PBBN Backbone Core Bridge MAC Address Visibility Reduction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In data centers, the increasing number of servers exceeds the capacity of bridge filtering databases, leading to unnecessary flooding of data frames and degradation of network performance due to the inability of bridges to learn all Media Access Control (MAC) addresses.

Innovation Solution

Implementing a Provider Backbone Bridged Network (PBBN) configuration with backbone core bridges and edge bridges that learn MAC addresses at the core but not at the edge, using C-tagged service interfaces and Encapsulated Address Types to reduce the number of visible MAC addresses and prevent flooding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If bridges learn all MAC addresses of servers in the network, then forwarding precision is improved, but bridge FDB capacity is exceeded leading to flooding

Engineering Contradiction:

Improveforwarding precisionVSAvoidFDB capacity

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent segments the network into customer bridged networks (CBNs) and provider backbone bridged network (PBBN). Edge bridges learn MAC addresses within CBNs while core bridges in PBBN learn only aggregate MAC addresses of edge bridges, dividing the learning responsibility and preventing FDB exhaustion at core bridges.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Edge bridges act as intermediaries between customer networks and the provider backbone. They learn and maintain FDBs for customer MAC addresses, while core bridges only need to learn MAC addresses of edge bridges, using the edge bridge as a mediator to avoid direct learning of all customer MAC addresses.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If bridges flood frames with unknown destination addresses, then delivery reliability is improved, but network traffic increases and performance degrades

Engineering Contradiction:

Improvedelivery reliabilityVSAvoidnetwork performance

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent segments the broadcast domain into multiple isolated CBNs using PBBN. Frames are flooded only within the local CBN where the destination MAC address resides, rather than flooding across the entire network, maintaining reliable delivery while reducing unnecessary traffic.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each CBN has localized frame flooding confined to its own domain. Edge bridges perform local flooding within their attached CBNs for unknown MAC addresses, while core bridges do not flood frames unnecessarily, applying different flooding behaviors to different network regions based on local conditions.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS8549178B2Using provider backbone bridged network to reduce the number of media access control addresses visible to core bridges in the data center

Publication Date: 2013.10.01 FUTUREWEI TECHNOLOGIES INC

AI summary

A system comprising a backbone core bridge (BCB) in a provider backbone bridged network (PBBN), and a backbone edge bridge (BEB) coupled to the BCB via a provider network port (PNP) and to a customer bridge in a customer bridged network via a C-tagged service interface, wherein the C-tagged service interface maps a service instance from the customer bridged network that is identified by a customer-virtual local area network identifier (C-VID) to a backbone service instance on the PBBN that is identified by a service instance identifier (I-SID).