Fabric Path Forwarding for Virtual Nodes

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Solution Overview

Problem

In packet-based computer networks, internal packet load balancing often results in an increased number of fabric hops, leading to unnecessary bandwidth consumption and inefficiency, especially when routers are partitioned into multiple virtual nodes.

Innovation Solution

The technique involves modifying incoming packets to include a fabric path header that requests fabric path information from a destination packet forwarding engine (PFE), allowing direct forwarding to the egress PFE instead of load balancing, thereby reducing fabric hops and conserving bandwidth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If internal packet load balancing is used to forward packets across the switch fabric, then bandwidth utilization is improved, but the number of fabric hops increases leading to inefficiency

Engineering Contradiction:

Improvebandwidth utilizationVSAvoidnumber of fabric hops

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The system performs preliminary actions by obtaining fabric path information about egress PFEs in advance through path modules. This pre-acquired information is stored and used to make direct forwarding decisions, eliminating the need for load balancing lookups during packet forwarding and reducing fabric hops while maintaining bandwidth efficiency

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A path module acts as an intermediary between PFEs and the switch fabric, providing fabric path information that enables direct packet forwarding. This intermediary component facilitates the transition from load balancing to direct forwarding by mediating the acquisition and distribution of egress PFE path information

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If load balancing is applied to incoming packets, then traffic distribution is improved, but direct paths to egress PFEs are lost resulting in additional fabric hops

Engineering Contradiction:

Improvetraffic distributionVSAvoidfabric path length

Core Design Contradiction:

ProductivityVSLength of moving object

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system changes the forwarding parameter from load-balanced next-hop selection to direct egress PFE targeting. By modifying the forwarding behavior to use pre-obtained fabric path information, packets are directed straight to the egress PFE rather than being distributed through intermediate PFEs, thus shortening the fabric path length

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP3493490B1Optimizing fabric path forwarding for virtual nodes within an electronic device

Publication Date: 2021.12.29 JUNIPER NETWORKS INC

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AI summary

16. The techniques describe directly forwarding a packet from an ingress packet forwarding engine to a particular destination packet forwarding engine (PFE) when internal packet load balancing may otherwise result in an increased number of fabric hops. For example, a source PFE may receive incoming packets destined for a router reachable only by a particular destination PFE (e.g., egress PFE). Rather than load balancing the incoming packets to a destination PFE that is likely to be a non-egress PFE, a source PFE obtains fabric path information associated with the egress PFE from a destination PFE such that source PFE may forward incoming packets directly to the egress PFE.