Distance-Based Interest Forwarding in Content-Centric Networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing content-centric network (CCN) forwarding strategies fail to safely route Interests and detect loops, especially when Interests are aggregated or forwarded over multiple paths, leading to potential long-term routing loops and undetected Interest loops due to reliance on nonces for unique identification.
Innovation Solution
Implementing a distance-based Interest forwarding strategy, Strategy for Interest Forwarding and Aggregation with Hop-counts (SIFAH), where each CCN router stores next hops and hop counts in the Forwarding Information Base (FIB), and includes a hop count in forwarded Interests to determine if an Interest loop occurs by comparing the hop count in the received Interest with the router's hop count to the content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If CCN routers aggregate Interests to reduce unnecessary traffic, then network traffic efficiency is improved, but detection of Interest loops becomes difficult
Solution Approach 1:
The patent introduces hop count as an intermediary parameter that mediates between Interest aggregation and loop detection. Each Interest packet carries a hop count value that is decremented at each router, allowing loop detection without requiring routers to track individual Interest identities through aggregation. This intermediary mechanism enables both traffic reduction through aggregation and reliable loop detection.
Solution Approach 2:
The patent changes the parameter used for loop detection from Interest identity (nonce) to hop count. By transforming the detection mechanism to rely on a numerical parameter that is easily modifiable during packet traversal, the system can detect loops even when multiple Interests are aggregated together, as the hop count parameter is independent of Interest identity.
2Device complexity
If CCN routers use nonces for unique Interest identification, then Interest tracking is simplified, but loop detection fails when Interests are aggregated
Solution Approach 1:
The hop count acts as an intermediary that bridges the gap between simple Interest tracking and reliable loop detection. While nonces provide unique identification for tracking purposes, the hop count provides a separate, aggregation-independent mechanism for loop detection, ensuring reliability even when multiple Interests are combined.
Solution Approach 2:
The patent segments the Interest packet into distinct functional components: the nonce for identification and tracking, and the hop count for loop detection. This segmentation allows each component to serve its specific purpose independently, with the hop count remaining valid and useful even when Interests are aggregated and nonces are combined.
3Reliability
If distance-based forwarding is implemented with hop count comparison, then Interest loop detection is improved, but additional information storage is required in FIB
Solution Approach 1:
The patent changes the FIB storage requirement from storing complete path information or multiple metric types to storing only a single hop count parameter per destination. This parameter change simplifies the data structure while maintaining effective loop detection capability through comparison with the Interest packet's hop count.
Solution Approach 2:
The patent extracts only the essential element needed for loop detection (hop count) from more complex routing information structures. By taking out just this single numerical parameter from the FIB, the system achieves reliable loop detection without the overhead of storing complete path histories or multiple routing metrics.
Data Source
AI summary
One embodiment of the present invention provides a system for correctly processing an interest in a content-centric network (CCN). During operation, a first node in the CCN receives an interest for a piece of content from a second node. The interest indicates a name of the piece of content and a hop count from the second node to a destination node advertising the piece of content. The system determines, based on forwarding information and information associated with pending interests stored on the first node, whether a distance-based forwarding condition is met; and in response to the distance-based forwarding condition being met, accepts the interest.