Stateless Multicast Routing via Compressed Explicit Route Headers

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Solution Overview

Problem

Current communication systems face challenges in efficiently supporting stateless multicast in packet distribution networks, particularly in maintaining traffic engineering (TE) across multiple domains, where existing solutions often require complex state management and path computations.

Innovation Solution

The implementation of an apparatus and system that utilizes an Explicit Multicast Route (EMR) encoded in packet headers, allowing routers to forward multicast packets based on unicast IP routes and traffic engineering parameters, enabling stateless multicast with QoS guarantees across multiple domains without linear growth in packet size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If stateless multicast is implemented using existing solutions, then multicast forwarding is simplified, but traffic engineering capabilities are lost and complex state management is required

Engineering Contradiction:
Improvemulticast forwarding simplicityVSAvoidstate management complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent segments the multicast routing information into two parts: (1) a compressed representation of the multicast distribution tree stored in the packet header, and (2) the actual forwarding decisions made by routers using their existing unicast routing tables. This segmentation allows stateless multicast to work with standard router infrastructure while maintaining traffic engineering capabilities through the compressed tree representation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary compression algorithm that transforms the multicast distribution tree into a compact format suitable for packet headers. This intermediary representation serves as a bridge between the complex traffic engineering requirements and the simple stateless forwarding mechanism, enabling both objectives to coexist.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If explicit path information is included in packet headers for traffic engineering, then QoS guarantees are improved, but packet size increases linearly with network size

Engineering Contradiction:
ImproveQoS guaranteeVSAvoidpacket size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent changes the parameter representation by using a compressed encoding scheme that represents network paths using fewer bits. Instead of including full explicit path information for each hop, the system uses a compressed tree representation that captures the essential routing structure without the linear overhead, thereby maintaining QoS guarantees while controlling packet size.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent transitions from representing paths in one dimension (sequential hop-by-hop explicit routing information) to another dimension (hierarchical tree structure). This dimensional change allows the representation of complex multicast distributions using a compact hierarchical format rather than linear path descriptions, reducing packet size while preserving traffic engineering capabilities.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If stateless multicast is used across multiple domains, then network scalability is improved, but maintaining traffic engineering across domains becomes difficult

Engineering Contradiction:
Improvemulti-domain scalabilityVSAvoidpath computation complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent creates a universal compressed tree representation that can be used across multiple administrative domains. This representation serves multiple functions: it provides traffic engineering information for path computation, enables stateless forwarding across domain boundaries, and works with existing unicast routing infrastructure. The universality of this representation allows it to function effectively in multi-domain environments without requiring domain-specific modifications.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3958504B1Stateless multicast with traffic engineering
Publication Date: 2024.02.14 NOKIA SOLUTIONS & NETWORKS OY
  • EP3958504B1 patent drawingFigure 1
  • EP3958504B1 patent drawingFigure 2A~2D
  • EP3958504B1 patent drawingFigure 2E~2F

AI summary

Various example embodiments for supporting stateless multicast in communication networks are presented. Various example embodiments for supporting stateless multicast in communication networks may be configured to support stateless multicast in a packet distribution network that supports traffic engineering (TE). Various example embodiments for supporting stateless multicast in a packet distribution network that supports TE may be configured to support stateless multicast in a stateless multicast domain with TE. Various example embodiments for supporting stateless multicast in a stateless multicast domain with TE may be configured to support stateless multicast in a stateless IP multicast domain with TE, which may be referred to herein as a stateless IP multicast TE domain.