Facilitating IP-based multicasting control connections

One embodiment of the disclosures made herein is an Internet Protocol (IP) multicast control system. In accordance with such IP multicast control system, the IP multicast control system includes a first module capable of facilitating IP multicast control connections between a first apparatus and a second apparatus and a second module capable of enabling termination of a control protocol of the first module. The second module is capable of being supported at an Asynchronous Transfer Mode (ATM) layer of the second apparatus.

FIELD OF THE DISCLOSURE

The disclosures made herein relate generally to Internet Protocol (IP) multicast techniques and more particularly to facilitating IP-based multicasting via a hierarchical network comprising network nodes that are incapable of supporting IP layer capabilities.

BACKGROUND

In conventional implementations of Internet Protocol (IP) multicast control, such control is often performed using a node-by-node, hop-by-hop approach. In this manner, each network node in a particular network of network nodes participates in the control of IP multicast connections. It is required that each network node has awareness at an IP control layer for enabling each network node to participate in the control of IP multicast connections.

Many public and private communication networks include hierarchical networks of Asynchronous Transfer Mode (ATM) layer equipment (i.e. deployed ATM network nodes). To provide new IP-based multicast services within such networks, it is necessary to enable IP multicasting capabilities within such networks. However, it is often not be feasible or desirable to retrofit IP layer capabilities or new hardware into deployed ATM network nodes of such networks.

Insufficient memory in data processors of such deployed ATM network nodes is one reason why it would not be feasible or desirable to retrofit IP layer capabilities into deployed ATM network nodes of such networks. Such insufficient memory limits an ability to terminate an IP stack. Insufficient hardware resources for terminating additional IP connections and traffic is another reason why it is not feasible or desirable to retrofit IP layer capabilities into deployed ATM network nodes of such networks.

The cost and time associated with designing IP-based hardware capable of supporting IP-based multicast services in deployed ATM network nodes is one reason why it is often not desirable (e.g. financially practical) to retrofit such IP-based hardware into deployed ATM network nodes. Similarly, the significant cost associated with retrofitting such IP-based hardware into deployed ATM network nodes is another reason why it is often not desirable to retrofit deployed ATM network nodes with IP-based hardware. Still another reason is that a considerable duration of time and considerable coordination is required for retrofitting such IP-based hardware into a potentially large number of deployed ATM network nodes.

Therefore, facilitating centralized multicast control functionality in a hierarchical network of network elements in a manner that overcomes limitations associated with conventional implementations of IP multicasting capabilities is useful.

DETAILED DESCRIPTION OF THE FIGURES

The disclosures made herein relate to various aspects of centralizing Internet Protocol (IP) multicast control functionality. The term centralized as referred to herein means that such IP multicast control functionality is managed at a single one of a plurality of network nodes. This approach to managing control connections is in contrast to conventional multicast control approaches in which a plurality of network node participate in managing IP multicast control functionality in a node-by-node, hop-by-hop manner. It should be understood that the term centralized does not necessarily refer to a particular location of the network node or apparatus managing such IP multicast control functionality within a network. Accordingly, the network node or apparatus managing such IP multicast control functionality within a network may not be located at a central location within the network.

Embodiments of the disclosures made herein provide a feasible and practical approach to retrofitting IP multicast control capabilities into deployed network nodes that are incapable of supporting IP layer capabilities or that have insufficient IP layer resources for supporting IP multicasting control capabilities. For example, such embodiments of the disclosures made herein enable cost-effective deployment of IP multicasting capabilities in a subtending tree of network elements (e.g. Digital Subscriber Line Access Multiplexors—DSLAMS) that operate at an ATM layer. Effectively, IP functionality is simulated at the ATM layer. It is contemplated herein that the centralized IP multicast control functionality may be integrated into the root of a hierarchical tree of ATM capable network nodes (i.e. a DSLAM), at a network node external to the tree, or within tree.

Turning now to the drawing figures, a communication apparatus100in accordance with a first embodiment of the disclosures made herein is disclosed inFIGS. 1–4. The communication apparatus100includes a hub Digital Subscriber Line Access Multiplexer (DSLAM)102, a first subtended DSLAM104, a second subtended DSLAM106and a plurality of DSL subscriber apparatuses108. Although two subtended DSLAMs are shown, it is contemplated that the communication apparatus100and other apparatuses in accordance with embodiments of the disclosures made herein may include fewer or more than two subtended DSLAMS. A computer system having a DSL modem connected thereto is an example of a DSL subscriber apparatus.

The communication apparatus100depicts an example of a tree of DSLAMs being controlled by the IP gateway module116, wherein the IP gateway module116is internal to the tree. The first and the second subtended DSLAMS (104,106) define a branch of subtended DSLAMs. It is contemplated herein that one or more other branches of subtended DSLAMs (not shown) may be connected to the hub DSLAM102.

It should be understood that that a DSLAM is one example of a network element of a network node. Accordingly, the hub DSLAM102, the first DSLAM104and the second DSLAM106are examples of network elements of respective network nodes. Such respective network nodes may comprise one or more DSLAMs as well as other types of network elements.

The hub DSLAM102includes a network element control module110, a DSL interface module112, a subtending interface module114and an IP gateway module116. The network element control module110, the DSL interface module112, the subtending interface module114and the IP gateway module116are interconnected for enabling communication therebetween. The network element control module110at least partially controls operation of various network elements (e.g. the DSL interface module112, the subtending interface module114and the IP gateway module116, etc) of the hub DSLAM102. The DSL Interface module112enables communication between the hub DSLAM102and the plurality of DSL subscriber apparatus108connected to the hub DSLAM102. The subtending interface module114supports communication between the hub DSLAM102and the first subtended DSLAM104.

The IP gateway module116manages IP multicast control functionality between the hub DSLAM102and at least a portion of the DSLAMs that subtend from the hub DSLAM102(e.g. the first subtending DSLAM104and the second subtending DSLAM106). Managing multicast control connections is an example of managing multicast control functionality. Furthermore, the IP gateway module116manages IP multicast control functionality between the hub DSLAM102and DSL subscriber apparatuses108connected to the Hub DSLAM102and to any subtending DSLAMs under its management. Additional details regarding the operation, implementation and advantages of an IP gateway module in accordance with embodiments of the disclosures made herein are discussed below.

The first subtending DSLAM104includes a network element control module118, a DSL interface module120and a subtending interface module122. The network element control module118, the DSL interface module120and the subtending interface module122are interconnected for enabling communication therebetween. The network element control module118at least partially controls operation of various network elements (e.g. the DSL interface module120and the subtending interface module122) of the first subtending DSLAM104. Furthermore, the network element control module118of the first subtended DSLAM104is connected to the subtending interface module114of the hub DSLAM102, thus enabling communication between the hub DSLAM102and the first subtended DSLAM104. The DSL Interface module120enables communication between the first subtended DSLAM104and the plurality of DSL subscriber apparatuses108connected to the first subtended DSLAM104. The subtending interface module122supports communication between the first subtending DSLAM104and the second subtended DSLAM106.

The second subtending DSLAM106includes a network element control module124, a DSL interface module126and a subtending interface module128. The network element control module124, the DSL interface module126and the subtending interface module128are interconnected for enabling communication therebetween. The network element control module124of the second subtended DSLAM106is connected to the subtending interface module122of the first subtended DSLAM104, thus enabling communication between the first subtended DSLAM104and the second subtended DSLAM106.

The second subtended DSLAM106is capable of providing multicast control functionality that is essentially identical to that of the first subtending DSLAM104. In a first embodiment of the second subtending DSLAM106(shown), the architecture of the second subtending DSLAM106is essentially identical to that of the first subtending DSLAM104. In a second embodiment of the second subtending DSLAM106, the architecture of the second subtending DSLAM106is different than that of the first subtending DSLAM104, although the second subtending DSLAM106is capable of providing multicast control functionality that is essentially identical to that of the first subtending DSLAM104.

As depicted inFIG. 2, the network element control modules (118,124) of the first and the second subtended DSLAMs (104,106) each include a respective control protocol terminating module (119,125). Furthermore, the IP gateway module116is implemented at an IP layer of the hub DSLAM102and the control protocol terminating modules (119,125) are each implemented at an Asynchronous Transfer Mode (ATM) layer of the first and the second subtended DSLAMs (104,106). The control protocol terminating modules (119,125) are capable of terminating a control protocol of the IP gateway module116. In this manner, the IP gateway module116is capable managing multicast control functionality of the first and the second subtended DSLAMs (104,106) and any other suitable configured subtended DSLAMs associated therewith.

It is contemplated herein that in other embodiments of a control protocol terminating module (not shown), the control protocol terminating module may be a separate module (e.g. a separate network element of a network node) rather than a module integrated within a network control module as depicted herein. It is further contemplated herein that functionality of a protocol terminating module in accordance with the disclosures made herein may be integrated with another module (e.g. the network element module, Subtending interface module, etc). In this manner, control protocol terminating functionality is provided without the need for a discrete or integrated control protocol termination module.

As depicted inFIG. 3, centralized multicast control functionality in accordance with the disclosures made herein enable a control connection130to be established between the hub DSLAM102and each DSLAM subtended with respect to the hub DSLAM102(e.g. the first and the second subtended DSLAMs104,106). Accordingly, the IP gateway module116is able to instruct the network element control modules (118,124) of the first and the second subtended DSLAMs (104,106) to perform functions such as establishing and clearing multicast control connections. One or more network elements of each DSLAM (e.g. network element control modules and/or subtending interface modules) participate in enabling each control connection130being established.

As depicted inFIG. 4, centralized multicast control functionality in accordance with the disclosures made herein enable control connections132to be established between the hub DSLAM102and each DSL subscriber apparatuses108of the communication apparatus100such that the DSL subscriber apparatuses108are able to communicate with the IP gateway module116. One or more network elements of each DSLAM (e.g. DSL interface modules, network element control modules and/or subtending interface modules) participate in enabling each control connection132being established.

FIGS. 5–8depict a communication apparatus200in accordance with a second embodiment of the disclosures made herein. The communication apparatus200includes an IP gateway apparatus201, a hub DSLAM202, a first subtended DSLAM204, a second subtended DSLAM206and a plurality of DSL subscriber apparatuses208. Although two subtended DSLAMs are shown, it is contemplated that the communication apparatus200and other apparatuses in accordance with embodiments of the disclosures made herein may include fewer or more than two subtended DSLAMS.

The communication apparatus200depicts an example of a tree of DSLAMs being controlled by the IP gateway201, wherein the IP gateway apparatus201is external to the tree. The first and the second subtended DSLAMS (204,206) define a branch of subtended DSLAMs. It is contemplated herein that one or more other branches of subtended DSLAMs (not shown) may be connected to the hub DSLAM202.

It should be understood that that a DSLAM is one example of a network element of a network node. Accordingly, the hub DSLAM202, the first DSLAM204and the second DSLAM206are examples of network elements of respective network nodes. Such respective network nodes may comprise one or more DSLAMs as well as other types of network elements.

The IP gateway apparatus201includes an IP gateway module216capable of managing IP multicast control functionality between the hub DSLAM202and at least a portion of the DSLAMs that subtend from the hub DSLAM202(e.g. the first subtending DSLAM204and the second subtending DSLAM206). Furthermore, the EP gateway module216manages IP multicast control functionality between the hub DSLAM202and DSL subscriber apparatuses208connected to the Hub DSLAM202and to any subtending DSLAMs under its management. The IP gateway apparatus201is not implemented within the tree of DSLAMs. The IP gateway apparatus201is a device that is capable of being a network element within or adjacent to an ATM network that is serving the subtended tree of DSLAMs. Additional details regarding the operation, implementation and advantages of an IP gateway module in accordance with embodiments of the disclosures made herein are discussed below.

The first subtending DSLAM204includes a network element control module218, a DSL interface module220and a subtending interface module222. The network element control module218, the DSL interface module220and the subtending interface module122are interconnected for enabling communication therebetween. The network element control module218at least partially controls operation of various network elements (e.g. the DSL interface module220and the subtending interface module222) of the first subtending DSLAM204. Furthermore, the network element control module218of the first subtended DSLAM204is connected to the subtending interface module214of the hub DSLAM202, thus enabling communication between the hub DSLAM202and the first subtended DSLAM204. The DSL Interface module220enables communication between the first subtended DSLAM104and the plurality of DSL subscriber apparatuses208connected to the first subtended DSLAM204. The subtending interface module222supports communication between the first subtending DSLAM104and the second subtended DSLAM106.

The second subtending DSLAM206includes a network element control module224, a DSL interface module226and a subtending interface module228. The network element control module224, the DSL interface module226and the subtending interface module228are interconnected for enabling communication therebetween. The network element control module224of the second subtended DSLAM206is connected to the subtending interface module222of the first subtended DSLAM204, thus enabling communication between the first subtended DSLAM204and the second subtended DSLAM206.

The second subtended DSLAM206is capable of providing multicast control functionality that is essentially identical to that of the first subtending DSLAM204. In a first embodiment of the second subtending DSLAM206(shown), the architecture of the second subtending DSLAM206is essentially identical to that of the first subtending DSLAM204. In a second embodiment of the second subtending DSLAM206, the architecture of the second subtending DSLAM206is different than that of the first subtending DSLAM204, although the second subtending DSLAM206is capable of providing multicast control functionality that is essentially identical to that of the first subtending DSLAM204.

As depicted inFIG. 6, the network element control modules (210,218,224) of the hub DSLAM202, first subtended DSLAM204and the second subtended DSLAM206each include a respective control protocol terminating module (211,219,225). Furthermore, the IP gateway module216is implemented at an IP layer of the hub DSLAM202and the control protocol terminating modules (211,219,225) are each implemented at an Asynchronous Transfer Mode (ATM) layer of the hub DSLAM202, the first subtended DSLAM204and the second subtended DSLAM206. The control protocol terminating modules (219,225) are capable of terminating a control protocol of the IP gateway module216. In this manner, the IP gateway module216is capable managing multicast control functionality of the first and the second subtended DSLAMs (204,206) and any other suitable configured subtended DSLAMs associated therewith.

As depicted inFIG. 7, centralized multicast control functionality in accordance with the disclosures made herein enable a control connection230to be established between the IP gateway apparatus201and each one of the DSLAMS (i.e. the hub DSLAM202, the first subtended DSLAM204and the second subtended DSLAM206). Accordingly, the IP gateway module216is able to instruct the network element control modules (218,224) of the hub DSLAM202, the first subtended DSLAM204and the second subtended DSLAM206to perform functions such as establishing and clearing multicast control connections. One or more network elements of each DSLAM (e.g. network element control modules and/or subtending interface modules) participate in enabling each control connection230being established.

Furthermore, as depicted inFIG. 8, centralized multicast control functionality in accordance with the disclosures made herein enable control connections232to be established between the IP gateway apparatus201and each DSL subscriber apparatuses208of the tree of DSLAMs such that the DSL subscriber apparatuses208are able to communicate with the IP gateway apparatus module216. One or more network elements of each DSLAM (e.g. DSL interface modules, network element control modules and/or subtending interface modules) participate in enabling each control connection232being established.

In accordance with at least one embodiment of the disclosures made herein, an IP gateway module and associated control protocol terminating modules each comprise one or more data processor programs implemented on existing deployed network node hardware. In accordance with at least one other embodiment of the disclosures made herein, an IP gateway module and associated control protocol terminating modules may each include respective hardware components in addition to one or more data processor programs. The term data processor program is defined herein to refer to computer software, data processor algorithms or any other type of instruction code capable of controlling operations associated with a data processor. A microprocessor, microcontroller, microcomputer, digital signal processor, state machine, logic circuitry, and/or any device that manipulates digital information based on operational instruction, or in a predefined manner are examples of a data processor. A network element (e.g. an IP gateway module, a control protocol terminating module, a network element controller, etc.) may comprise such a data processor and a data processor program in accordance with embodiments of the disclosures made herein.

It is contemplated herein that functionality associated with the various modules disclosed herein may be integrated in a one or more ancillary modules to a network element control module, a DSL interface module, a subtending interface module and an IP gateway module. Accordingly, multicast control functionality in accordance with the disclosures made herein is not limited to being provided by a single particular module.

One advantage of software of the control protocol terminating module is that its complexity and size is capable of being significantly simpler and smaller than software that would be required to implement comparable multicast control functionality in a conventional distributed (i.e. a node-by-node) manner. Because the size of the software of the control protocol terminating module is capable of being smaller and simpler with an IP Gateway based implementation in accordance with the disclosures made herein, there is greater potential that sufficient memory and processing resources may be found in the existing deployed network nodes. Accordingly, the need to retrofit hardware of the existing deployed network nodes for an IP Gateway based implementation in accordance with the disclosures made herein may be limited, if not avoided.

The IP layer and the ATM layer are examples of a first communication protocol layer and a second communication protocol layer, respectively. It is contemplated herein that multicast control functionality in accordance with the disclosures made herein may be implemented with a combination of communication protocols different than IP and ATM communication protocols. Accordingly, the disclosures made herein are not limited to IP and ATM communication protocols.

FIG. 9depicts a method300for facilitating IP multicasting functionality in accordance with an embodiment of the disclosures made herein. The method300begins at an operation302for implementing centralized multicast control functionality. The operation302for implementing centralized multicast control functionality includes performing a step304for implementing an IP Gateway module at an IP layer of a first network node and performing a step304for implementing a control protocol terminating module at an ATM layer of one or more network nodes (i.e. a second, network node, a third network node, etc) that are in subtending relationship with respect to the first network node. The one or more network nodes are referred to herein as subtending network nodes.

After performing the operation302for implementing centralized multicast control functionality, an operation308is performed for establishing control connections within the network. Accordingly, the operation308for establishing such control connections includes performing a step310for establishing a control connection between the first network node and each of the one or more subtending network nodes and performing an operation312for establishing a control connection between the first network node and one or more subscriber DSL apparatuses that are themselves subtending from a respective one of the subtending network nodes. After the control connections are established with the one or more subtending network nodes and the one or more Subscriber DSL apparatuses, an operation314is capable of being performed for facilitating multicast file download in accordance with known techniques.