Data Answer Routing Table for ICN Scalability

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Solution Overview

Problem

Current information-centric networks (ICNs) face inefficiencies due to the large size of Pending Interest Tables (PITs) in routers, which grow significantly with the number of interests handled, leading to increased network load and potential undetected interest loops, as they rely on reverse-path forwarding and PITs for content retrieval.

Innovation Solution

The implementation of a Data Answer Routing Table (DART) in routers, which replaces PITs, using destination-and-return tokens (darts) and nonces to enable correct forwarding of interests and data objects without disclosing the source, allowing for multipath routing and reducing the need for reverse-path forwarding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PITs are used to track individual interests for content retrieval, then content delivery accuracy is improved, but network load increases and scalability deteriorates

Engineering Contradiction:
Improvecontent delivery accuracyVSAvoidnetwork load
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent segments the PIT functionality into two separate components: FIB (Forwarding Information Base) for routing decisions and DART (Data Answer Routing Table) for tracking data delivery. This segmentation allows the system to maintain accurate content delivery tracking while reducing the overall network load by distributing the tracking function across multiple specialized tables rather than a single large PIT.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the interest tracking function from the traditional PIT and relocates it to the DART, which is specifically designed to track data answers rather than interests. This extraction allows the FIB to focus solely on routing decisions, reducing the complexity and network load associated with maintaining a comprehensive PIT for every interest packet.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If PITs are used to store interest state for every interest packet, then content retrieval reliability is improved, but device complexity increases

Engineering Contradiction:
Improvecontent retrieval reliabilityVSAvoidrouter state management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the router's forwarding state into three distinct tables: FIB for routing prefixes to next-hops, DART for tracking data answers to interests, and PIT for maintaining interest state. This segmentation reduces device complexity by allowing each table to be optimized for its specific function, avoiding the need to manage a single complex PIT that handles all state information.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent inverts the traditional approach by having the DART track data answers rather than having the PIT track interests. This inversion simplifies router state management because data answers follow predictable reverse paths, making the tracking function simpler and more efficient compared to tracking the diverse and unpredictable interest packets.

Inventive Principle:
Principle #13The other way round (Inversion)

3Reliability

If reverse-path forwarding is used for content delivery, then content retrieval accuracy is improved, but network efficiency deteriorates

Engineering Contradiction:
Improvecontent retrieval accuracyVSAvoidnetwork efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by having routers pre-establish forward paths for data answers using the DART before actual content delivery is needed. The DART is populated with routing information in advance, allowing data answers to be forwarded efficiently along pre-determined paths rather than requiring complex reverse-path calculations at the moment of delivery, thus improving network efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces the DART as an intermediary between the FIB and the actual data delivery process. The DART mediates by storing pre-computed routing information for data answers, allowing the system to maintain content retrieval accuracy while improving network efficiency by avoiding repeated reverse-path calculations and enabling more direct forwarding paths.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If PIT size grows with the number of interests handled, then content tracking completeness is improved, but scalability deteriorates

Engineering Contradiction:
Improvecontent tracking completenessVSAvoidnetwork scalability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent segments the content tracking function into DART for data answer tracking and FIB for routing, with each table scaled independently. This segmentation allows the system to maintain complete content tracking as network size grows, because each segmented table can be optimized and scaled according to its specific requirements rather than being constrained by a single growing PIT.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent makes the DART a universal table that handles all data answer tracking across the network, regardless of the number or type of interests. This multi-functional approach improves scalability because the DART can efficiently track data answers for any interest without requiring proportional increases in PIT size, allowing the network to scale while maintaining complete content tracking.

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

Data Source

PatentEP3148128B1Information-centric networking with small multi-path or single-path forwarding state
Publication Date: 2019.05.08 CISCO TECHNOLOGY INC
  • EP3148128B1 patent drawingFigure 1
  • EP3148128B1 patent drawingFigure 2
  • EP3148128B1 patent drawingFigure 3

AI summary

One embodiment of the present invention provides a router in an information-centric network (ICN). The router includes a receiving module configured to receive an interest for a piece of content. The interest indicates a name associated with the piece of content. The router further includes an interest-processing module configured to: determine whether the interest can be forwarded; in response to determining that the interest can be forwarded to a second router, obtain a label that is specific to the second router; and attach the label to the interest. The router also includes a forwarding module configured to forward the interest to the second router with the attached label.