Network resources allocated for particular application traffic are aware of the characteristics of L4+ content to be transmitted. One embodiment of the invention realizes network resource allocation in terms of three intelligent modules, gateway, provisioning and classification. A gateway module exerts network control functions in response to application requests for network resources. The network control functions include traffic path setup, bandwidth allocation and so on. Characteristics of the content are also specified in the received application network resource requests. Under the request of the gateway module, a provisioning module allocates network resources such as bandwidth in optical networks and edge devices as well. An optical network resource allocation leads to a provisioning optical route. Under the request of the gateway module, a classification module differentiates applications traffic according to content specifications, and thus creates and applies content-aware rule data for edge devices to forward content-specified traffic towards respective provisioning optical routes.
BACKGROUND OF THE INVENTION
The present invention relates to content-aware dynamic network resource allocation in a network such as the Internet and in one embodiment to content-aware dynamic optical bandwidth allocation.
The Internet is a data transport network including legacy networks and optical networks. The legacy networks exist at the outer edge of the Internet and use copper wires to connect client systems and electronic routers/switches. The optical networks form the backbone of the Internet and use fibers to connect optical cross-connects or switches. Between the legacy networks and optical networks are edge devices, which are electro-optic.
Well-developed optical transport technology brings an ever-increasing amount of bandwidth to the Internet. However, with conventional network technology, end clients have little ability to exploit optical network resources for their own purposes. As a result, there is abundant bandwidth available in the backbone of the Internet. In fact, a number of emerging Internet applications such as storage area network and streaming media intend to take greater advantage of the abundant bandwidth. These applications are dynamically initiated and provide a variety of content data over the IP protocol.
More specifically, conventional network technology has the following drawbacks.
1. Static Provisioning of Optical Links
Conventional network resource provisioning establishes fixed links to connect customer networks. For example, the optical provisioning is static, fixed bandwidth, and usually takes a long time, e.g., on the order of a month, because it involves inter-network-provider service negotiations and is accomplished manually.
2. Cost of the Optical Link Bandwidth is Not Divided Among Many Users and Provisioning Bandwidth is Not Flexible
Conventionally, provisioning an optical link (e.g., OC-48) means that a customer owns the full link bandwidth (i.e., 2.5 Gbps). This customer is fully responsible for the cost of the optical link. The cost is significant and the optical link bandwidth use is often inefficient. On the other hand, a number of users can share an optical link but they are not guaranteed a specified portion of the bandwidth.
3. Existing Signaling Protocols Not Supported by Optical Gear
Applications can send their bandwidth requirements to the network using existing Internet signaling protocols such as Resource Reservation Protocol (RSVP). These protocols are at the Internet protocol (IP) layer, i.e., the layer 3 (L3), of the ISO Open System Interconnection reference model and require hardware support at network devices. However, optical devices perform data transport at the physical (L1) or the link (L2) layer and thus application signals are not processed in optical networks.
4. Optical Bandwidth Provisioning is Not Aware of the Content of Application Traffic
Conventional bandwidth provisioning is based on the TCP/IP characteristics of traffic flow, which include IP protocol types, source and destination IP addresses, and TCP/UDP source and destination port numbers of traffic packets. Such provisioning is limited for L4 or higher-layer content differentiation because a client may use applications that deal with multiple content traffic streams at the same time. For example, audio and video applications employ different types of content and have different bandwidth requirements. On the other hand, optical networks do not support content differentiation because optical devices do not process IP packets.
Prior attempts to solve the problems described above include the following.
RSVP is the Intserv Reservation Protocol under the Internet Engineering Task Force (IETF) and is used by applications to signal the network for bandwidth reservations for IP traffic. However, RSVP is thought to be not scalable because backbone routers cannot maintain the flow status for all reserved traffic passing by. In addition, optical gear does not accept RSVP signals from end applications because RSVP is an L3 IP protocol.
Within an asynchronous transfer mode (ATM) network, applications can invoke the ATM user-network interface (UNI) to establish virtual circuits with particular bandwidth assignments. However, the ATM UNI is not applicable for non-ATM applications.
GMPLS (Generalized MultiProtocol Label Switching) is a known protocol of traffic path establishment for next-generation optical network. GMPLS is applied with the emerging ASTN (Automatic Switch Transport Network) technology. However, GMPLS does not support granular bandwidth requests from individual clients nor does it allocate bandwidth based on the content of application traffic.
Thus, there remains a need to more fully and effectively exploit the abundant bandwidth existing at optical networks.
SUMMARY OF THE INVENTION
The present invention relates to content-aware dynamic network resource allocation. In one embodiment the network resource of interest is optical bandwidth and this embodiment is termed content-aware dynamic optical bandwidth allocation (CADOBA). Although the following often refers to the CADOBA embodiment, those of skill in the art will appreciate that one can use the present invention to allocate other network resources in addition to bandwidth. CADOBA enables clients at end legacy networks to manipulate the network resources of backbone optical networks for their own purposes. One embodiment of the invention provides three intelligent mechanisms: 1) a gateway mechanism operative to transform application requests in an application transparent way to intelligent network control; 2) a provisioning mechanism operative to perform optical link or lightpath setup and bandwidth allocation; and 3) a classification mechanism operative to differentiate application traffic based on L4+ content characteristics and to forward content streams to the provisioned routes (optical links or lightpaths).
Another embodiment of the invention provides a method for performing content-aware optical bandwidth allocation over a network including an edge device and an optical control unit. Typically networks include client systems, legacy networks, optical networks and edge devices connecting the legacy networks with the optical networks. Both legacy and optical networks have network control units. A control unit can be a part of a network device, or it can be an associated device. Both legacy and optical networks have network domains. An ISP network is an example of a network domain. All network devices in a network domain are managed in a similar way.
The method includes: receiving signal traffic of applications from the edge device; determining a network resource request for a particular application data traffic with content specification from a received signal; communicating with an optical control unit to allocate a network resource to provide a network resource provisioned route, and creating rule data for the edge device to forward content-specific application traffic onto the network resource provisioned route.
Still another embodiment of the invention provides a system for performing content aware optical bandwidth allocation over a network including an edge device and an optical control unit. The system includes a gateway module, a provisioning module in communication with the gateway module and a classification module in communication with the gateway module.
The gateway module, in communication with the edge device, receives signal traffic of applications from the edge device and determines, from the signal traffic, a bandwidth request associated with a content-specified traffic.
The provisioning module receives a provisioning request from the gateway module regarding the bandwidth request for specified content traffic, and communicates with an optical control unit to allocate optical bandwidth to provide a provisioned optical route. The provisioning module also communicates with the edge device to allocate the appropriate bandwidth for the content-specified traffic forwarding towards a provisioned optical route;
The classification module receives a content classification request from the gateway module, and, based on the classification request, creates a content-aware traffic routing rule for the edge device to forward specified content traffic to the provisioned bandwidth route.
These and other features of the invention are more fully set forth with reference to the following detailed description and the accompanying drawings.