Network Search Engine
Encyclopedia
Computer network
s are connected together to form larger networks such as campus networks, corporate networks, or the Internet
. Routers are network devices that may be used to connect these networks (e.g., a home network
connected to the network of an Internet service provider
). When a router interconnects many networks or handles much network traffic, it may become a bottleneck and cause network congestion (i.e., traffic loss).
A number of techniques have been developed to prevent such problems. One of them is the Network Search Engine (NSE), also known as Network Search Element. This special-purpose device helps a router perform one of its core and repeated functions very fast: address lookup
. Besides routing
, NSE-based address lookup is also used to keep track of network service usage for billing purposes, or to look up patterns of information in the data passing through the network for security reasons.
Network Search Engines are often available as ASIC chips
to be interfaced
with the network processor
of the router. Content-addressable memory
and Trie
are two techniques commonly used when implementing NSEs.
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
s are connected together to form larger networks such as campus networks, corporate networks, or the Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
. Routers are network devices that may be used to connect these networks (e.g., a home network
Home network
A home network or home area network is a residential local area network . It is used for communication between digital devices typically deployed in the home, usually a small number of personal computers and accessories, such as printers and mobile computing devices...
connected to the network of an Internet service provider
Internet service provider
An Internet service provider is a company that provides access to the Internet. Access ISPs directly connect customers to the Internet using copper wires, wireless or fiber-optic connections. Hosting ISPs lease server space for smaller businesses and host other people servers...
). When a router interconnects many networks or handles much network traffic, it may become a bottleneck and cause network congestion (i.e., traffic loss).
A number of techniques have been developed to prevent such problems. One of them is the Network Search Engine (NSE), also known as Network Search Element. This special-purpose device helps a router perform one of its core and repeated functions very fast: address lookup
Lookup
In computing, lookup usually refers to searching a data structure for an item that satisfies some specified property. For example, variable lookup performed by a language interpreter, virtual machine or other similar engine usually consists of performing certain...
. Besides routing
Routing
Routing is the process of selecting paths in a network along which to send network traffic. Routing is performed for many kinds of networks, including the telephone network , electronic data networks , and transportation networks...
, NSE-based address lookup is also used to keep track of network service usage for billing purposes, or to look up patterns of information in the data passing through the network for security reasons.
Network Search Engines are often available as ASIC chips
Application-specific integrated circuit
An application-specific integrated circuit is an integrated circuit customized for a particular use, rather than intended for general-purpose use. For example, a chip designed solely to run a cell phone is an ASIC...
to be interfaced
Look-Aside Interface
The Look-Aside Interface is a computer interface that was specified by an interface interoperability agreement produced by the Network Processing Forum. It specifies the method to interface a Network Processing Element to a Network Search Element...
with the network processor
Network processor
A network processor is an integrated circuit which has a feature set specifically targeted at the networking application domain.Network processors are typically software programmable devices and would have generic characteristics similar to general purpose central processing units that are commonly...
of the router. Content-addressable memory
Content-addressable memory
Content-addressable memory is a special type of computer memory used in certain very high speed searching applications. It is also known as associative memory, associative storage, or associative array, although the last term is more often used for a programming data structure...
and Trie
Trie
In computer science, a trie, or prefix tree, is an ordered tree data structure that is used to store an associative array where the keys are usually strings. Unlike a binary search tree, no node in the tree stores the key associated with that node; instead, its position in the tree defines the...
are two techniques commonly used when implementing NSEs.