09-05-2012, 12:43 PM
Content Centric Network (CCN)
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Introduction
Content-centric networking is an innovative approach to networking that simplifies network use, improves performance and security, and enables a seamless, ubiquitous experience.Content-centric networks enable the content itself to migrate where it is needed. In an interconnected world where people access digital information via continually shifting modes – moving from location to location, using multiple mobile devices, connecting through diverse networks – a content-centric approach allows them to access relevant, self-organizing information without cumbersome plumbing (i.e., firewalls, VPNs, and ad hoc synchronization protocols). The network can meet specific information needs with available resources, operating within appropriate administrative, performance, and security constraints.
Working
The general proposal of content-centric networking recognizes that a great deal of information is produced once, and then copied many times. Therefore, it makes sense to distribute the copying and any related activities into the network's tree of equipment. In many cases, substantial storage is already available, and could be used more efficiently if it could recognize particular content and only keep one copy of it.
Since the network equipment is tree-shaped, it naturally scales content delivery to the size of the audience, and simultaneously reduces up-stream equipment to just the minimum needed to produce the content. As network service is built out, the content delivery naturally increases at the same time.
Structure of CCN Node
CCN communication is driven by the consumers of data. There are two CCN packet types, Interest and Data. A consumer asks for content by broadcasting its interest over all available connectivity. Any node hearing the interest and having data that satisfies it can respond with a Data packet. Data is transmitted only in response to an Interest and consumes that Interest.1 Since both Interest and Data identify the content being exchanged by name, multiple nodes interested in the same content can share transmissions over a broadcast medium using standard multicast suppression techniques. Data ‘satisfies’ an Interest if the Content Name in the Interest packet is a prefix of the Content Name in the Data packet. CCN names are opaque, binary objects composed of an (explicitly specified) number of components (see Figure 4). Names are typically hierarchical so this prefix match is equivalent to saying that the Data packet is in the name sub tree specified by the Interest packet (see Section 3.2). IP uses this convention to resolve the hnet;
Applications
Voice over CCN (VoCCN)
Content-oriented network architectures not only move content scalable and efficient. They can also implement IP-like conversational services like voice calls, email or transactions. To demonstrate this we have implemented and tested a Voice-over-CCN prototype. The result is functionally and performance equivalent to Voice-over-IP but substantially simpler in architecture, implementation and configuration.
Video & Audio Streaming
Despite the advent of ABR and HTTP streaming, there still is a need for live video delivery, since live video can't be cached like content that's previously recorded.
Online Gaming
Online games involve a large number of players and require a persistent world that is usually hosted by the game’s publisher thereby incurring a heavy load on the servers for player management and data transfer. Deploying such a game in a decentralized/P2P environment is not a straight forward task since it is difficult to obtain knowledge about the other players in the same sub-world and to efficiently disseminate the information to them. CCN can play a significant role here.
Virtualization
CCN can enable the next-generation of file virtualization devices that will automate the placement and movement of data between different storage tiers, with each tier potentially comprising devices from multiple vendors. CCN-based storage tiering can operate at the file chunk or object level (each file consisting of a number of objects) providing enterprises with fine-grained tiering flexibility. Depending on the application, organizations want to move files as well as objects within a file. This rapid, non-disruptive method of data migration can reduce downtime by as much as 90%.