Transmission priority paths in mesh networks

• US 8,638,667 B2
• Filed: 07/05/2011
• Issued: 01/28/2014
• Est. Priority Date: 07/05/2011
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Shaffer, Shmuel, Vasseur, Jean-Philippe, Shetty, Sandeep J.
• Primary Examiner(s): Wilson, Robert
• Assistant Examiner(s): Aung, Sai
• Application Number:
  US13/176,433
• Publication Number:
  US 20130010798A1
• Time in Patent Office: 938 Days
• Field of Search: 370235-238, 370/328, 370/231, 370/230, 370/243, 370/245, 370/248, 370/254, 709/230, 709/240
• US Class Current: 370/235
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/17 Interaction among intermediate nodes, e.g. hop by hop
• CPC Class Codes: H04L 47/2433 Allocation of priorities to traffic types
• CPC Class Codes: H04L 47/245 using preemption
• CPC Class Codes: H04L 47/724 at intermediate nodes, e.g. resource reservation protocol [RSVP]
• CPC Class Codes: H04L 47/805 QOS or priority aware
• CPC Class Codes: H04L 47/826 Involving periods of time

Abstract

In one embodiment, a node may determine a trigger for establishing transmission priority on a path through a shared-media communication network for priority traffic to a particular node. As such, the node may generate a path clear message (PCM) that would instruct one or more receiving nodes along the path to suspend transmission for traffic other than the priority traffic for a specified duration, and also to transmit a local non-repeated distributed message to one or more neighbor nodes of each respective receiving node, the local non-repeated distributed message to instruct the neighbor nodes to suspend transmission for the specified duration. After transmitting the PCM along the path to the particular node to establish the transmission priority for the priority traffic along the path through the shared-media network, the priority traffic may be transmitted to the particular node along the path during the transmission priority.

Claims

1. A method, comprising:

determining a trigger for establishing transmission priority on a path through a shared-media communication network for priority traffic to a particular node, wherein the trigger is determined to have occurred when a particular data flow has been received at a root node;

in response to determining that the trigger has occurred at the root node, generating a path clear message (PCM), the PCM sent to each node along the path to instruct nodes each node along the path to suspend transmission for traffic other than the priority traffic for a specified duration, and also to transmit a local non-repeated distributed message to one or more neighbor nodes of each respective node along the path, the local non-repeated distributed message to instruct the neighbor nodes to suspend transmission for the specified duration;

transmitting a transmission priority clearing message along the path in response to completion of the transmission priority, the transmission priority clearing message to instruct the each node along the path to resume transmission for other traffic and also to transmit a second local non-repeated distributed message to the neighbor nodes of each respective node along the path, the second local non-repeated distributed message to instruct the neighbor nodes to resume transmission;

transmitting the PCM along the path to the particular node to establish the transmission priority for the priority traffic along the path through the shared-media network; and

transmitting the priority traffic to the particular node along the path during the transmission priority.

2. The method as in claim 1, wherein the specified duration is carried within the PCM.

3. The method as in claim 1, wherein the specified duration is configured within the shared-media network in advance of any PCMs.

4. The method as in claim 1, wherein the local non-repeated distributed message is one of either a broadcast message or a multicast message, and wherein the local non-repeated distributed message has a time-to-live (TTL) value of “

1”

.

5. The method as in claim 1, further comprising:

specifying particular receiving nodes to transmit the local non-repeated distributed message, wherein other receiving nodes not specified along the path that receive the PCM are configured to not transmit the local non-repeated distributed message.

6. The method as in claim 5, wherein the specifying comprises including an indication of the particular receiving nodes within the PCM.

7. The method as in claim 1, wherein the each node along the path and the neighbor nodes of each respective node along the path are configured to resume transmission in response to expiration of a configured timer.

8. The method as in claim 1, wherein the suspending transmission as instructed by the PCM comprises reducing a rate at which traffic other than the priority traffic is transmitted.

9. An apparatus, comprising:

one or more network interfaces to communicate in a shared-media computer network;

a processor coupled to the network interfaces and configured to execute one or more processes; and

a memory configured to store a process executable by the processor, the process when executed operable to;

determine a trigger for establishing transmission priority on a path through a shared-media communication network for priority traffic to a particular node, wherein the trigger is determined to have occurred when a particular data flow has been received at a root node;

generate a path clear message (PCM) in response to a determination that the trigger has occurred at the root node, the PCM sent to each node along the path to instruct one or more each node along the path to suspend transmission for traffic other than the priority traffic for a specified duration, and also to transmit a local non-repeated distributed message to one or more neighbor nodes of each respective node along the path, the local non-repeated distributed message to instruct the neighbor nodes to suspend transmission for the specified duration;

transmit a transmission priority clearing message along the path in response to completion of the transmission priority, the transmission priority clearing message to instruct each node along the path to resume transmission for other traffic and also to transmit a second local non-repeated distributed message to the neighbor nodes of each respective node along the path, the second local non-repeated distributed message to instruct the neighbor nodes to resume transmission;

transmit the PCM along the path to the particular node to establish the transmission priority for the priority traffic along the path through the shared-media network; and

transmit the priority traffic to the particular node along the path during the transmission priority.

10. The apparatus as in claim 9, wherein the process when executed is further operable to:

specify particular receiving nodes to transmit the local non-repeated distributed message, wherein other receiving nodes not specified along the path that receive the PCM are configured to not transmit the local non-repeated distributed message.

11. The apparatus as in claim 9, wherein each node along the path and the neighbor nodes of each respective node along the path are configured to resume transmission in response to expiration of a configured timer.

12. A method, comprising:

receiving, from a root node in response to a particular data flow being received at the root node, a path clear message (PCM) at a receiving node along a path to a particular node in a shared-media communication network, the PCM to instruct the receiving node to suspend transmission for traffic other than the priority traffic for a specified duration, and also to transmit a local non-repeated distributed message to one or more neighbor nodes of the receiving node, the local non-repeated distributed message to instruct the neighbor nodes to suspend transmission for the specified duration;

in response to the PCM;

suspending transmission for traffic other than the priority traffic for the specified duration, and transmitting the local non-repeated distributed message to one or more neighbor nodes of the receiving node, the local non-repeated distributed message to instruct the neighbor nodes to suspend transmission for the specified duration;

receiving a transmission priority clearing message along the path in response to completion of the transmission priority, the transmission priority clearing message to instruct the receiving node to resume transmission for other traffic and also to transmit a second local non-repeated distributed message to the neighbor nodes of each respective receiving node, the second local non-repeated distributed message to instruct the neighbor nodes to resume transmission; and

in response to the transmission priority clearing message;

resuming transmission for traffic other than the priority traffic, and transmitting the second local non-repeated distributed message to one or more neighbor nodes of the receiving node, the second local non-repeated distributed message to instruct the neighbor nodes to resume transmission;

receiving the priority traffic to the particular node during the transmission priority; and

transmitting the priority traffic toward the particular node along the path during the transmission priority.

13. The method as in claim 12, further comprising:

determining whether the specified duration is specified within the PCM; and

if not specified in the PCM, using a duration configured within the shared-media network in advance of any PCMs.

14. The method as in claim 12, wherein the local non-repeated distributed message is one of either a broadcast message or a multicast message, and wherein the local non-repeated distributed message has a time-to-live (TTL) value of “

1”

.

15. The method as in claim 12, further comprising:

determining whether the receiving node is specified as a particular receiving node to transmit the local non-repeated distributed message, wherein other receiving nodes not specified along the path that receive the PCM are configured to not transmit the local non-repeated distributed message.

16. The method as in claim 12, wherein the receiving node and the neighbor nodes of each respective receiving node are configured to resume transmission in response to expiration of a configured timer.

17. The method as in claim 12, further comprising:

prioritizing between a plurality of PCMs.

18. The method as in claim 12, further comprising:

buffering non-priority traffic for transmission after the transmission priority.

19. The method as in claim 12, wherein the suspending transmission as instructed by the PCM comprises reducing a rate at which traffic other than the priority traffic is transmitted.

20. An apparatus, comprising:

one or more network interfaces to communicate in a shared-media computer network;

a processor coupled to the network interfaces and configured to execute one or more processes; and

a memory configured to store a process executable by the processor, the process when executed operable to;

receive, from a root node in response to a particular data flow being received at a root node, a path clear message (PCM) at the apparatus as a receiving node along a path to a particular node in a shared-media communication network, the PCM to instruct the receiving node to suspend transmission for traffic other than the priority traffic for a specified duration, and also to transmit a local non-repeated distributed message to one or more neighbor nodes of the receiving node, the local non-repeated distributed message to instruct the neighbor nodes to suspend transmission for the specified duration;

in response to the PCM;

suspend transmission for traffic other than the priority traffic for the specified duration, and transmit the local non-repeated distributed message to one or more neighbor nodes of the receiving node, the local non-repeated distributed message to instruct the neighbor nodes to suspend transmission for the specified duration;

receive a transmission priority clearing message along the path in response to completion of the transmission priority, the transmission priority clearing message to instruct the receiving node to resume transmission for other traffic and also to transmit a second local non-repeated distributed message to the neighbor nodes of each respective receiving node, the second local non-repeated distributed message to instruct the neighbor nodes to resume transmission; and

in response to the transmission priority clearing message;

resuming transmission for traffic other than the priority traffic, and transmitting the second local non-repeated distributed message to one or more neighbor nodes of the receiving node, the second local non-repeated distributed message to instruct the neighbor nodes to resume transmission;

receive the priority traffic to the particular node during the transmission priority; and

transmit the priority traffic toward the particular node along the path during the transmission priority.