GPON Key Consistency Detection via OLT-ONU Feedback
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Solution Overview
Problem
Inconsistent keys between an Optical Line Terminal (OLT) and an Optical Network Unit (ONU) in a Gigabit Passive Optical Network (GPON) can lead to decryption failures and service exceptions, which are not addressed by existing standards like ITU-T G.984.x.
Innovation Solution
A method for detecting key consistency between OLT and ONU involves sending a current key information request message, receiving and comparing key information, and performing corresponding processing based on consistency or inconsistency, with options for initiating detection during key switch-over, maintenance, or routine checks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the OLT sends Key_switching time message to the ONU during key switch-over, then the ONU can learn the key switch-over frame number, but the acknowledgement message from the ONU may be lost causing key inconsistency between OLT and ONU
Solution Approach 1:
The patent implements a feedback mechanism where the OLT sends a detection message to the ONU and waits for an acknowledgement. The ONU responds with its current key information, allowing the OLT to verify whether the key switch-over was successfully synchronized. This feedback loop enables the OLT to detect key inconsistencies and trigger appropriate handling procedures.
Solution Approach 2:
The patent performs preliminary key consistency detection before actual data transmission occurs. By detecting key consistency proactively through the detection message and comparison mechanism, the system prevents decryption failures before they happen, rather than waiting for errors to manifest during data communication.
2Reliability
If no key detection mechanism is implemented to reduce system complexity, then the system is simpler to operate, but key inconsistencies cannot be detected leading to service exceptions
Solution Approach 1:
The ONU autonomously provides its current key information in response to the OLT's detection message. The system uses existing message structures and registration mechanisms, allowing the detection functionality to be implemented without adding complex external monitoring equipment or sophisticated detection algorithms. The ONU essentially serves itself by providing the necessary key information when queried.
Solution Approach 2:
The patent utilizes existing message structures (PLOAM messages, registration mechanisms) for multiple purposes - both for normal operations and for key consistency detection. The detection message and response mechanism can be integrated into existing communication protocols, avoiding the need for separate dedicated detection systems and reducing overall complexity.
3Reliability
If frequent key consistency detection is performed to ensure reliability, then key inconsistencies are detected timely, but network overhead and processing time increase
Solution Approach 1:
The patent implements periodic key consistency detection where the OLT sends detection messages at predetermined time intervals rather than continuously or after every key switch-over event. This periodic approach balances the need for reliable detection with the constraint of minimizing network overhead and processing time, allowing the system to detect inconsistencies timely without excessive resource consumption.
Data Source
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AI summary
A method for detecting keys in a gigabit passive optical network, used for detecting consistency between current keys of an OLT and an ONU in a GPON system, comprises the steps of: (a) the OLT sending a current key request message to the ONU, and waiting for the ONU to return current key response messages; (b) if the ONU receives the current key request message, reading the current key stored locally in the ONU, and loading the read content into the current key response messages and sending the response messages to the OLT; (c) if the OLT receives the current key response messages in a predetermined period, acquiring the current key of the ONU from the response messages, and comparing it with the current key stored locally in the OLT, and according to a result of the comparison, performing corresponding processing. The present invention triggers the detection of the consistency between current keys of an OLT and an ONU in various ways, and a latent exceptional situation can be timely discovered and handled, thus the risk of a GPON service exception can be reduced. The present invention fills a gap of ITU-T G.984.x in this respect.