Delivering and receiving multicast content across a unicast network
First Claim
1. A method comprising:
- receiving a unicast request message sent from a requesting device to a source of multicast packets with a network device that is intermediate to the requesting device and the source of multicast packets, wherein the unicast request message includes as a destination address an address associated with the source of multicast packets;
determining whether a router alert bit of at least one packet of the unicast request message is set, wherein the router alert bit provides an indication that a device different from the source of the multicast packets is to intercept the unicast request message addressed to the source device;
intercepting and inspecting the unicast request message with an intermediate device when the router alert bit is set;
determining that the unicast request message includes an indication that indicates that the requesting device requests delivery of multicast packets as unicast packets; and
delivering, with the intermediate device, multicast packets received from the source of multicast packets to the requesting device as unicast packets based on the determination that the unicast request message includes the indication;
wherein the intermediate device is unknown to the requesting device at a time when the router alert bit is set.
1 Assignment
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Accused Products
Abstract
Techniques for delivering and receiving multicast content across a unicast network are described. A system that supports delivery and reception of multicast content across a unicast network includes a first device and a second device. The first device may be a destination device or a multicast-enabled router. The second device is multicast-enabled, and may be a multicast-enabled router. The first device determines whether a route between a destination device and a source of multicast packets is multicast-enabled, sends a unicast request message that includes as a destination address an address associated with the source and is marked for interception by a second device based on the determination, and receives the multicast packets as unicast packets from the second device. The second device intercepts the unicast request message and delivers the multicast packets to the requesting device as unicast packets in response to the unicast request message. The unicast request message indicates the address of the source and a group address, i.e., a source/group address pair, associated with the multicast packets that the first device wishes to receive.
175 Citations
61 Claims
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1. A method comprising:
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receiving a unicast request message sent from a requesting device to a source of multicast packets with a network device that is intermediate to the requesting device and the source of multicast packets, wherein the unicast request message includes as a destination address an address associated with the source of multicast packets; determining whether a router alert bit of at least one packet of the unicast request message is set, wherein the router alert bit provides an indication that a device different from the source of the multicast packets is to intercept the unicast request message addressed to the source device; intercepting and inspecting the unicast request message with an intermediate device when the router alert bit is set; determining that the unicast request message includes an indication that indicates that the requesting device requests delivery of multicast packets as unicast packets; and delivering, with the intermediate device, multicast packets received from the source of multicast packets to the requesting device as unicast packets based on the determination that the unicast request message includes the indication; wherein the intermediate device is unknown to the requesting device at a time when the router alert bit is set. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A network device that is intermediate to a requesting device and a source of multicast packets, the network device comprising:
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an interface to receive a unicast request message sent from the requesting device to the source of multicast packets, wherein the unicast request message includes as a destination address an address associated with the source of multicast packets; and a control unit to determine whether a router alert bit of at least one packet of the unicast request message is set, wherein the router alert bit provides an indication that a device different from the source of the multicast packets is to intercept the unicast request message addressed to the source device, intercept and inspect the unicast request message when the router alert bit is set, determine whether the unicast request message includes an indication that indicates that the requesting device requests delivery of multicast packets as unicast packets, and deliver multicast packets received from the source of multicast packets to the requesting device as unicast packets when the unicast request message includes the indication; wherein the network device is unknown to the requesting device when the router alert bit is set. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A computer-readable storage medium comprising instructions that cause a processor to:
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intercept a unicast request message sent from a requesting device to a source of multicast packets at a network device that is intermediate to the requesting device and the source of multicast packets, wherein the unicast request message includes as a destination address an address associated with the source of multicast packets; determine that a router alert bit of at least one packet of the unicast request message is set, wherein the router alert bit provides an indication that a device different from the source of the multicast packets is to intercept the unicast request message that is addressed to the source device; intercept and inspect the unicast request message with an intermediate device based on the determination that the router alert bit is set; determine at the intermediate device that the unicast request message includes an indication that the requesting device requests delivery of multicast packets as unicast packets; and deliver multicast packets received at the intermediate device from the source of multicast packets to the requesting device as unicast packets from the intermediate device based on the determination that the unicast request message includes the indication. - View Dependent Claims (28, 29, 30, 31, 32, 33)
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34. A method comprising:
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determining whether a route from a requesting device to a source of multicast packets is multicast-enabled; and sending a unicast request message from the requesting device to the source of multicast packets based on the determination, wherein the unicast request message includes as a destination address an address associated with the source, and further wherein sending the unicast request message comprises; setting a router alert bit in at least one packet of the unicast request message to cause a network device that is intermediate to the requesting device and the source of multicast packets to intercept and inspect the unicast request message addressed to the source, and including an indication within the unicast request message that indicates to the intermediate network device that the requesting device requests delivery of multicast packets as unicast packets, and wherein the method further comprises, at the requesting device, receiving multicast packets from the source as unicast packets from the intermediate network device; wherein the network device is unknown to the requesting device when the router alert bit is set. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42, 43)
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44. A requesting device comprising a control unit to:
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determine whether a route between the requesting device and a source of multicast packets is multicast-enabled, send a unicast request message to the source of multicast packets based on the determination, wherein the unicast request message includes as a destination address an address associated with the source of multicast packets, set a router alert bit in at least one packet of the unicast request message to cause a network device that is intermediate to the device and the source of multicast packets to intercept and inspect the unicast request message addressed to the source, include an indication within the unicast request message that indicates to the intermediate network device that the requesting device requests delivery of multicast packets as unicast packets, and receive multicast packets from the source as unicast packets from the intermediate network device; wherein the intermediate network device is unknown to the control unit when the router alert bit is set. - View Dependent Claims (45, 46, 47, 48, 49)
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50. A computer-readable storage medium comprising instructions that cause a processor to:
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determine whether a route between a requesting device and a source of multicast packets is multicast-enabled; send a unicast request message from the requesting device to the source of multicast packets based on the determination, wherein the unicast request message is addressed to the source; set a router alert bit in at least one packet of the unicast request message to cause a network device that is intermediate to the requesting device and the source of multicast packets to intercept and inspect the unicast request message addressed to the source, include an indication within the unicast request message that indicates to the intermediate network device that the requesting device requests delivery of multicast packets as unicast packets, and at the requesting device, receive multicast packets from the source as unicast packets from the intermediate network device; wherein the intermediate second device is unknown to the first device when the router alert bit is set. - View Dependent Claims (51, 52, 53, 54)
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55. A system comprising:
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a first device to determine whether a route between the first device and a source of multicast packets is multicast-enabled, send a unicast request message that includes as a destination address an address associated with the source based on the determination, set a router alert bit in at least one packet of the unicast request message to cause a second device that is intermediate to the requesting device and the source of multicast packets to intercept and inspect the unicast request message, include an indication within the unicast request message that indicates to the intermediate second device that the first device requests delivery of multicast packets as unicast packets, and receive multicast packets from the source as unicast packets from the second device; and the intermediate second device, wherein the second device intercepts the unicast request message and delivers the multicast packets from the source to the first device as unicast packets in response to the unicast request message. - View Dependent Claims (56, 57, 58, 59, 60, 61)
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Specification