Distributed Domain Assignment in Fiber Channel Fabrics

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Solution Overview

Problem

The increasing scale of storage area networks (SAN) configurations and consolidations lead to domain ID assignment issues due to overlapping domain IDs in different physical infrastructures, causing compatibility problems and adverse effects on inter-VSAN routing.

Innovation Solution

A method and system for providing distributed allowed domains in a fibre channel fabric, where a principal switch determines a domain configuration, retrieves current parameters, generates an updated domain list, and assigns allowed or disallowed domains to subordinate switches, ensuring consistency and preventing conflicts by restricting the range of assignable domains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a principal switch assigns domain IDs to all switches in the fabric, then domain assignment is centralized and manageable, but domain ID conflicts occur when merging fabrics with overlapping domain IDs

Engineering Contradiction:

Improvedomain assignment managementVSAvoiddomain ID uniqueness

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent segments the domain ID assignment process by introducing the concept of 'allowed domain lists' that are distributed to multiple switches rather than centralized in a single principal switch. Each switch maintains its own allowed domain list, enabling distributed validation of domain ID assignments and preventing conflicts during fabric merging.

Inventive Principle:

Principle #1Segmentation

2Device complexity

If domain IDs are assigned dynamically by the principal switch, then addressing complexity is reduced, but compatibility issues arise with interop mode and inter-VSAN routing

Engineering Contradiction:

Improveaddressing complexityVSAvoidinterop compatibility

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by allowing different switches to have different allowed domain lists tailored to their specific requirements. Each switch can configure its own domain restrictions based on interop mode requirements, inter-VSAN routing needs, and fabric-specific policies, rather than applying a uniform domain assignment rule across all switches.

Inventive Principle:

Principle #3Local quality

3Quantity of substance

If the number of switches in SAN networks increases, then network capacity and redundancy improve, but domain ID assignment conflicts increase due to overlapping domains

Engineering Contradiction:

Improvenumber of switchesVSAvoiddomain ID assignment

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent implements feedback mechanisms where switches exchange information about their allowed domain lists through fabric parameter exchanges. This feedback loop enables each switch to validate proposed domain assignments against the collective state of the fabric, preventing domain ID conflicts even as the number of switches and fabrics increases.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS9686187B2Method and system for providing distributed allowed domains in a data network

Publication Date: 2017.06.20 CISCO TECHNOLOGY INC

AI summary

Method and system for providing distributed domains in a fiber channel fabric including determining a domain configuration of a resource, retrieving one or more current domain configuration parameters, determining a list of domains in a fiber channel fabric, and generating an updated domain list for the resource in the fabric is disclosed.