Vertical Services Integration Enabled Content Distribution Mechanism

Abstract

The invention relates to an enhanced ADSL Data Network (ADN) with vertical services capabilities. In general, vertical services capabilities are data services offered directly from a central office to an end user, without compromising the integrity of the user's guaranteed bit rate to the Internet through the ADN. One such vertical service is content downloadable at a high data rate from a content server located in or proximate to a central office that serves the end user. The content of the local server is updated and upgraded periodically and systematically from a central content server that distributes content to a number of remote central offices. The content is distributed between the central content server and the respective local content servers using available bandwidth, that is to say bandwidth on at least certain network links that is unused by subscriber traffic.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a continuation-in-part of application Ser. No. 09 / 635,695, entitled SUPPORT FOR QUALITY OF SERVICE AND VERTICAL SERVICES IN DIGITAL SUBSCRIBER LINE DOMAIN, filed Aug. 10, 2000.FIELD OF THE INVENTION [0002] Certain concepts involved in the present invention relate to techniques for implementing data communication services, for example in a local access network utilizing digital subscriber line technology, to support quality of service (QoS) and local introduction of vertical services. Other concepts involved in the present invention relate to distribution of content from a hub site to a server located at a central office through such a network. BACKGROUND [0003] Modern society continues to create exponentially increasing demands for digital information and the communication of such information between data devices. Local area networks use a network, cable or other media to link stations on the network for exchange of i...

AI Technical Summary

Benefits of technology

[0036] Another objective of the invention relates to improvement of the cost effectiveness of the data network, for example, by reducing the demand for high-capacity interoffice links while increasing the bandwidth available at the network edge for at least some types of services.

[0037] A related objective is to provide a technique for introduction of new high-end services near the network edge, such as content distribution, from a domain that is more secure and therefore less subject to hacker attacks.

[0042] The vertical services domain also represents a communication network. The vertical services domain, however, preferably takes the form of a data network optimized for local transport of vertically injected services, that is to say local data traffic. In view of its local nature, it is easier and more cost effective to provide high bandwidth services, such as content distribution to customers, from the local domain. The vertical services network, for example, could take the form of a giga-bit Ethernet type local area network. Also, it is easier to adapt the vertical services network to support service level agreements with customers with regard to quality of service. In many cases, it actually is sufficient to support QoS on the one hop through the ATM switch, itself.

[0044] Each of the remote central offices may house another switch, with vertical services insertion capabilities, and local content servers in communication with the vertical services insertion switch. The content is distributed, such that the distribution of content does not interfere with subscriber traffic between the hub site and the respective switches at the respective central offices. This is accomplished by utilization of otherwise unused bandwidth between the hub site and remote central offices during time periods when subscriber traffic does not utilize the entirety of this bandwidth. Once the content is distributed and stored on the local content servers at the remote central offices, the end users served by each central office can access content at a high speed from the nearest vertical services domain, without compromising the bandwidth allocated for Internet traffic or other traffic between the hub site and the respective remote central office.

Problems solved by technology

However, the common local area network architectures require installation of specialized wiring and use of specific wiring topologies.

High speed links enabling such wide area access from a LAN domain, for example using T1 lines, are quite expensive and justified only for hi-end commercial users.

The current design goals of DSL data networks for Internet access do not support high-end vertical services, that is to say services demanding IP-based applications that require assurance of some level of quality of service (QoS).

Streaming video has similar requirements, and in addition, requires high bandwidth.

For example, current implementations supporting ATM cell traffic employ the Unspecified Bit Rate (UBR) class of service, which does not provide any bandwidth or delay guarantees.

Consequently, transport of video materials through such DSL data networks inflicts video delays, loss of audio / video synchronization, and image fragmentation.

Furthermore, lengthy bandwidth intensive sessions for video or other broadband applications may degrade the throughput to all other subscribers served through a shared node, such as a gateway router or a concentrated link.

For two-way video, upstream will have even worse quality and throughput problems, due to the best effort nature of the DSL data network implemented for Internet access and because the upstream bandwidth is significantly less than that of the downstream channel.

In practice, this is a relatively long or wide area link using expensive interoffice facilities.

Although it was originally envisioned that ATM would support switched logical channels or virtual circuits, to date, such logical switching has proven impractical to implement and administer.

The virtual circuits to the ISPs, however, do not have sufficient capacity to simultaneously carry all subscriber traffic at the maximum rates of the customers' subscriptions.

The maximum grade of service offered to an individual subscriber depends on the rates for which the subscriber's line can qualify, although the subscriber may opt for a lower rate service since the higher-rate service is more expensive.

Voice telephone communication over IP is extremely sensitive to latency and jitter.

The permanent virtual circuits provide an unspecified bit rate (UBR) service and do not guarantee any minimal amount of delay or jitter.

Also, because the rates are set by subscription, the service tends to be relatively inflexible.

Such a migration strategy to implement new services creates severe problems.

If the rate of the requested video exceeds the customer's subscription rate, the customer could not view the video in real time during the download.

Even if the rate of the requested video is below the customer's subscription rate, loading in the Internet or the local access network may impose delays and / or jitter in communication of some segments of the requested video.

It might be possible to increase the capacity of the links 119 and / or the hubs 121; however, this tends to increase the carrier's recurring costs and often makes the overall service(s) of the ADN network economically impractical.

Administration and provisioning of one virtual circuit per subscriber is already complicated, and the number of virtual circuits through any given ATM node is limited by current equipment designs.

Expanding the number of permanent virtual circuits per subscriber to support multiple QoS tiers of service therefore would be quite expensive, and the management thereof would become a nightmare.

In point of fact, few nodes on the public Internet actually support any type of QoS.

Hence, even if the ADN supported a desired QoS, most subscribers would not benefit from that service because their communications over the public Internet would have no QoS guarantee, and would suffer from the usual problems of latency and jitter.

Consequently, current deployments of ADSL-based data networks, such as shown in FIGS. 8 and 9 generate many customer complaints.

From the customer perspective, the service does not deliver the data rates that the customer pays for on a consistent basis.

The customer typically blames such problems on network equipment failure.

In fact, most of the problems already are due to virtual circuit congestion problems, of the kinds outlined above.

Essentially, the ADN network is crippled by the unpredictable nature of the service levels that the customers perceive due to congestion on the ADN and on the public Internet.

Also, with this approach, because all of the major service elements are implemented in servers accessible to the Internet, all of the services are subject to severe security risks.

However, a consequence is that any such server is accessible to and thus subject to attack from any hacker having Internet communications capabilities.

Popular services, particularly those generating substantial revenues, become prime targets for attack.

Another area of problems is that the ADN does not offer the carrier any technique for offering its own differentiated service applications.

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