{{unreferenced, date=February 2013
Content processors are sometimes confused with network processors that inspect the
packet
Packet may refer to:
* A small container or pouch
** Packet (container), a small single use container
** Cigarette packet
** Sugar packet
* Network packet, a formatted unit of data carried by a packet-mode computer network
* Packet radio, a form ...
computer network
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ...
. These components allow for the design and deployment of next-generation networking systems that can make packet or message processing decisions based on an awareness of the packet or message content. The work of Content Processors is often termed Content Processing or
Deep Packet Inspection
Deep packet inspection (DPI) is a type of data processing that inspects in detail the data being sent over a computer network, and may take actions such as alerting, blocking, re-routing, or logging it accordingly. Deep packet inspection is oft ...
, DPI, though some people feel that the expression DPI is too limiting as many Content Processors can modify and re-write content on the fly - therefore they can do much more than just inspect which implies a sort of monitoring only function.
Unlike knowledge based processors or Ternary
Content-addressable memory
Content-addressable memory (CAM) is a special type of computer memory used in certain very-high-speed searching applications. It is also known as associative memory or associative storage and compares input search data against a table of stored d ...
(TCAMS), which mainly target the packet header (twenty percent of the packet currently comprises the header), content processors go much further into the packet or message thereby determining the nature of the content in the packet itself (80% of the packet currently is data).
Applications of content processors include: layer 7 application, application-oriented networks
switches
In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type of ...
computer appliances
A computer appliance is a home appliance with software or firmware that is specifically designed to provide a specific computing resource. Such devices became known as ''appliances'' because of the similarity in role or management to a home a ...
,
Intrusion Detection
An intrusion detection system (IDS; also intrusion prevention system or IPS) is a device or software application that monitors a network or systems for malicious activity or policy violations. Any intrusion activity or violation is typically rep ...
, prevention systems (IDS/IPS),
anti-virus
Antivirus software (abbreviated to AV software), also known as anti-malware, is a computer program used to prevent, detect, and remove malware.
Antivirus software was originally developed to detect and remove computer viruses, hence the name. ...
XML
Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable ...
gateways. The various layers of the
OSI model
The Open Systems Interconnection model (OSI model) is a conceptual model that 'provides a common basis for the coordination of SOstandards development for the purpose of systems interconnection'. In the OSI reference model, the communications ...
are given in the link that follows with a description of layer 7 where content processing is and will become and integral part of the intelligent network as the next generation networks mature.
Advanced Content Processors can both examine and transform content. For example: Microsoft's new Office 2007 product has the ability to save documents in an open
XML
Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable ...
format, instead of .ppt, .xls and .doc applications will save to an encapsulated (actually ZIP) file type named .pptx, .xlsx and .docx. So a content processor could be used to examine all of a corporations documents and replace one company name with another, or change an included corporate logo - all because the structured data represented in XML can be manipulated much more easily than a proprietary and undocumented format. XML is often described as a self-describing language.
Some Content Processors support the ability to handle both message-based or packet-by-packet analysis and some can keep track of content across multiple packets so that the signatures they may be searching for can cross packet boundaries and they will still be found.