US 8,804,501 B2Granted

Link failure recovery method and apparatus

AssigneeTelefonaktiebolaget L M Ericsson (publ)

InventorsAndras Csaszar, Gabor Enyedi

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Abstract

A method of routing packets across a packet switched network domain, comprising a multiplicity of nodes. Each node comprises an ingress interface and an egress interface. For each destination node a default and a detour branching are defined, each specifying a route to the destination node. For each two-edge connected node the default and detour branchings do not share a common ingress interface. Each node operates as an intermediate node receiving a packet at an ingress interface, identifying an egress interface based upon the ingress interface upon which the packet is received and the packet destination, forwarding the packet via that egress interface if the connected link is available and, if the connected link is not available, forwarding the packet via an alternative egress interface associated with said detour branching if the packet was received at an ingress interface associated with said default branching or dropping the packet if the packet was received at an ingress interface associated with said detour branching.

Claims13

Dependent claims

A method of routing packets across a packet switched network domain, the network domain comprising a plurality of nodes, wherein the plurality of nodes includes a source node, a destination node, and one or more intermediate nodes, and wherein each node in the plurality of nodes comprises at least one ingress interface and at least one egress interface, the method comprising:

for the destination node, defining a default branching and a detour branching, each of which specifies a route from each node other than the destination node to the destination node;
and
performing the following at each node operating as an intermediate node for a packet flow being sent from the source node to the destination node, wherein each intermediate node in said plurality of nodes is a two-edge connected node in which the default branching and the detour branching do not share a common ingress interface, and wherein each two-edge connected node is connected to at least two adjacent nodes via a plurality of communication links:
receiving a packet at an ingress interface, wherein the packet is sent to a packet destination,
identifying an egress interface based solely upon the ingress interface upon which the packet is received and the packet destination, without a requirement for a routing flag,
forwarding the packet via the identified egress interface if a connected link connecting the intermediate node to an adjacent node coupled to the identified egress interface is available,
if the connected link is not available, rerouting the packet via an alternative egress interface associated with the detour branching if the packet was received at an ingress interface associated with the default branching, and
if the connected link is not available, dropping the packet if the packet was received at an ingress interface associated with the detour branching.

5 more elements

An intermediate node for use in routing packets across a packet switched network domain that contains a plurality of nodes, wherein the plurality of nodes includes a source node, a destination node, and one or more intermediate nodes, wherein a default branching and a detour branching are defined across the network domain for the destination node, wherein each of the default branching and the detour branching specifies a route from each node other than the destination node to the destination node, and wherein each intermediate node comprises at least two ingress interfaces and at least two egress interfaces, wherein each intermediate node is configured to perform the following for a packet flow being sent from the source node to the destination node:

receive a packet at an ingress interface, wherein the packet is sent to a packet destination, and wherein each intermediate node is a two-edge connected node in which the default branching and the detour branching do not share a common ingress interface, and wherein each two-edge connected node is connected to at least two adjacent nodes via a plurality of communication links;
identify an egress interface based solely upon the ingress interface upon which the packet is received and the packet destination, without a requirement for a routing flag;
forward the packet via the identified egress interface if a connected link connecting the intermediate node to an adjacent node coupled to the identified egress interface is available;
if the connected link is not available, reroute the packet via an alternative egress interface associated with the detour branching if the packet was received at an ingress interface associated with the default branching;
and
if the connected link is not available, dropping the packet if the packet was received at an ingress interface associated with the detour branching.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/669,442Filed 16 Jul 2007
Published: US 2010/0189113 A129 Jul 2010
Granted: 12 Aug 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

H04L 45/22
Routing or path finding of packets in data switching networks: alternate routing
H04L 41/0654
Management of faults, events, alarms or notifications: using network fault recovery
H04L 45/18
Routing or path finding of packets in data switching networks: loop-free operations
H04L 45/28
Routing or path finding of packets in data switching networks: using route fault recovery