PROMISCUOUS DETECTION AND INTERCEPTED FORWARDING BY PARENT NETWORK DEVICE IN A STORING-MODE TREE-BASED NETWORK

• US 20170223700A1
• Filed: 01/29/2016
• Published: 08/03/2017
• Est. Priority Date: 01/29/2016
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: VASSEUR, JEAN-PHILIPPE, LEVY-ABEGNOLI, ERIC MICHEL, THUBERT, PASCAL, WETTERWALD, PATRICK
• Granted Patent: US 10,244,525 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 12/44 Star or tree networks
• CPC Class Codes: H04L 2012/445 with switching in a hub, e.g. ETHERNET switch
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames

Abstract

In one embodiment, a method comprises: promiscuously detecting, by a parent network device in a tree-based network topology, a data packet transmitted to a child network device attached to the parent network device, the data packet transmitted by a grandchild network device attached to the child network device; determining, by the parent network device, whether the data packet transmitted to the child network device is to be forwarded toward a destination via the parent network device; and the parent network device selectively initiating intercepted forwarding of the data packet toward the destination, on behalf of the child network device, based on determining that the data packet is to be forwarded toward the destination via the parent network device.

Claims

1. A method comprising:

promiscuously detecting, by a parent network device in a tree-based network topology, a data packet transmitted to a child network device attached to the parent network device, the data packet transmitted by a grandchild network device attached to the child network device;

determining, by the parent network device, whether the data packet transmitted to the child network device is to be forwarded toward a destination via the parent network device; and

the parent network device selectively initiating intercepted forwarding of the data packet toward the destination, on behalf of the child network device, based on determining that the data packet is to be forwarded toward the destination via the parent network device.

2. The method of claim 1, wherein the promiscuously detecting is based on the parent network device monitoring a timeslot delegated by the parent network device for transmission of the data packet by the grandchild network device to the child network device.

3. The method of claim 2, wherein the initiating intercepted forwarding comprises sending, to the child network device, an acknowledgement during the timeslot allocated for transmission by the grandchild network device to the child network device, the acknowledgement indicating reception of the data packet and causing the child network device to halt any forwarding of the data packet toward the parent network device.

4. The method of claim 2, further comprising the parent network device allocating a chunk comprising a plurality of said timeslots delegated by the parent network device, enabling the child network device to allocate the corresponding timeslot to the grandchild network device.

5. The method of claim 1, wherein the determining is based on identifying, from a routing information base in the parent network device, whether:

the destination is reachable via the child network device;

or

the child network device is required to forward the data packet to the parent network device.

6. The method of claim 5, wherein the identifying that the child network device is required to forward the data packet to the parent network device is based on one of:

an absence in the routing information base of any reachability information for the destination;

or

an entry in the routing information base specifying the destination is reachable via a second child attached to the parent network device.

7. The method of claim 5, further comprising:

the parent network device receiving, from the child network device, an advertisement specifying the destination is reachable via the child network device; and

the parent network device updating the routing information base, in response to the advertisement, specifying the destination is reachable via the child network device;

the parent network device dropping the data packet in response to determining the destination is reachable via the child network device.

8. An apparatus comprising:

a device interface circuit configured for promiscuously detecting a data packet transmitted to a child network device attached to the apparatus, the apparatus operating as a parent network device in a tree-based network topology, the data packet transmitted by a grandchild network device attached to the child network device; and

a processor circuit configured for determining whether the data packet transmitted to the child network device is to be forwarded toward a destination via the parent network device, the processor circuit further configured for selectively initiating intercepted forwarding of the data packet toward the destination, on behalf of the child network device, based on determining that the data packet is to be forwarded toward the destination via the parent network device.

9. The apparatus of claim 8, wherein the promiscuously detecting is based on the device interface circuit monitoring a timeslot delegated by the processor circuit for transmission of the data packet by the grandchild network device to the child network device.

10. The apparatus of claim 9, wherein the processor circuit is configured for generating, for transmission by the device interface circuit to the child network device, an acknowledgement during the timeslot allocated for transmission by the grandchild network device to the child network device, the acknowledgement indicating reception of the data packet and causing the child network device to halt any forwarding of the data packet toward the parent network device.

11. The apparatus of claim 9, wherein the processor circuit is configured for allocating a chunk comprising a plurality of said timeslots delegated by the parent network device, enabling the child network device to allocate the corresponding timeslot to the grandchild network device.

12. The apparatus of claim 8, further comprising a memory circuit configured for storing a routing information base, the processor circuit configured for identifying, from the routing information base, whether:

the destination is reachable via the child network device;

or

the child network device is required to forward the data packet to the parent network device.

13. The apparatus of claim 12, wherein the processor circuit is configured for identifying that the child network device is required to forward the data packet to the parent network device is based on one of:

an absence in the routing information base of any reachability information for the destination;

or

an entry in the routing information base specifying the destination is reachable via a second child attached to the parent network device.

14. The apparatus of claim 12, wherein:

the device interface circuit is configured for receiving, from the child network device, an advertisement specifying the destination is reachable via the child network device;

the processor circuit is configured for updating the routing information base, in response to the advertisement, specifying the destination is reachable via the child network device;

the processor circuit is configured for dropping the data packet in response to determining the destination is reachable via the child network device.

15. One or more non-transitory tangible media encoded with logic for execution by a machine and when executed by the machine operable for:

promiscuously detecting, by the machine operating as a parent network device in a tree-based network topology, a data packet transmitted to a child network device attached to the parent network device, the data packet transmitted by a grandchild network device attached to the child network device;

determining, by the parent network device, whether the data packet transmitted to the child network device is to be forwarded toward a destination via the parent network device; and

the parent network device selectively initiating intercepted forwarding of the data packet toward the destination by the parent network device, on behalf of the child network device, based on determining that the data packet is to be forwarded toward the destination via the parent network device.

16. The one or more non-transitory tangible media of claim 15, wherein the promiscuously detecting is based on the parent network device monitoring a timeslot delegated by the parent network device for transmission of the data packet by the grandchild network device to the child network device.

17. The one or more non-transitory tangible media of claim 16, wherein the initiating intercepted forwarding comprises sending, to the child network device, an acknowledgement during the timeslot allocated for transmission by the grandchild network device to the child network device, the acknowledgement indicating reception of the data packet and causing the child network device to halt any forwarding of the data packet toward the parent network device.

18. The one or more non-transitory tangible media of claim 15, wherein the determining is based on identifying, from a routing information base in the parent network device, whether:

the destination is reachable via the child network device;

or

the child network device is required to forward the data packet to the parent network device.

19. The one or more non-transitory tangible media of claim 18, wherein the identifying that the child network device is required to forward the data packet to the parent network device is based on one of:

an absence in the routing information base of any reachability information for the destination;

or

an entry in the routing information base specifying the destination is reachable via a second child attached to the parent network device.

20. The one or more non-transitory tangible media of claim 18, further operable for:

the parent network device receiving, from the child network device, an advertisement specifying the destination is reachable via the child network device; and

the parent network device updating the routing information base, in response to the advertisement, specifying the destination is reachable via the child network device;

the parent network device dropping the data packet in response to determining the destination is reachable via the child network device.