SDN Controller EVPN BUM Traffic P-Tunnel Optimization

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Solution Overview

Problem

Existing EVPN solutions face challenges in efficiently handling broadcast, unknown unicast, or multicast (BUM) traffic due to low bandwidth efficiency in ingress replication and high operational complexity and costs associated with P2MP tunnels, which also lack flexibility in traffic engineering.

Innovation Solution

A controlling device, such as an SDN controller, determines a P device to handle BUM traffic on behalf of other PE devices within an EVPN instance, using route reflection and configuration to establish a flexible P-tunnel that optimizes traffic replication without requiring changes to existing PE devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If ingress replication is used to send BUM traffic from a single ingress PE device to other PE devices, then device complexity is reduced, but bandwidth efficiency deteriorates due to low bandwidth utilization

Engineering Contradiction:
ImprovePE device complexityVSAvoidbandwidth efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent introduces a controlling device (SDN controller) as an intermediary that establishes a P2MP tunnel from the ingress PE device to multiple egress PE devices. This intermediary approach allows the ingress PE to send a single copy of BUM traffic that is then efficiently distributed through the controlled tunnel, resolving the contradiction between simple PE device operation and bandwidth efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the traditional mechanical ingress replication mechanism with a software-controlled P2MP tunneling system. Instead of PE devices physically replicating traffic packets, the SDN controller establishes logical tunnel paths that enable efficient traffic distribution, substituting mechanical replication with software-defined routing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Loss of energy

If P2MP tunnels are used to create a multicast tree for BUM traffic, then bandwidth efficiency is improved, but device complexity and operational costs increase due to mandatory end-to-end multicast support and high maintaining costs

Engineering Contradiction:
Improvebandwidth efficiencyVSAvoidoperational complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The SDN controller acts as an intermediary that centralizes the complexity of P2MP tunnel management. Instead of requiring each PE device to independently support and maintain end-to-end multicast functionality, the controlling device establishes and manages the P2MP tunnels, reducing operational complexity at the network edge while maintaining bandwidth efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent extracts the complex multicast tunnel management functionality from the PE devices and relocates it to the SDN controller. This extraction removes the burden of end-to-end multicast support from edge devices, simplifying their operation while preserving the bandwidth efficiency benefits of P2MP tunneling.

Inventive Principle:
Principle #2Taking out (Extraction)

3Loss of energy

If P2MP tunnels with RSVP-TE or mLDP are used to create a multicast tree, then bandwidth efficiency is improved, but ease of operation deteriorates due to heavy tasks in establishing and maintaining multicast trees

Engineering Contradiction:
Improvebandwidth efficiencyVSAvoidease of operation
Core Design Contradiction:
Loss of energyVSEase of operation

Solution Approach 1:

The SDN controller provides self-service functionality by automatically establishing and maintaining P2MP tunnels based on network state and traffic requirements. This eliminates the need for manual configuration and complex operational interventions, allowing the system to self-manage the multicast infrastructure while maintaining bandwidth efficiency.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements feedback mechanisms where the SDN controller continuously monitors network conditions and dynamically adjusts P2MP tunnel configurations. This feedback loop enables automatic optimization of multicast traffic paths, improving ease of operation while maintaining bandwidth efficiency through adaptive resource allocation.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3735763B1Controlling device and method implemented thereon for ethernet virtual private network
Publication Date: 2025.03.05 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3735763B1 patent drawingFigure 1~2
  • EP3735763B1 patent drawingFigure 3
  • EP3735763B1 patent drawingFigure 4

AI summary

A controlling device is disclosed for Ethernet virtual private network (EVPN). According to an embodiment, the controlling device determines a first provider (P) device which is to handle broadcast, unknown unicast or multicast (BUM) traffic from a first provider edge (PE) device in an EVPN instance, on behalf of remaining PE devices in the same EVPN instance. The controlling device performs route reflection from the remaining PE devices to the first PE device such that the first PE device knows that BUM traffic needs to be forwarded to the first P device. The controlling device configures the first P device such that upon receipt of BUM traffic from the first PE device, the first P device can forward the BUM traffic to the remaining PE devices.