Local congestion mitigation
Local Congestion Mitigation re-routes traffic around a congested network segment without regard for end point destinations of the re-routed traffic. By inhibiting consideration of end point destinations, determinations of alternate routes are simplified relative to techniques that compute new end-to-end routes for traffic when a congested segment is encountered. These methods therefore remain relatively efficient as a network grows in size and network routes within the network become increasingly complex.
1. A method comprising:
determining that a network path between a source network node and a destination network node includes a network segment between a first intermediate network node and a second intermediate network node;
determining that the network segment between the first intermediate network node and the second intermediate network node is experiencing congestion caused by network traffic;
implementing a multiple segment list Tactical Traffic Engineering policy at the first intermediate network node using Unequal Cost Multi-Path routing to split the network traffic between multiple segments between the first intermediate network node and the second intermediate network node, wherein implementing includes splitting the network traffic between the multiple segments between the first intermediate network node and the second intermediate network node using weights; and
correcting for uneven equal cost multi-path splitting by adjusting the weights used for the Unequal Cost Multi-Path routing.
2. The method of claim 1 , comprising:
configuring a one-hop segment routing (SR) policy to collect traffic measurements between the first intermediate network node and the second intermediate network node;
deploying the one-hop SR policy at the first intermediate network node;
receiving the traffic measurements; and
estimating an amount of traffic based on the traffic measurements,
wherein implementing the multiple segment list Tactical Traffic Engineering policy is based on the amount of traffic.
3. The method of claim 1 , further comprising determining a network topology based on one or more of border gateway protocol-link state messages (BGP-LS), simple network management protocol (SNMP) messages, or path computation element protocol (PCEP) messages, wherein implementing the multiple segment list Tactical Traffic Engineering policy is based on the network topology.
4. The method of claim 1 , further comprising:
determining a difference between a traffic demand of the network segment and a nominal utilization of the network segment; and
determining the multiple segment list Tactical Traffic Engineering policy based on the difference.
5. The method of claim 1 , wherein the second intermediate network node is a next hop for packets received at the first intermediate network node along the network path, wherein the first intermediate network node is identified by a first network address and the second intermediate network node is identified by a second network address.
6. The method of claim 5 , wherein the network traffic comprises traffic provided from the source network node to the destination network node.
7. The method of claim 6 , further comprising:
identifying, based on the congestion, and the second network address and independent of network segments from the source network node to the first intermediate network node and network segments from the second intermediate network node to the destination network node, a first set of alternate routes from the first intermediate network node to the second intermediate network node; and
rerouting a first portion of the network traffic over an alternate route in the first set of alternate routes.
8. An apparatus comprising:
one or more network interfaces configured to enable network communications;
one or more processors; and
one or more memories storing instructions that when executed configure the one or more processors to perform operations comprising:
determining that a network path between a source network node and a destination network node includes a network segment between a first intermediate network node and a second intermediate network node;
determining that the network segment between the first intermediate network node and the second intermediate network node is experiencing congestion caused by network traffic;
implementing a multiple segment list Tactical Traffic Engineering policy at the first intermediate network node using Unequal Cost Multi-Path routing to split the network traffic between multiple segments between the first intermediate network node and the second intermediate network node, wherein implementing includes splitting the network traffic between the multiple segments between the first intermediate network node and the second intermediate network node using weights; and
correcting for uneven equal cost multi-path splitting by adjusting the weights used for the Unequal Cost Multi-Path routing.
9. The apparatus of claim 8 , the operations further comprising:
configuring a one-hop segment routing (SR) policy to collect traffic measurements between the first intermediate network node and the second intermediate network node;
deploying the one-hop SR policy at the first intermediate network node;
receiving the traffic measurements; and
estimating an amount of traffic based on the traffic measurements,
wherein implementing the multiple segment list Tactical Traffic Engineering policy is based on the amount of traffic.
10. The apparatus of claim 8 , the operations further comprising determining a network topology based on one or more of border gateway protocol-link state messages (BGP-LS), simple network management protocol (SNMP) messages, or path computation element protocol (PCEP) messages, wherein implementing the multiple segment list Tactical Traffic Engineering policy is based on the network topology.
11. The apparatus of claim 8 , the operations further comprising:
determining a difference between a traffic demand of the network segment and a nominal utilization of the network segment; and
determining the multiple segment list Tactical Traffic Engineering policy based on the difference.
12. The apparatus of claim 8 , wherein the second intermediate network node is a next hop for packets received at the first intermediate network node along the network path, wherein the first intermediate network node is identified by a first network address and the second intermediate network node is identified by a second network address.
13. The apparatus of claim 12 , wherein the network traffic comprises traffic provided from the source network node to the destination network node.
14. The apparatus of claim 13 , the operations further comprising:
identifying, based on the congestion, and the second network address and independent of network segments from the source network node to the first intermediate network node and network segments from the second intermediate network node to the destination network node, a first set of alternate routes from the first intermediate network node to the second intermediate network node; and
rerouting a first portion of the network traffic over an alternate route in the first set of alternate routes.
15. One or more tangible non-transitory storage mediums comprising instructions that when executed configure one or more processors to perform operations comprising:
determining that a network path between a source network node and a destination network node includes a network segment between a first intermediate network node and a second intermediate network node;
determining that the network segment between the first intermediate network node and the second intermediate network node is experiencing congestion caused by network traffic;
implementing a multiple segment list Tactical Traffic Engineering policy at the first intermediate network node using Unequal Cost Multi-Path routing to split the network traffic between multiple segments between the first intermediate network node and the second intermediate network node, wherein implementing includes splitting the network traffic between the multiple segments between the first intermediate network node and the second intermediate network node using weights; and
correcting for uneven equal cost multi-path splitting by adjusting the weights used for the Unequal Cost Multi-Path routing.
16. The one or more tangible non-transitory storage mediums of claim 15 , the operations further comprising:
configuring a one-hop segment routing (SR) policy to collect traffic measurements between the first intermediate network node and the second intermediate network node;
deploying the one-hop SR policy at the first intermediate network node;
receiving the traffic measurements; and
estimating an amount of traffic based on the traffic measurements,
wherein implementing the multiple segment list Tactical Traffic Engineering policy is based on the amount of traffic.
17. The one or more tangible non-transitory storage mediums of claim 15 , the operations further comprising determining a network topology based on one or more of border gateway protocol-link state messages (BGP-LS), simple network management protocol (SNMP) messages, or path computation element protocol (PCEP) messages, wherein implementing the multiple segment list Tactical Traffic Engineering policy is based on the network topology.
18. The one or more tangible non-transitory storage mediums of claim 15 , wherein the second intermediate network node is a next hop for packets received at the first intermediate network node along the network path, wherein the first intermediate network node is identified by a first network address and the second intermediate network node is identified by a second network address.
19. The one or more tangible non-transitory storage mediums of claim 18 , wherein the network traffic comprises traffic provided from the source network node to the destination network node.
20. The one or more tangible non-transitory storage mediums of claim 19 , the operations further comprising:
identifying, based on the congestion, and the second network address and independent of network segments from the source network node to the first intermediate network node and network segments from the second intermediate network node to the destination network node, a first set of alternate routes from the first intermediate network node to the second intermediate network node; and
rerouting a first portion of the network traffic over an alternate route in the first set of alternate routes.