Voice Traffic Gateway Signalling Filter and Warning Tone
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Communications networks with separate traffic domains face security threats when subscribers with different privileges or security levels initiate calls across domains, potentially establishing covert channels, and there is a need to indicate the security level of the calling party during voice calls.
Innovation Solution
A voice traffic gateway that applies a non-secure warning tone to calls from different domains, using a non-secure warning tone application apparatus and a signalling filter to route and modify voice and signalling messages, while ensuring only authorized communications are allowed, and identifying and managing domain-specific traffic labels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If voice calls are allowed between different traffic domains, then communication connectivity is improved, but security threats increase due to potential covert channels
Solution Approach 1:
A gateway is introduced as an intermediary component between different traffic domains. The gateway includes a signalling filter that intercepts and examines signalling messages, comparing features against reference values to detect and block covert communication channels while allowing legitimate calls to pass through.
Solution Approach 2:
The system implements feedback by applying a non-secure warning tone to voice calls originating from different traffic domains. This feedback mechanism alerts the receiving party about the security status of the calling party, enabling informed communication decisions.
2Object-affected harmful factors
If signalling messages are filtered to prevent covert channels, then security is improved, but call establishment may be blocked
Solution Approach 1:
The signalling filter applies selective filtering by comparing specific features of signalling messages against reference features. Only messages with matching features are blocked, while legitimate messages pass through unaffected. This localized filtering approach prevents covert channels without disrupting normal call establishment.
3Loss of information
If a non-secure warning tone is applied to voice calls, then user awareness of security status is improved, but voice message quality deteriorates
Solution Approach 1:
The non-secure warning tone is applied periodically rather than continuously throughout the voice call. This periodic application provides sufficient security awareness to the user while minimizing the impact on overall voice message quality and intelligibility.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A voice traffic gateway (10) comprising a voice traffic input (12), a voice traffic output (14), a first domain router (16), non-secure warning (NSW) tone application apparatus (18) and a signalling filter (20). The input (12) receives voice traffic comprising voice messages and signalling messages from a first traffic domain. The output (14) delivers output voice messages and signalling messages to a second, different traffic domain. The first domain router (16) routes voice messages to the NSW apparatus (18) and routes signalling messages to the signalling filter (20). The NSW apparatus (18) applies a NSW tone to a received voice message to form an output voice message. The signalling filter (20) compares a feature of a received signalling message with a reference feature. The signalling filter (20) will pass a signalling message if the signalling message feature is the same as the reference feature and will block a signalling message if the signalling message feature is not the same as the reference feature.