entries		Routes based upon Objects: Carries Millions to Billions of entries
	Always hits origin server to perform redirection – no traffic localization		Directs to and draws content from any source; localizes traffic and minimizes origin hits
	No aggregation or peering; can multi- source content only from 2-20 nodes in hierarchy		Global aggregation and peering; can multi- source content from and to anywhere
	ASIC design		Extensible design
	Sit far from the edge with high latency		Sit anywhere in the network including the edge

XSA – Creating Server Cooperation

With the Adara NPX’s XSA (eXternal Server Adapter) capabilities, organizations can create a global cluster of heterogeneous servers distributed over the network, either within a co-location site or across the global net. Servers within the cluster are peered to share content and services with each other.

The result is a virtual server with the storage and computation capacity equivalent to the aggregate of all the individual servers.

	XSA acts as a gateway between heterogeneous servers and the virtual server network, to allow services to be shared among the server cloud.
	With XSA as a part of your network, the need to force unmodified servers to use the same protocol or interface used by other servers for information sharing is eliminated.
	Since XSA eliminates the barriers from heterogeneous environments the power of your servers is combined, both increasing overall capabilities of your servers and increasing the resilience of your network against downtime.

XSAs are service-specific adapters providing complete extensibility of the Adara Solution to any service, without customization and are not limited to any specific content. These solutions are available for any service through configuration; protocol adapters, in the form of modules, plug in and provide service without extensive re-engineering, system downtime, or performance and scalability drop-offs.

Quality of Service (QoS) Capabilities

While all organizations send data – generally a lot of it – over their networks and between locations, not all data is created equal. Some data, such as in-process transaction requests and streaming audio or video is more sensitive to delay than more static data, such as email or ftp requests. If time sensitive data is required to share resources with non-time sensitive traffic, an effective means for managing the resources so vital traffic is not delayed is essential.

Because the NPX-QoS™ capability is created for the entire network, not on a per-link basis, path control is established network-wide using the NPX Global Configurator, a easy-to-use graphical interface that allows QoS policies to be established with the desired parameters, then pushed to those NPX systems where the policies are to be established.

Network technology has two significant issues it must face:

	Applications with specific quality of service characteristics, most specifically bandwidth and delay, cannot generally reserve these qualities across all networks. Hence, where availability of bandwidth cannot be predicted in terms of quantity and quality (such as across the public Internet) there is a limitation to these applications.
	Where multiple applications are in use, it is often impossible to differentiate between traffic types. The result is that a user or application (or a set of users and applications) can often take control of all available bandwidth, preventing others from using the network.
	To provide control over these issues, effective Quality of Service (QoS) controls must be put into place to allocate available bandwidth to applications and users sharing a intranet or Internet link.

Within the Adara NPX is a core QoS capability that allows for application-based traffic prioritization based on provisioning rules to classify all traffic. Traffic passes through a set of filters designed to classify it as follows:

	Traffic type: TCP/IP or UDP ports or services (http, ftp, email, telnet, etc.) .
	Source address/destination address: To provide differentiation between traffic between different network systems or devices.
	Network, subnet source, or destination IP address: Allows separation between organization or based upon overall network topology.
	ToS (Type of Service) field: Designed to be used by the upper layers to provide information to the Internet layer to optimize the packet route, the ToS field is used in both routing and queuing algorithms.
	URL: Wildcards in the URL specification may be included.

These classification filters may be combined using hierarchies such that a specific QoS can be assigned to all traffic originating from and organization, then traffic within that organization can have a subset of the specified QoS reserved for a specific application, such as email or telnet traffic. What’s more important, all functions can be carried out from a single network control center, with policies pushed across the network to any NPX, or to defined sets of NPX systems. Policies can be established for indefinite periods, or a predetermined time span.

With the Adara NPX, traffic can be effectively managed, allowing mission critical applications to have optimal use of limited resources.

Network Security Functions

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Because network connections work in both directions, connection of corporate resources to a public network, such as the Internet, represent a potential risk to those resources and transport of data across such networks risks exposing private data to others.

To combat such exposure, networks are secured, using firewalls to provide a means to lock out unauthorized access and encryption to secure data being transmitted over the Internet from unauthorized users.

These network technologies already exist to provide security for networks. Yet many devices on the edge of the network remain with limited use of them because implementation is too costly to establish and administer.

With the NPX’s advanced technologies, secure, dynamic routing is achieved with extremely low encryption overhead, meaning that the data transmitted over the encrypted tunnels does not pay a severe penalty in the form of latency at the encryption point. The NPX provides the most scaleable secure tunneling, based on link state tunnels with no area 0 required.

Because the NPX provides Firewall, and IPSec or SSL based encryption, systems on the edge of the network can be used to provide that location with a comprehensive security feature set without the cost or administration of a set of additional devices. Instead, NPX systems can provide this function from the network edge to the center, without the need for local expertise or administrative overhead.