# Patent

## Title
Multipath overlay network and its multipath management protocol

## Abstract

A method of wireless communication includes aggregating data in a streaming communication session from a source node in a destination aggregator node, wherein data in the streaming session is transported over multiple paths from the source node to the aggregator node via a multipath overlay network discovered by the source node and the aggregator node.

## Background
BACKGROUND
1. Field
The present disclosure relates generally to communication networks, and more particularly, communication access in Wireless Wide Area Networks (WWANs).
2. Background
Access links, such as a wireless air interface between an access terminal and a base station, are often times the bottlenecks of Wireless Wide Area Networks (WWANs). Nowadays, multimedia applications increasingly introduce a higher traffic load on access links of WWANs, causing unsatisfactory user experience.
SUMMARY
While the capacity of the access link of a device may be limited, the device may use multiple cooperative devices to increase its access capacity. More specifically, an out of band link between the primary node and its cooperative node in conjunction with the access link of the cooperative node may provide an alternative path to the WWAN for the primary node's traffic. Hence, multiple paths can be established between a source and its destination for an application stream.
An overlay network can manage multiple paths for an application stream. In this way, the multipath overlay network is on top of and compatible with the existing network infrastructure. Further, the multipath overlay network may only be perceived as an application by the underlying network.
The instant specification describes an overlay network architecture that serves as a multipath transportation facility between traffic sources and destinations. The multiple paths provided by this multipath overlay network between a pair of source and destination nodes can be used to transport multiple descriptions of a traffic application stream.
The multipath overlay network architecture may be built on top of, and may be compatible with the existing network infrastructure. Interested applications can use the multipath transportation facility provided by this multipath overlay network to enhance its traffic performance, such as throughput, reliability, delay jitter, etc.
In an aspect of the disclosure, a source apparatus includes a processing system and a memory coupled to the processing system. The processing system is configured to support a multimedia communication session for sending data over a plurality of paths from the source to an aggregator, where a first path of the plurality of paths includes at least one helper node selected by the source or the aggregator.
In another aspect of the disclosure, an aggregator apparatus includes a processing system and a memory coupled to the processing system. The processing system is configured to support a multimedia communication session for sending data over a plurality of paths from a source to the aggregator, where a first path of the plurality of paths includes at least one helper node selected by the source or the aggregator.
In still another aspect of the disclosure, an aggregator helper apparatus includes a processing system and a memory coupled to the processing system. The processing system is configured to support a multimedia communication session for sending data over a plurality of paths from a source to the aggregator, where a first path of the plurality of paths includes the aggregator helper, selected by the aggregator.
In yet another aspect of the disclosure, a source helper apparatus includes a processing system and a memory coupled to the processing system. The processing system is configured to support a multimedia communication session for sending data over a plurality of paths from a source to the aggregator, where a first path of the plurality of paths comprising the source helper, selected by the source.
Another aspect of the disclosure provides a method of communication from a source. The method includes supporting a multimedia communication session for sending data over a plurality of paths from the source to an aggregator, where a first path of the plurality of paths includes at least one helper node selected by the source or the aggregator.
In another aspect of the disclosure, a method of communication from an aggregator is provided. The method includes supporting a multimedia communication session for sending data over a plurality of paths from a source to the aggregator, where a first path of the plurality of paths includes at least one helper node selected by the source or the aggregator.
In another aspect of the disclosure, a method of communication from an aggregator is provided. The method includes supporting a multimedia communication session for sending data over a plurality of paths from a source to the aggregator, where a first path of the plurality of paths includes at least one helper node selected by the source or the aggregator.
Yet another aspect of the disclosure provides a method of communication utilizing a source helper. The method includes supporting a multimedia communication session for sending data over a plurality of paths from a source to an aggregator, where a first path of the plurality of paths includes the source helper, selected by the source.
In another aspect of the disclosure, a source apparatus includes means for supporting a multimedia communication session for sending data over a plurality of paths from the source to an aggregator, where a first path of the plurality of paths includes at least one helper node; and means for selecting, by the source, the at least one helper node.
In still another aspect of the disclosure, an aggregator apparatus includes means for supporting a multimedia communication session for sending data over a plurality of paths from a source to the aggregator, where a first path of the plurality of paths includes at least one helper node; and means for selecting, by the aggregator, the at least one helper node.
Yet another aspect of the disclosure provides an aggregator helper apparatus. The aggregator helper apparatus includes means for supporting a multimedia communication session for sending data over a plurality of paths from a source to an aggregator, where a first path of the plurality of paths includes the aggregator helper; and means for receiving a selection by the aggregator.
Still another aspect of the disclosure provides a source helper apparatus. The source helper includes means for supporting a multimedia communication session for sending data over a plurality of paths from a source to an aggregator, where a first path of the plurality of paths includes the source helper; and means for receiving a selection by the source.
In still another aspect of the disclosure, a computer program product includes a computer-readable medium having code for supporting a multimedia communication session for sending data over a plurality of paths from a source apparatus to an aggregator apparatus, where a first path of the plurality of paths includes at least one helper node selected by the source or the aggregator.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.
FIG. 2 is an illustration of a multipath overlay network.
FIG. 3 illustrates a protocol stack of the overlay network data plane.
FIG. 4 illustrates a protocol stack of the control plane.
FIG. 5 illustrates an example of a label distribution.
FIG. 6 illustrates a state transition diagram.
FIGS. 7A-7F illustrate Specification and Description Language (SDL) diagrams for an Aggregator.
FIG. 8 illustrates a state transition diagram for an aggregator helper.
FIGS. 9A-9B illustrate an SDL diagram for an aggregator helper.
FIG. 10 illustrates a state transition diagram for a source.
FIGS. 11A-11F illustrate an SDL diagram for a source.
FIG. 12 illustrates a state transition diagram for a source helper.
FIGS. 13A-13B illustrate an SDL diagram for a source helper.
FIG. 14 is an example of a packet header of multipath overlay network data packets.
FIG. 15 is an example of a packet header of multipath overlay network signaling messages.



DETAILED DESCRIPTION
The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.
FIG. 1 is a block diagram illustrating an example of a hardware implementation for an apparatus 100 employing a processing system 114. In this example, the processing system 114 may be implemented with a bus architecture, represented generally by the bus 102. The bus 102 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 114 and the overall design constraints. The bus 102 links together various circuits including one or more processors, represented generally by the processor 104, and computer-readable media, represented generally by the computer-readable medium 106. The bus 102 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. A bus interface 108 provides an interface between the bus 102 and a transceiver 110. The transceiver 110 provides a means for communicating with various other apparatus over a transmission medium. Depending upon the nature of the apparatus, a user interface 112 (e.g., keypad, display, speaker, microphone, joystick) may also be provided.
The processor 104 is responsible for managing the bus 102 and general processing, including the execution of software stored on the computer-readable medium 106. The software, when executed by the processor 104, causes the processing system 114 to perform the various functions described infra for any particular apparatus. The computer-readable medium 106 may also be used for storing data that is manipulated by the processor 104 when executing software.
The various concepts presented throughout this disclosure may be implemented across a broad variety of telecommunication systems, network architectures, and communication standards. By way of example, various aspects may be implemented in UMTS systems such as W-CDMA, TD-CDMA, TD-SCDMA, High Speed Packet Access (HSPA), and HSPA+. Various aspects may also be implemented in systems employing Long Term Evolution (LTE) (in FDD, TDD, or both modes), LTE-Advanced (LTE-A) (in FDD, TDD, or both modes), CDMA2000, Evolution-Data Optimized (EV-DO), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra-Wideband (UWB), Bluetooth, and/or any other suitable system. The actual telecommunication standard and/or network architecture employed will depend on the specific implementation and the overall design constraints imposed on the system.
FIG. 2 is an illustration of the architecture of a multipath overlay network 200 in accordance with some aspects of the present disclosure. Here, the multipath overlay network 200 includes various paths between different nodes such as one or more traffic sources (“source”) 210, and one or more traffic destinations (“aggregator”) 220. The source 210 and the aggregator 220 may each “discover” specific “helpers” to establish the paths, and to route substreams of a streaming session between the respective source 210 and aggregator 220. Each multimedia communication session (“streaming session”) may include a source 210, one or more source helpers 215 (optional), one or more aggregator helpers 225 (optional), and an aggregator 210. For example, in one path, a traffic substream may flow from a source 210 to a source helper 215, then to an aggregator helper 225, and then to an aggregator 220. The selected source helper 215 and aggregator helper 225 thus serve to relay the substream of the streaming multimedia communication session from the source 210 to the aggregator 220. If data is transmitted from the source 210 directly to the aggregator 220, that data may be characterized as a first description of the streaming session. Substreams of data transmitted over other paths, e.g., utilizing one or more helpers, may be characterized as second and subsequent descriptions of the streaming session. Thus, multiple descriptions of the streaming session may be transmitted over separate paths and reassembled at the aggregator 220 for an enhanced quality of service by virtue of the additional bandwidth being utilized. The source helper 215 and the aggregator 210 may thus “cooperatively help” the source 110 and the aggregator 120 to achieve, for example, a streaming communication that has a quality greater than a threshold value of quality, in order to enhance a user experience.
In the above-described multipath overlay network 200, the sources 210 are the traffic sources of a streaming session, and the aggregators 220 are the traffic destinations of the streaming session. A source helper 215 is a cooperative node, which may be selected by the source 210 to receive and retransmit a description of the session in a substream. An aggregator helper 225 is a cooperative node, which may be selected by the aggregator 220 to receive and retransmit a description of the session in a substream.
In some aspects of the disclosure, a source helper 215 and an aggregator helper 225 can be a helper for one or more traffic sessions at the same time. That is, a node can take different roles for different traffic sessions, i.e., as a source 210, a source helper 215, an aggregator 220, and/or an aggregator helper 225.
Multipath Overlay Network Protocol Stack
FIG. 3 illustrates protocol stacks of certain nodes in the overlay network data plane in accordance with some aspects of the disclosure. The data plane can be utilized to deliver the multimedia data across the multipath overlay network 200. In some aspects, the data packets may traverse multiple hops on the multipath overlay network 200.
In the illustrated example, various data plane protocol stacks are illustrated for certain nodes in a particular path including a source 302, a source helper 304, an aggregator helper 304, and an aggregator 306. In some aspects, the protocol stack for the source 302 includes a physical layer (PHY) 302a, a medium access control layer (MAC) 302b, an internet protocol layer (IP) 302c, a user datagram protocol/transmission control protocol layer (UDP/TCP) 302d, an overlay routing layer 302e, and a real-time transport protocol layer (RTP) 302f. The protocol stack for the source helper 304 includes, at an input side, a PHY layer 304a1, a MAC layer 304b1, an IP layer 304c1, and a UDP/TCP layer 304d1; and at an output side, a PHY layer 304a2, a MAC layer 304b2, an IP layer 304c2, and a UDP/TCP layer 304d2. The source helper 304 further includes an overlay routing layer 304e. The protocol stack for the aggregator helper 306 includes, at an input side, a PHY layer 306a1, a MAC layer 306b1, an IP layer 306c1, and a UDP/TCP layer 306d1; and at an output side, a PHY layer 306a2, a MAC layer 306b2, an IP layer 306c2, and a UDP/TCP layer 306d2. The aggregator helper 306 further includes an overlay routing layer 306e. The protocol stack for the aggregator 308 includes a PHY layer 308a, a MAC layer 308b, an IP layer 308c, a UDP/TCP layer 308d, an overlay routing layer 308e, and an RTP layer 308f. 
In some aspects, the multipath overlay network 200, utilizing the protocol stack illustrated in FIG. 3, utilizes a UDP or a TCP port (e.g, a predetermined UDP or TCP port) for transporting overlay network data packets.
In some aspects of the disclosure, if a data path segment exists between a pair of nodes in the multipath overlay network 200, an end-to-end UDP/IP transport can be utilized between those nodes. For example, an end-to-end UDP/IP transport can be utilized between the source 302 and the source helper 304; between the source 302 and the aggregator helper 306; between the source helper 304 and the aggregator 308; and between the aggregator helper 306 and the aggregator 308.
FIG. 4 illustrates a protocol stack of the overlay network control plane in accordance with some aspects of the disclosure. The control plane of the multipath overlay network may be used to setup, release, and switch a path in the data plane between a respective source 210 and aggregator 220. In the illustrated example of the overlay network control plane connections between pairs of nodes, each of the respective nodes includes a PHY layer, a MAC layer, an IP layer, and a TCP layer. In addition, each of the respective nodes includes an overlay control layer.
In an aspect of the disclosure, multipath overlay network signaling messages may traverse a single hop on the multipath overlay network. That is, if a data path segment is expected between a respective pair of nodes (e.g., between a source helper 402a and a source 402b; between a source 404a and an aggregator 404b; or between an aggregator 406a and an aggregator helper 406b), TCP/IP transport can be utilized between those nodes. In some implementations, the multipath overlay network uses a transmission control protocol (TCP) port (e.g., a predetermined TCP port) for transporting overlay network signaling messages.
Multipath Overlay Network Routing
The multipath overlay network routing function uses a label switching mechanism to route the data traffic. Here, an input label ID can be used by the source helper 215, the aggregator helper 225, and the aggregator 210 to identify the data packets of a unique stream (e.g., a substream) received by the underlying node. Similarly, an output label ID can be used by the source 210, the source helper 215, and the aggregator helper 225 to identify the data packets of a unique stream (e.g., a substream) to be sent by the underlying node. The input label ID may be assigned by the recipient of the data packet during the signaling phase, and in one aspect, may be unique only from the perspective of the recipient. The output label ID may be assigned by the sender of the data packet.
When a node in the multipath overlay network receives a multipath overlay network data packet, the node examines the input label ID and then sends out this packet to a next hop overlay network address, which may be the destination of the packet in the underlying network. The packet may be tagged with the corresponding output label ID. An example of a switching table is shown in Table 1.







TABLE 1







Switching Table











Input
Output
Next Hop Overlay


Node
Label ID
Label ID
Network Address





Source

X
X


Source Helper
X
X
X


Aggregator Helper
X
X
X


Aggregator
X









FIG. 5 is an illustration of a multipath overlay network substantially similar to that illustrated in FIG. 2, further including details to illustrate distribution of label IDs. In the illustrated example, the label IDs that are assigned by a common node are tagged with the same alphabetic character.
For example, a first overlay network data packet may be sent from source 1 210 along a direct path to aggregator 2 220d. Here, the source 1 210 may assign an output label ID of dl, corresponding to the overlay network address of the aggregator 2 220d; and similarly, because this particular data packet is to follow a direct path, the next hop overlay network address also may correspond to that of aggregator 2 220d. When the data packet arrives at the aggregator 2 220d, the data packet then receives an input label ID corresponding to the overlay network address of the source.
Further, a second overlay network data packet may be sent from source 1 210 along an alternative path to aggregator 2 220d. Here, the alternative path includes source helper 215a and aggregator helper 225b. Thus, the source 1 210 may assign an output label ID of dl, corresponding to the overlay network address of aggregator 2 220d. However, because this particular data packet is following the alternative path, the next hop overlay network address corresponds to that of source helper 215a. At the next hop, the source helper 215a assigns an input label ID corresponding to the overlay network address of source 1 210, since that node was the source of the data packet; and retains the output label ID of aggregator 2 220d. The source helper 215a assigns a next hop overlay network address corresponding to that of the aggregator helper 225b. At the next hop, the aggregator helper 225b assigns an input label ID corresponding to the overlay network address of source helper 215a, and retains the output label ID of aggregator 2 220d. The aggregator helper 225b assigns a next hop overlay network address corresponding to that of aggregator 2 220d. At the next hop, which is the destination of the data packet, aggregator 2 220d assigns an input label ID corresponding to the overlay network address of the aggregator helper 225b. 
Of course, those skilled in the art will recognize that this is only one particular implementation, and other forms of switching tables and addressing of data packets may be utilized within the spirit of the present disclosure and the scope of the claims.
State and SDL Diagrams of an Aggregator
Referring once again to the multipath overlay network 200 illustrated in FIG. 2, it is seen that an aggregator 220 may be capable of receiving information over multiple paths from a corresponding source 210. In an aspect of the disclosure, as illustrated in FIG. 6, an aggregator 220 may include a master state machine that governs the path management of the multiple paths it has with the corresponding source 210. In a further aspect of the disclosure, a master state machine for an aggregator 220 can include multiple atomic state machines. Here, each atomic state machine governs the path management of a single path between the aggregator 220 and the corresponding source 210.
A state transition diagram 600 for an aggregator 220 in accordance with some aspects of the disclosure is shown in FIG. 6. For each atomic state machine of the aggregator 220, the aggregator 220 has states including a Released state 610; a Wait for Aggregator Helper to Join state 620; a Wait for Source to Join state 630; a Joined state 640; a Wait for Aggregator Helper to Replace state 650; and a Wait for Source to Switch state 660. At some of the states, as described below, the aggregator 220 may utilize timers including an Original Helper Join timer, a Replacement Helper Join timer, and a Source Join timer. Further, in some of the states, the aggregator 220 may utilize a binary state variable “helper_active” for state reduction, with, e.g., a default value set to false. Signaling messages that are not designed to be handled as inputs at a certain state may be queued for delayed processing.
FIGS. 7A-7F are specification and description language (SDL) flow charts illustrating state transitions in the state transition diagram 600 illustrated in FIG. 6. As illustrated in FIG. 7A, at the Released state 610, the path between the aggregator 220 and the node corresponding to this particular atomic state machine is released. Here, the aggregator 220 may transition to the Wait for Source to Join state 630 or the Wait for Aggregator Helper to Join state 620. The aggregator 220 may receive an indication 702, e.g., from a source 210, for setting up a path. If the aggregator 220 is not in need of a helper, then the aggregator 220 may move to the Wait for Source to Join state 630. If the aggregator 220 desires a helper, the aggregator 220 may send an Aggregator Helper Join Request message 704 to the corresponding aggregator helper 225, and start an Original Helper Join timer 706. The aggregator 220 may then enter the Wait for Aggregator Helper to Join state 620.
As illustrated in FIG. 7B, at the Wait for Aggregator Helper to Join state 620, the aggregator 220 has sent an Aggregator Helper Join Request message, and is awaiting, for the duration of the Original Helper Join timer, an Aggregator Helper Join Response message. Here, if the Original Helper Join timer expires 708, the aggregator 220 enters the Released state 610. However, prior to the expiration of the Original Helper Join timer, the aggregator 220 may receive an Aggregator Helper Join Response message 710. If the message is not accepted, the aggregator 220 may enter the Released state 610. If the message is accepted, the aggregator 220 may then set the helper_active variable to true 711, send a Source Join Request message 712, start a Source Join timer 714, and enter the Wait for Source to Join state 630.
As illustrated in FIG. 7C, at the Wait for Source to Join state 630, the aggregator 220 has sent a Source Join Request message, and is awaiting, for the duration of the Source Join timer, a Source Join Response message. Here, if the Source Join timer expires 716, and if the helper_active variable is false, the aggregator 220 may enter the Released state 610. However, if the Source Join timer expires 716, and the helper_active variable is true, then the aggregator may wish to release the helper corresponding to the helper_active variable, so it may send a Helper Release Request message 718 to its helper, set the helper_active variable to false, and thereafter enter the Released state 610. However, prior to the expiration of the Source Join timer, the aggregator 220 may receive a Source Join Response message 722 from the source 210 in response to the Source Join Request message. If the aggregator 220 does not accept the Source Join Response message, then the aggregator 220 follows the process outlined just above to enter into the Released state 610. If the aggregator 220 accepts the Source Join Response message from the source 210, then the aggregator 220 enters the Joined state 640.
As illustrated in FIG. 7D, at the Joined state 640, a path from the aggregator 220 to a corresponding source 210 exists, that path including the node corresponding to this particular atomic state machine. Here, the aggregator 220 may receive an Aggregator Switch Request message 724 from the source 210, to request the aggregator 220 to switch a path between the source 210 and the aggregator 220. The aggregator 220 may then respond to the source 210 with an Aggregator Switch Response message 726 and return to the Joined state 640. Further, in the Joined state 640, the aggregator 220 may receive a Helper Release Notification message 728 from a helper node, indicating to release a particular path utilizing that node, between the source 210 and the aggregator 220. Here, to release the path, the aggregator 220 may set the helper_active variable to false 730, and seek to find a replacement helper 732. In the Joined state 640, the aggregator 220 may also receive an indication for replacing a joined helper 734, in response to which the aggregator 220 similarly may seek to find a replacement helper 732. Here, if a replacement helper is not found, the aggregator 220 may send a Source Release Command message 736 to the source 210 to release the path between the source 210 and the aggregator 220, and enter the Released state 610. If a replacement helper is found, the aggregator 220 may send an Aggregator Helper Join Request message 738 to the found aggregator helper 225, seeking to set up the path between the source 210 and the aggregator 220 utilizing the found aggregator helper 225. The aggregator 220 may then start the Replacement Helper Join timer 740, and enter the Wait for Aggregator Helper to Replace state 650. Further, in the Joined state 640, the aggregator 220 may receive a Source Release Notification message 742 from the source 210 indicating to release a path between the source 210 and the aggregator 220. Here, the aggregator 220 may send a Helper Release Command message 744 to a joined helper to release a path between the source 210 and the aggregator 220 utilizing the corresponding helper, and set the helper_active variable false 746, before entering the Released state 610.
As illustrated in FIG. 7E, at the Wait for Aggregator Helper to Replace state 650, the aggregator 220 has sent an Aggregator Helper Join Request message to a found replacement aggregator helper 225, and is awaiting, for the duration of the Replacement Helper Join timer, an Aggregator Helper Join Response message from the found replacement aggregator helper 225. Here, if the Replacement Helper Join timer expires 748, but if the helper_active variable is false (indicating that the aggregator 220 is not joined to a helper node), the aggregator 220 sends a Source Release Command message 750 to the source 210 to release the path between the source 210 and the aggregator 220, and enters the Released state 610. However, if the Replacement Helper Join timer expires 748, and the helper_active variable is true, then the aggregator 220 enters the Joined state 640, retaining the path between the source 210 and the aggregator 220 that includes the helper corresponding to this particular atomic state machine. Further, prior to the expiration of the Replacement Helper Join timer, the aggregator 220 may receive an Aggregator Helper Join Response message 752 from a corresponding aggregator helper 225 in response to an Aggregator Helper Join Request message. If the aggregator 220 does not accept the Aggregator Helper Join Response message, then the aggregator 220 follows the process outlined above to enter into either the Released state 610 or the Joined state 640. If the aggregator 220 accepts the Aggregator Helper Join Response message from the aggregator helper 225, and if the helper_active variable is true, the aggregator 220 may send a Helper Release Command message 754 to the original helper to release the corresponding path between the source 210 and the aggregator 220 utilizing that helper node. If the helper_active variable is false, the aggregator 220 may skip the sending of the Helper Release Command message 754. Next, the aggregator 220 may send a Source Switch Request message 756 to the source 210 to request the source 210 to switch a path between the source 210 and the aggregator 220, start the Source Join timer 758, and enter the Wait for Source to Switch state 660.
As illustrated in FIG. 7F, at the Wait for Source to Switch state 660, the aggregator 220 has sent a Source Switch Request message, and is awaiting, for the duration of the Source Join timer, a Source Switch Response message. Here, if the Source Join timer expires 760, the aggregator 220 may send a Helper Release command 762 to the respective helper, to release the corresponding path between the source 210 and the aggregator 220 utilizing that helper node. The aggregator 220 may then set the helper_active variable to false 764, and enter the Released state 610. However, prior to the expiration of the Source Join timer, the aggregator 220 may receive a Source Switch Response message 766 from the source 210 in response to the Source Switch Request message. If the aggregator 220 does not accept the Source Switch Response message, the aggregator 220 may follow the process outlined just above to enter into the Released state 610. If the aggregator 220 accepts the Source Switch Response message 766, then the aggregator 220 enters the Joined state 640.
State and SDL Diagrams of an Aggregator Helper
FIG. 8 is an illustration of a state machine 800 corresponding to an aggregator helper 225, illustrated in FIG. 2. An aggregator helper 225 may include a Released state 810 and a Joined state 820. That is, the aggregator helper 225 may be joined to take part in forming a path, or may be released as a cooperative node.
FIGS. 9A-9B are SDL flow charts illustrating state transitions in the state transition diagram 800 illustrated in FIG. 8. As illustrated in FIG. 9A, at the Released state 810, the aggregator helper 225 does not act as a cooperative node for a path between a source 210 and an aggregator 220. Here, the aggregator helper 225 may receive an Aggregator Helper Join Request message 902 from an aggregator 220 to request the aggregator helper 225 set up a path between a source 210 and the aggregator 220. If the aggregator helper 225 does not accept the Aggregator Helper Join Request message, the aggregator helper 225 may send a Negative Aggregator Helper Join Response message 904 to the aggregator 220, and return to the Released state 810. If the aggregator helper 225 accepts the Aggregator Helper Join Request message, the aggregator helper 225 may send a Positive Aggregator Helper Join Response message 906 to the aggregator 220, and enter the Joined state 820, in which the aggregator helper 225 acts as a cooperative node in a path between a source 210 and the aggregator 220.
As illustrated in FIG. 9B, at the Joined state 820, the aggregator helper 225 acts as a cooperative node in a path between a source 210 and an aggregator 220. Here, the aggregator helper 225 may receive a Release Indication message 908, indicating to release the path between the source 210 and the aggregator 220, including the aggregator helper 225. In response, the aggregator helper 225 may send a Helper Release Notification message 910 to the aggregator 220 to release the corresponding path. Further, the aggregator helper 225 may receive a Helper Release Command message 912 from an aggregator 220 to release a path between the aggregator 220 and a source 210. Here, the aggregator helper 225 may enter the Released state 810, wherein the aggregator helper 225 does not act as a cooperative node for a path between a source 210 and an aggregator 220.
State and SDL Diagrams of a Source
Referring once again to the multipath overlay network 200 illustrated in FIG. 2, it is seen that a source 210 may be capable of sending information over multiple paths to a corresponding aggregator 220. In an aspect of the disclosure, as illustrated in FIG. 10, a source 210 may include a master state machine that governs the path management of the multiple paths established with the corresponding aggregator 220. In a further aspect of the disclosure, a master state machine for a source 210 can include multiple atomic state machines. Here, each atomic state machine governs the path management of a path between the source 210 and the corresponding aggregator 220.
A state transition diagram 1000 for a source 210 in accordance with some aspects of the disclosure is shown in FIG. 10. For each atomic state machine of the source 210, the source 210 has states including a Released state 1010; a Wait for Source Helper to Join state 1020; a Joined state 1040; a Wait for Source Helper to Replace state 1050; a Wait for Aggregator to Switch state 1060; and a Wait for Source Helper to Switch state 1070. At some of the states, as described below, the source 210 may utilize timers including an Original Helper Join timer, a Replacement Helper Join timer, and an Aggregator Join timer. Further, in some of the states, the source 210 may utilize a binary state variable “helper_active” for state reduction, with, e.g., a default value set to false. Signaling messages that are not designed to be handled as inputs at a certain state may be queued for a delayed processing.
FIGS. 11A-11F are SDF flow charts illustrating state transitions in the state transition diagram 1000 illustrated in FIG. 10. As illustrated in FIG. 11A, at the Released state 1010, the path between the source 210 and the node corresponding to this particular atomic state machine is released. Here, the source 210 may transition to the Joined state 1040 or the Wait for Source Helper to Join state 1020. The source 210 may receive a Source Join Request message 1102 from an aggregator 220 to request the source 210 to setup a path between the source 210 and the aggregator 220. If the source 210 is not in need of a helper, then the source 210 may update path information 1104 to establish a direct path from the source 210 to the aggregator 220, and may move to the Joined state 1040. If the source 210 desires a helper, the source 210 may send a Source Helper Join Request message 1106 to the corresponding source helper 215, and start an Original Helper Join timer 1108. The source 210 may then enter the Wait for Source Helper to Join state 1020.
As illustrated in FIG. 11B, at the Wait for Source Helper to Join state 1020, the source 210 has sent a Source Helper Join Request message, and is awaiting, for the duration of the Original Helper Join timer, a Source Helper Join Response message. Here, if the Original Helper Join timer expires 1110, the source 210 may send a Negative Source Join Response message 1112 to the aggregator 220, and may enter the Released state 1010. However, prior to the expiration of the Original Helper Join timer, the source 210 may receive a Source Helper Join Response message 1114. If the message is not accepted, the source 210 may send a Negative Source Join Response message 1112 to the aggregator 220, and may enter the Released state 1010. If the message is accepted, the source 210 may then set the helper_active variable to true 1116, send a Positive Source Join Response message 1118, and enter the Joined state 1040.
As illustrated in FIG. 11C, at the Joined state 1040, a path from the source 210 to a corresponding aggregator 220 exists, that path including the node corresponding to this particular atomic state machine. Here, the source 210 may receive a Source Switch Request message 1120 from the aggregator 220, to request the source 210 to switch a path between the source 210 and the aggregator 220. If the helper_active variable is false, then the source 210 may update path information 1122 to indicate the new path between the source 210 and the aggregator 220, and may enter the Joined state 1040. However, if the helper_active variable is true, then the source 210 may send a Source Helper Switch Request message 1124 to a source helper 215 to request the source helper 215 to switch a path between the source 210 and the aggregator 220, start the Source Helper Join timer 1126, and enter the Wait for Source Helper to Switch state 1070. Further, in the Joined state 1040, the source 210 may receive a Helper Release Notification message 1128 from a helper node, indicating to release a particular path utilizing that node, between the source 210 and the aggregator 220. Here, to release the path, the source 210 may set the helper_active variable to false 1130, and seek to find a replacement helper 1132. In the Joined state 1040, the source 210 may also receive an indication for replacing a joined helper 1134, in response to which the source 210 similarly may seek to find a replacement helper 1132. Here, if a replacement helper is not found, the source 210 may send a Source Release Notification message 1136 to the aggregator 220 to release the path between the source 210 and the aggregator 220, and enter the Released state 1010. If a replacement helper is found, the source 210 may send a Source Helper Join Request message 1138 to the found source helper 215, seeking to set up the path between the source 210 and the aggregator 220 utilizing the found source helper 215. The source 210 may then start the Replacement Helper Join timer 1140, and enter the Wait for Source Helper to Replace state 1050. Further, in the Joined state 1040, the source 210 may receive a Source Release Command message 1142 from the aggregator 220 indicating to release a path between the source 210 and the aggregator 220. Here, the source 210 may send a Helper Release Command message 1144 to a joined helper to release a path between the source 210 and the aggregator 220 utilizing the corresponding helper, and set the helper_active variable to false 1146, before entering the Released state 1010. Further, in the Joined state 1040, the source 210 may receive an Indication to Release message 1148, in response to which the source 210 may send a Helper Release Command message 1150 to the corresponding helper to release a path between the source 210 and the aggregator 220 utilizing that helper node. The source 210 may then set the helper_active variable to false 1152, send a Source Release Notification message 1154 to the aggregator 220, and enter the Released state 1010.
As illustrated in FIG. 11D, at the Wait for Helper to Switch state 1070, the source 210 has sent a Source Helper Switch Request message, and is awaiting, for the duration of the Original Helper Join timer, a Source Helper Switch Response message. Here, if the Original Helper Join timer expires 1156, the source 210 may send a Helper Release command 1158 to the respective helper, to release the corresponding path between the source 210 and the aggregator 220 utilizing that helper node. The source 210 may then set the helper_active variable to false 1160, and enter the Released state 1010. However, prior to the expiration of the Original Helper Join timer, the source 210 may receive a Source Helper Switch Response message 1166 from the source helper 215 in response to a Source Helper Switch Request message. If the source 210 does not accept the Source Helper Switch Response message, the source 210 may follow the process outlined just above to enter into the Released state 1010. If the source 210 accepts the Source Helper Switch Response message 766, then the source 210 may send a Source Switch Response message 1168 to the aggregator to respond to the Source Switch Request message, and may enter the Joined state 1040.
As illustrated in FIG. 11E, at the Wait for Source Helper to Replace state 1150, the source 210 has sent a Source Helper Join Request message to a found replacement source helper 215, and is awaiting, for the duration of the Replacement Helper Join timer, a Source Helper Join Response message from the found replacement source helper 215. Here, if the Replacement Helper Join timer expires 1170, but if the helper_active variable is false (indicating that the source 210 is not joined to a helper node), the source 210 sends a Source Release Notification message 1172 to the aggregator 220 to release the path between the source 210 and the aggregator 220, and enters the Released state 1010. However, if the Replacement Helper Join timer expires 1170, and the helper_active variable is true, then the source 210 enters the Joined state 1040, retaining the path between the source 210 and the aggregator 220 that includes the helper corresponding to this particular atomic state machine. Further, prior to the expiration of the Replacement Helper Join timer, the source 210 may receive a Source Helper Join Response message 1174 from a corresponding source helper 215 in response to a Source Helper Join Request message. If the source 210 does not accept the Source Helper Join Response message, then the source 210 follows the process outlined above to enter into either the Released state 1010 or the Joined state 1040. If the source 210 accepts the Source Helper Join Response message from the source helper 215, and if the helper_active variable is true, the source 210 may send a Helper Release Command message 1176 to the original helper to release the corresponding path between the source 210 and the aggregator 220 utilizing that helper node. If the helper_active variable is false, the source 210 may skip the sending of the Helper Release Command message 1176. Next, the source 210 may send an Aggregator Switch Request message 1178 to the aggregator 220 to request the aggregator 220 to switch a path between the source 210 and the aggregator 220, start the Aggregator Join timer 1180, and enter the Wait for Aggregator to Switch state 1060.
As illustrated in FIG. 11F, at the Wait for Aggregator to Switch state 1060, the source 210 has sent an Aggregator Switch Request message, and is awaiting, for the duration of the Aggregator Join timer, an Aggregator Switch Response message. Here, if the Aggregator Join timer expires 1182, the source 210 may send a Helper Release command 1184 to the respective helper, to release the corresponding path between the source 210 and the aggregator 220 utilizing that helper node. The source 210 may then set the helper_active variable to false 1186, and enter the Released state 1010. However, prior to the expiration of the Aggregator Join timer, the source 210 may receive an Aggregator Switch Response message 1188 from the aggregator 220 in response to the Aggregator Switch Request message. If the source 210 does not accept the Aggregator Switch Response message, the source 210 may follow the process outlined just above to enter into the Released state 1010. If the source 210 accepts the Aggregator Switch Response message 1188, then the source 210 enters the Joined state 1040.
State and SDL Diagrams of a Source Helper
FIG. 12 is an illustration of a state machine 1200 corresponding to a source helper 215, illustrated in FIG. 2. A source helper 215 may include a Released state 1210 and a Joined state 1220. That is, the source helper 215 may be joined to take part in forming a path, or may be released as a cooperative node.
FIGS. 13A-13B are SDL flow charts illustrating state transitions in the state transition diagram 1200 illustrated in FIG. 12. As illustrated in FIG. 13A, at the Released state 1210, the source helper 215 does not act as a cooperative node for a path between a source 210 and an aggregator 220. Here, the source helper 215 may receive a Source Helper Join Request message 1302 from a source 210 to request the source helper 215 set up a path between the source 210 and an aggregator 220. If the source helper 215 does not accept the Source Helper Join Request message, the source helper 215 may send a Negative Source Helper Join Response message 1304 to the source 210, and return to the Released state 1210. If the source helper 215 accepts the Source Helper Join Request message, the source helper 215 may send a Positive Source Helper Join Response message 1306 to the source 210, and enter the Joined state 1220, in which the source helper 215 acts as a cooperative node in a path between the source 210 and an aggregator 220.
As illustrated in FIG. 13B, at the Joined state 1220, the source helper 215 acts as a cooperative node in a path between a source 210 and an aggregator 220. Here, the source helper 215 may receive a Release Indication 1308, and in response, the source helper 215 may send a Helper Release Notification message 1310 to the source 210 to release the path between the source 210 and an aggregator 220 utilizing the source helper 215. Further, the source helper 215 may receive a Helper Release Command message 1312 from a source 210 to release a path between the source 210 and an aggregator 220. Here, the source helper 215 may enter the Released state 1210, wherein the source helper 215 does not act as a cooperative node for a path between a source 210 and an aggregator 220. Still further, the source helper 215 may receive a Source Helper Switch Request message 1314 from the source 210 to request the source helper 215 to switch a path between the source 210 and an aggregator 220. Here, the source helper 215 may respond by sending a Source Helper Switch Response message 1316 and enter the Joined state 1220.
Multipath Overlay Network Packet Header
An example of a data packet header that may be utilized in multipath overlay network data packets are shown in FIG. 14. The message type field in the packet header of data packets may be set to “data,” and the data payload of the data packets may start immediately after the packet header.
An example of a signaling packet header that may be utilized in multipath overlay network signaling messages is shown in FIG. 15. The payload of the corresponding signaling messages may start immediately after the packet header.
The meanings of the packet header fields for a particular implementation in accordance with some aspects of the disclosure are given in Table 2.







TABLE 2







Packet Header Fields








Field
Description





Version
Version of the overlay network protocol


Ext
When set to 1, indicates that there is an extension header



after the standard header


Message
Overlay network message type


type


Packet
Number of bytes in the payload


length


TTL
Time to live, or number of hops this message can live in the



overlay network


Label ID
Label ID on a one hop link between two overlay network



nodes


Payload
Format of the payload; determines its interpretation by the


type
application









In the “message type” field of the packet header, an information element for characterizing the overlay network message type may be carried. The message types utilized in an exemplary implementation in accordance with some aspects of the present disclosure are listed in Table 3.







TABLE 3







Message Types









Message Type

Data or


Value
Message Type Name
Signaling












0
Data
Data


1
Aggregator Helper Join Request
Signaling


2
Aggregator Helper Join Response
Signaling


3
Source Join Request
Signaling


4
Source Join Response
Signaling


5
Aggregator Switch Request
Signaling


6
Aggregator Switch Response
Signaling


7
Source Switch Request
Signaling


8
Source Switch Response
Signaling


9
Source Helper Join Request
Signaling


10
Source Helper Join Response
Signaling


11
Source Helper Switch Request
Signaling


12
Source Helper Switch Response
Signaling


13
Source Release Command
Signaling


14
Source Release Notification
Signaling


15
Helper Release Command
Signaling


16
Helper Release Notification
Signaling


17-256
Reserved
N/A









Multipath Overlay Network Signaling Messages

Referring now to FIG. 2 and Table 3, in accordance with some aspects of the disclosure, an Aggregator Helper Join Request message may be sent from the aggregator 220 to corresponding aggregator helper 225, in order to request the aggregator helper 225 to set up a path between the source 210 and the aggregator 220. An Aggregator Helper Join Request message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 4.







TABLE 4







Aggregator Helper Join Request Message









Field
Description
Length





Aggregator
Overlay network address of the aggregator: used
32 bits 


address
by the receiver of the Join Request to identify the



its sender


Aggregator
Overlay network address of the aggregator
32 bits 


helper
helper: used by the receiver of the Join Request


address
to check whether this message should be



processed


Transaction
Unique ID of this transaction
8 bits


ID


Label ID
Used for the packet sent from the aggregator
8 bits



helper to the aggregator over this data path


Transport
Transport layer type to be used for the data
4 bits


layer
delivered over this path, such as TCP, UDP, etc.


type


Payload
Payload type of the data delivered over this path
4 bits


Type


Reserved

8 bits









An Aggregator Helper Join Response message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 5. Here, the Aggregator Helper Join Response message may be sent from the aggregator helper 225 to the aggregator 220, in order to respond to a corresponding Aggregator Helper Join Request message.







TABLE 5







Aggregator Helper Join Response Message









Field
Description
Length





Aggregator
Overlay network address of the aggregator
32 bits 


helper
helper: used by the receiver of the Join Response


address
to identify its sender


Aggregator
Overlay network address of the aggregator: used
32 bits 


address
by the receiver of the Join Response to check



whether this message should be processed


Transaction
May be equal to the transaction ID in the
8 bits


ID
corresponding Aggregator Helper Join Request


Response
0x00 = accept; otherwise, reject with various
8 bits


code
reasons


Label ID
Identifies the label ID that should be used for the
8 bits



packet sent from the source or source helper to



the aggregator helper over this data path


Reserved

8 bits









A Source Join Request message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 6. Here, the Source Join Request message may be sent from the aggregator 220 to the source 210 to request the source 210, in order to setup a path between the source 210 and the aggregator 220.







TABLE 6







Source Join Request Message









Field
Description
Length





Aggregator
Overlay network address of the aggregator: used
32 bits 


address
by the receiver of the Join Request to identify its



sender


Source
Overlay network address of the source: used by
32 bits 


address
the receiver of the Join Request to check whether



this message should be processed


Transaction
Unique ID of this transaction
8 bits


ID


Session ID
Uniquely identifies the traffic session to be
32 bits 



delivered over multiple paths between the source



and the aggregator


Path index
Index of the path for this traffic session between
4 bits



the source and the aggregator


Aggregator
Overlay network address of the aggregator
32 bits 


or
helper: may be used by either the source or the


aggregator
source helper


helper


address


Label ID
Used for the packet sent from the source or
8 bits



source helper to the aggregator or aggregator



helper over this data path


Transport
Transport layer type to be used for the data
4 bits


layer
delivered over this path, such as TCP, UDP, etc.


type


Payload
Payload type of the data delivered over this path
4 bits


Type


Reserved

4 bits









A Source Join Response message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 7. Here, the Source Join Response message may be sent from the source 210 to the aggregator 220, in order to respond to a Source Join Request message.







TABLE 7







Source Join Response Message









Field
Description
Length





Source
Overlay network address of the source: used by
32 bits


address
the receiver of the Join Response to identify its



sender


Aggregator
Overlay network address of the aggregator: used
32 bits


address
by the receiver of the Join Response to check



whether this message should be processed


Transaction
May be equal to the transaction ID in the
 8 bits


ID
corresponding Source Join Request message


Response
0x00 = accept; otherwise, reject with various
 8 bits


code
reasons


Source or
Overlay network address of the source or the
32 bits


source
source helper


helper


address









An Aggregator Switch Request message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 8. Here, the Aggregator Switch Request message may be sent from the source 210 to the aggregator 220, in order to request the aggregator 220 to switch a path between the source 210 and the aggregator 220.







TABLE 8





Aggregator Switch Request Message

















Source
Overlay network address of the source: used by
32 bits


address
the receiver of the Switch Request to identify its



sender


Aggregator
Overlay network address of the aggregator: used
32 bits


address
by the receiver of the Switch Request to check



whether this message should be processed


Transaction
Unique ID of this transaction
 8 bits


ID


Session ID
Uniquely identifies the traffic session to be
32 bits



delivered over multiple paths between the source



and the aggregator


Path index
Index of the path for this traffic session between
 4 bits



the source and the aggregator


Source or
Overlay network address of the source or the
32 bits


source
source helper


helper


address


Label ID
Used for the packet sent from the source or
 8 bits



source helper to the aggregator helper over this



data path


Reserved

12 bits









An Aggregator Switch Response message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 9. Here, the Aggregator Switch Response message may be sent from the aggregator 220 to the source 210, in order to respond to an Aggregator Switch Request message.







TABLE 9







Aggregator Switch Response Message









Field
Description
Length





Aggregator
Overlay network address of the aggregator: used
32 bits


address
by the receiver of the Switch Request to identify



its sender


Source
Overlay network address of the source: used by
32 bits


address
the receiver of the Switch Request to check



whether this message should be processed


Transaction
Equal to the transaction ID in the corresponding
 8 bits


ID
Aggregator Switch Request message


Response
0x00 = accept; otherwise, reject with various
 8 bits


code
reasons









A Source Switch Request message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 10. Here, the Source Switch Request message may be sent from the aggregator 220 to the source 210, in order to request the source 210 to switch a path between the source 210 and the aggregator 220.







TABLE 10







Source Switch Request Message









Field
Description
Length





Aggregator
Overlay network address of the aggregator: used
32 bits


address
by the receiver of the Switch Request to identify



its sender


Source
Overlay network address of the source: used by
32 bits


address
the receiver of the Switch Request to check



whether this message should be processed


Transaction
Unique ID of this transaction
 8 bits


ID


Session ID
Uniquely identifies the traffic session to be
32 bits



delivered over multiple paths between the source



and the aggregator


Path index
Index of the path for this traffic session between
 4 bits



the source and the aggregator


Aggregator
Overlay network address of the aggregator or the
32 bits


or old
old aggregator helper


aggregator


helper


address


Old Label
Old label ID used on the packet sent from the
 8 bits


ID
source or source helper to the aggregator or the



aggregator helper over this data path


Aggregator
Overlay network address of the aggregator or the
32 bits


or new
new aggregator helper


aggregator


helper


address


New Label
New label ID to be used on the packet sent from
 8 bits


ID
the source or source helper to the aggregator or



the aggregator helper over this data path


Reserved

 4 bits









A Source Switch Response message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 11. Here, the Source Switch Response message may be sent from the source 210 to the aggregator 220, in order to respond to a Source Switch Request message.







TABLE 11







Source Switch Response Message









Field
Description
Length





Source
Overlay network address of the source: used by
32 bits


address
the receiver of the Switch Response to identify



its sender


Aggregator
Overlay network address of the aggregator: used
32 bits


address
by the receiver of the Switch Response to check



whether this message should be processed


Transaction
Equal to the transaction ID in the corresponding
 8 bits


ID
Source Switch Request message


Response
0x00 = accept; otherwise, reject with various
 8 bits


code
reasons









A Source Helper Join Request message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 12. Here, the Source Helper Join Request message may be sent from the source 210 to the source helper 215, in order to request the source helper 215 to set up a path between the source 210 and the aggregator 220.







TABLE 12







Source Helper Join Request Message









Field
Description
Length





Source
Overlay network address of the source: used by
32 bits 


address
the receiver of the Join Request to identify its



sender


Source
Overlay network address of the source helper:
32 bits 


helper
used by the receiver of the Join Request to check


address
whether this message should be processed


Transaction
Unique ID of this transaction
8 bits


ID


Aggregator
Overlay network address of the aggregator or
32 bits 


or
aggregator helper: used by the source helper as


aggregator
the next hop overlay network address for this


helper
path


address


Label ID
Used by the source helper for the packet sent
8 bits



from the source helper to the aggregator or the



aggregator helper over this data path


Transport
Transport layer type to be used for the data
4 bits


layer
delivered over this path, such as TCP, UDP, etc.


type


Payload
Payload type of the data delivered over this path
4 bits


Type


Reserved

8 bits









A Source Helper Join Response message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 13. Here, the Source Helper Join Response message may be sent from the source helper 215 to the source 210, in order to respond to a Source Helper Join Request message.







TABLE 13







Source Helper Join Response Message









Field
Description
Length





Source
Overlay network address of the source helper:
32 bits 


helper
used by the receiver of the Join Response to


address
identify its sender


Source
Overlay network address of the source: used by
32 bits 


address
the receiver of the Join Response to check



whether this message should be processed


Transaction
Equal to the transaction ID in the corresponding
8 bits


ID
Source Helper Join Request message


Response
0x00 = accept; otherwise, reject with various
8 bits


code
reasons


Label ID
Used for the packet sent from the source to the
8 bits



source helper over this data path


Reserved

8 bits









A Source Helper Switch Request message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 14. Here, the Source Helper Switch Request message may be sent from the source 210 to the source helper 215, in order to request a source helper 215 to switch a path between the source and the aggregator.







TABLE 14







Source Helper Switch Request Message









Field
Description
Length





Source
Overlay network address of the source helper:
32 bits


helper
used by the receiver of the Switch Request to


address
identify its sender


Source
Overlay network address of the source: used by
32 bits


address
the receiver of the Switch Request to check



whether this message should be processed


Transaction
Equal to the transaction ID in the corresponding
 8 bits


ID
Source Helper Switch Request message


Response
0x00 = accept; otherwise, reject with various
 8 bits


code
reasons









A Source Helper Switch Response message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 15. Here, the Source Helper Switch Response message may be sent from the source helper 215 to the source 210, in order to respond to the Source Helper Switch Request message.







TABLE 15







Source Helper Switch Response Message









Field
Description
Length





Source
Overlay network address of the source helper:
32 bits


helper
used by the receiver of the Switch Response to


address
identify its sender


Source
Overlay network address of the source: used by
32 bits


address
the receiver of the Switch Response to check



whether this message should be processed


Transaction
Equal to the transaction ID in the corresponding
 8 bits


ID
Source Helper Switch Request message


Response
0x00 = accept; otherwise, reject with various
 8 bits


code
reasons









A Source Release Command message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 16. Here, the Source Release Command message may be sent from the aggregator 220 to the source 210, in order to release a path between the source 210 and the aggregator 220.







TABLE 16







Source Release Command Message









Field
Description
Length





Aggregator
Overlay network address of the aggregator: used
32 bits


address
by the receiver of the Release Command to



identify its sender


Source
Overlay network address of the source: used by
32 bits


address
the receiver of the Release Command to check



whether this message should be processed


Session ID
Uniquely identify the traffic session to be
32 bits



delivered over multiple paths between the source



and the aggregator


Path index
Index of the path for this traffic session between
 4 bits



the source and the aggregator


Aggregator
Overlay network address of the aggregator or the
32 bits


or
aggregator helper


aggregator


helper


address


Label ID
Label ID used for the packet sent from the source
 8 bits



or source helper to the aggregator or the



aggregator helper over this data path


Reserved

 4 bits









A Source Release Notification message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 17. Here, the Source Release Notification message may be sent from the source 210 to the aggregator 220, in order to release a path between the source 210 and the aggregator 220.







TABLE 17







Source Release Notification Message









Field
Description
Length





Source
Overlay network address of the source: used by
32 bits


address
the receiver of the Release Notification to



identify its sender


Aggregator
Overlay network address of the aggregator: used
32 bits


address
by the receiver of the Release Notification to



check whether this message should be processed


Session ID
Uniquely identify the traffic session to be
32 bits



delivered over multiple paths


Path index
Index of the path for this traffic session
 4 bits


Source or
Overlay network address of the source or the
32 bits


source
source helper


helper


address


Label ID
Label ID used for the packet sent from the source
 8 bits



or source helper to the aggregator or the



aggregator helper over this data path


Reserved

 8 bits









A Helper Release Command message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 18. Here, the Helper Release Command message may be sent from the aggregator 220 or the source 210 to its respective helper 225 or 215, in order to release a path between the aggregator 220 and the source 210.







TABLE 18







Helper Release Command Message









Field
Description
Length





Aggregator
Overlay network address of the aggregator or
32 bits


or
source: used by the receiver of the Release


source
Command to identify its sender


address


Aggregator
Overlay network address of the aggregator helper
32 bits


helper
or source helper: used by the receiver of the


or source
Release Command to check whether this


helper
message should be processed


address


Label ID
Label ID used for the packet sent from the source
 8 bits



or source helper to the aggregator or the



aggregator helper over this data path


Reserved

 8 bits









A Helper Release Notification message for a particular implementation in accordance with some aspects of the disclosure is listed in Table 19. Here, the Helper Release Notification message may be sent from a respective helper 225, 215 to its aggregator 220 or source 210, in order to release a path between the source 210 and the aggregator 220.







TABLE 19







Helper Release Notification Message









Field
Description
Length





Aggregator
Overlay network address of the aggregator helper
32 bits


helper
or source helper: used by the receiver of the


or source
Release Notification to identify its sender


helper


address


Aggregator
Overlay network address of the aggregator or
32 bits


or
source: used by the receiver of the Release


source
Notification to check whether this message


address
should be processed


Label ID
Label ID used for the packet sent from the source
 8 bits



or source helper to the aggregator or the



aggregator helper over this data path.


Reserved

 8 bits









In accordance with various aspects of the disclosure, an element, or any portion of an element, or any combination of elements may be implemented with a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software may reside on a computer-readable medium. The computer-readable medium may be a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip), an optical disk (e.g., compact disk (CD), digital versatile disk (DVD)), a smart card, a flash memory device (e.g., card, stick, key drive), random access memory (RAM), read only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), a register, a removable disk, and any other suitable medium for storing software and/or instructions that may be accessed and read by a computer. The computer-readable medium may also include, by way of example, a carrier wave, a transmission line, and any other suitable medium for transmitting software and/or instructions that may be accessed and read by a computer. The computer-readable medium may be resident in the processing system, external to the processing system, or distributed across multiple entities including the processing system. The computer-readable medium may be embodied in a computer-program product. By way of example, a computer-program product may include a computer-readable medium in packaging materials. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.
Nodes, such as aggregators, sources, their respective helpers, processors contained therein, computer program products, etc., may “support” data transport and communication, as disclosed in the specification, by providing or originating data, as provided, for example, by a source (in one or more substreams containing distinct descriptions of the data), relaying a description of the data in a substream, as provided, for example by a source helper and aggregator helper, and by receiving and aggregating one or more descriptions of the data in respective substreams, as provided, for example, by an aggregator.
It is to be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented unless specifically recited therein.
The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, b and c. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”

## Claims

1. A source apparatus, comprising:
a memory; and
at least one processor coupled to the memory and configured to:
support a multimedia communication session for sending a plurality of distinct portions of data within a same communication session over separate respective paths of a plurality of paths from the source apparatus to an aggregator to reassemble the plurality of distinct portions of data, a first path of the plurality of paths comprising at least one helper node selected by the source apparatus or the aggregator, and
receive a source join request from the aggregator to setup a second path between the source apparatus and the aggregator during the same multimedia communication session.

2. The source apparatus of claim 1, wherein the at least one processor is further configured to send a source helper join request to a source helper to setup the second path.

3. The source apparatus of claim 2, wherein the at least one processor is further configured to receive a source helper join response from the source helper indicating an availability of the source helper to setup the second path.

4. The source apparatus of claim 3, wherein the at least one processor is further configured to send, in response to the source join request, a source join response to the aggregator to indicate an establishment of the second path comprising the source helper.

5. The source apparatus of claim 2, wherein the at least one processor is further configured to establish the second path from the source apparatus to the aggregator, the second path comprising the source helper.

6. The source apparatus of claim 1, wherein the at least one processor is further configured to:
receive a release request indicating to release the first path; and
release the first path.

7. The source apparatus of claim 6, wherein the at least one helper node comprises a source helper, and wherein the release request comprises a helper release notification from the source helper indicating to release the first path between the source apparatus and the aggregator.

8. The source apparatus of claim 7, wherein the at least one processor is further configured to:
seek a second source helper to replace the source helper; and
send a source helper join request to the second source helper to request the second source helper to setup a second path between the source apparatus and the aggregator, the second path comprising the second source helper.

9. The source apparatus of claim 8, wherein the at least one processor is further configured to:
receive a source helper join response from the second source helper indicating an availability of the second source helper to setup the second path.

10. The source apparatus of claim 9, wherein the at least one processor is further configured to send a source helper release command to the source helper to release the first path.

11. The source apparatus of claim 9, wherein the at least one processor is further configured to send an aggregator switch request to the aggregator to request the aggregator to switch to the second path between the source apparatus and the aggregator, the second path comprising the second source helper.

12. The source apparatus of claim 11, wherein the at least one processor is further configured to receive an aggregator switch response from the aggregator; and to establish the second path between the source apparatus and the aggregator, the second path comprising the second source helper.

13. The source apparatus of claim 6, wherein the at least one helper node comprises a source helper, and wherein the release request comprises an indication from the aggregator indicating to release the first path.

14. The source apparatus of claim 13, wherein the at least one processor is further configured to send a source helper release command to the source helper to release the first path.

15. The source apparatus of claim 14, wherein the at least one processor is further configured to send a source release notification to the aggregator to release the first path.

16. The source apparatus of claim 1, wherein the at least one helper comprises a source helper, and wherein the at least one processor is further configured to:
receive a source switch request from the aggregator to request to switch the first path to a second path between the source apparatus and the aggregator;
send a source helper switch request to the source helper to switch the first path to the second path;
receive a source helper switch response from the source helper in response to the source helper switch request;
send a source switch response to the aggregator in response to the source switch request; and
establish the second path between the source apparatus and the aggregator, the second path comprising the source helper.

17. A method of communication from a source, the method comprising:
supporting a multimedia communication session for sending a plurality of distinct portions of data within a same communication session over separate respective paths of a plurality of paths from the source to an aggregator to reassemble the plurality of distinct portions of the data, a first path of the plurality of paths comprising at least one helper node selected by the source or the aggregator; and
receiving a source join request from the aggregator to setup a second path between the source and the aggregator during the same multimedia communication session.

18. The method of claim 17, further comprising:
sending a source helper join request to a source helper to setup the second path.

19. The method of claim 18, further comprising:
receiving a source helper join response from the source helper indicating an availability of the source helper to setup the second path.

20. The method of claim 19, further comprising:
sending, in response to the source join request, a source join response to the aggregator to indicate an establishment of the second path comprising the source helper.

21. The method of claim 18, further comprising:
establishing the second path from the source to the aggregator, the second path comprising the source helper.

22. The method of claim 17, further comprising:
receiving a release request indicating to release the first path; and
releasing the first path.

23. The method of claim 22, wherein the at least one helper node comprises a source helper, and wherein the release request comprises a helper release notification from the source helper indicating to release the first path between the source and the aggregator.

24. The method of claim 23, further comprising:
seeking a second source helper to replace the source helper; and
sending a source helper join request to the second source helper to request the second source helper to setup a second path between the source and the aggregator, the second path comprising the second source helper.

25. The method of claim 24, further comprising:
receiving a source helper join response from the second source helper indicating an availability of the second source helper to setup the second path.

26. The method of claim 25, further comprising:
sending a source helper release command to the source helper to release the first path.

27. The method of claim 25, further comprising:
sending an aggregator switch request to the aggregator to request the aggregator to switch to the second path between the source and the aggregator, the second path comprising the second source helper.

28. The method of claim 27, further comprising:
receiving an aggregator switch response from the aggregator; and to establish the second path between the source and the aggregator, the second path comprising the second source helper.

29. The method of claim 23, wherein the at least one helper node comprises a source helper, and wherein the release request comprises an indication from the aggregator indicating to release the first path.

30. The method of claim 29, further comprising:
sending a source helper release command to the source helper to release the first path.

31. The method of claim 30, further comprising:
sending a source release notification to the aggregator to release the first path.

32. The method of claim 17, wherein the at least one helper comprises a source helper, the method further comprising:
receiving a source switch request from the aggregator to request to switch the first path to a second path between the source and the aggregator;
send a source helper switch request to the source helper to switch the first path to the second path;
receive a source helper switch response from the source helper in response to the source helper switch request;
send a source switch response to the aggregator in response to the source switch request; and
establish the second path between the source and the aggregator, the second path comprising the source helper.