Content Centric Network Interest Timeout Handling via Notification

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Solution Overview

Problem

In content-centric networks (CCN), Pending Interest Table (PIT) entries often time out due to network congestion or computationally intensive tasks, leading to repeated re-expression of Interests and increased network traffic, causing congestion.

Innovation Solution

A content producing device sends a notification message to a content requesting device with an estimate of the additional time needed to generate a Content Object, allowing the requesting device to delay re-sending the Interest, keeping the first Interest alive and reducing PIT entry timeouts by using a new name for the second Interest.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the content producing device performs computationally intensive tasks before sending the Content Object, then the content quality and completeness are improved, but the PIT entry timeout occurs and network congestion increases

Engineering Contradiction:
Improvecontent qualityVSAvoidPIT entry timeout
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The system performs preliminary actions by having the content producing device send a notification message to the content requesting device indicating the additional time needed before the Content Object is ready. This allows the requesting device to delay re-sending the Interest packet, preventing PIT entry timeout while the content is being prepared. The notification message includes a timeout value that tells the requesting device how long to wait before re-expressing the Interest.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the Interest is re-expressed repeatedly after PIT entry timeout, then the content delivery is ensured, but the network traffic increases and congestion worsens

Engineering Contradiction:
Improvecontent deliveryVSAvoidnetwork traffic
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The content producing device provides feedback to the content requesting device by sending a notification message that includes information about the additional time needed to generate the Content Object. This feedback mechanism allows the requesting device to adjust its re-expression timing accordingly, ensuring reliable content delivery while minimizing unnecessary network traffic from premature re-expressions.

Inventive Principle:
Principle #23Feedback

3Quantity of substance

If the PIT entry timeout value is set to a longer duration, then the network traffic is reduced, but the content delivery reliability decreases when computation is intensive

Engineering Contradiction:
Improvenetwork trafficVSAvoidcontent delivery
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The system implements dynamic timeout management where the timeout value is not fixed but is instead communicated dynamically through the notification message from the content producing device to the content requesting device. The requesting device adjusts its re-expression timing based on the actual computation time needed, allowing the timeout duration to adapt to the specific content preparation requirements rather than using a static timeout value.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2975826B1Method and system for keeping interest alive in a content centric network
Publication Date: 2020.02.12 CISCO TECHNOLOGY INC
  • EP2975826B1 patent drawingFigure 1
  • EP2975826B1 patent drawingFigure 2
  • EP2975826B1 patent drawingFigure 3

AI summary

One embodiment provides a system that facilitates a content requesting device to handle a potential timeout event. During operation, the system receives, by a content producing device, a packet that corresponds to a first Interest message from a content requesting device, where the first Interest includes a name. Responsive to determining that additional time is required to generate a matching Content Object for the first Interest, the system generates a notification message which indicates a time period after which a second Interest is to be sent out by the content requesting device. The name for the second Interest can be the same as the name for the first Interest or a new name as indicated in the notification message. The system transmits the notification message to the content requesting device, thereby facilitating the content requesting device to handle a potential timeout event.