US 8,787,400 B1Granted

Weighted equal-cost multipath

AssigneeJuniper Networks, Inc.

InventorsColby Barth, Kireeti Kompella, David Ward, Joel Obstfeld, Hannes Gredler, John E. Drake

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Abstract

Routers balance network traffic among multiple paths through a network according to an amount of bandwidth that can be sent on an outgoing interface computed for each of the paths. For example, a router receives a link bandwidth for network links that are positioned between the first router and a second router of the network, and selects a plurality of forwarding paths from the first router to the second router. Upon determining that one of the network links is shared by multiple of the plurality of forwarding paths, the router computes a path bandwidth for each of the plurality of outgoing interfaces so as to account for splitting of link bandwidth of the shared network link across the multiple forwarding paths that share the network link. The router assigns packet flows to the forwarding paths based at least on the computed amount of bandwidth for each of the outgoing interfaces.

Claims26

Dependent claims

A method comprising:

receiving, with a first router of a network, a link bandwidth for each of one or more network links of the network that are positioned between the first router and a second router of the network;
identifying, with the first router, a plurality of equal-cost forwarding paths from the first router of the network to the second router of the network;
determining that one of the network links is a common network link shared by multiple of the plurality of equal-cost forwarding paths;
in response to determining that the one of the network links is a common network link shared by multiple of the plurality of equal-cost forwarding paths, computing an amount of bandwidth that can be sent on each of a plurality of outgoing interfaces of the first router for the plurality of equal-cost forwarding paths, wherein computing the amount of bandwidth comprises computing the amount of bandwidth to account for splitting of link bandwidth of the common network link across the multiple equal-cost forwarding paths that share the common network link;
selectively assigning, with the first router, packet flows to each of the plurality of outgoing interfaces based at least on the computed amount of bandwidth;
receiving packets for the packet flows with the first router;
and
forwarding packets of each of the packets flows to the respective one of the plurality of outgoing interfaces to which the packet flow is assigned.

5 more elements

A network device comprising:

a control unit comprising one or more processors;
a routing protocol software of the control unit to receive a link bandwidth for each of one or more network links of a network that are positioned between the network device and a second network device of the network,
wherein the routing protocol software is to execute a routing protocol to identify a plurality of equal-cost forwarding paths from the first router of the network to the second router of the network;
a path weight calculator of the control unit to, determine that one of the network links is a common network link shared by multiple of the plurality of equal-cost forwarding paths, and, in response to determining that the one of the network links is a common network link shared by multiple of the plurality of equal-cost forwarding paths, compute an amount of bandwidth that can be sent on each of a plurality of outgoing interfaces of the first router for the plurality of equal-cost forwarding paths, wherein computing the amount of bandwidth comprises computing the amount of bandwidth to account for splitting of link bandwidth of the common network link across the multiple equal-cost forwarding paths that share the common network link;
a multipath forwarding component of the control unit to selectively assign packet flows to each of the plurality of outgoing interfaces of the network device based at least on the computed amount of bandwidth;
and
one or more interface cards to receive packets for the packet flows,
wherein the multipath forwarding component forwards packets of each of the packets flows to the respective one of the plurality of outgoing interfaces to which the packet flow is assigned.

5 more elements

Dependencies are inferred from the claim text.