Network Device Timing Packet Header Modification for Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing timing synchronization methods across networks, particularly using Precision Timing Protocol (PTP), fail to accurately account for time corrections due to traversing network equipment, leading to potential errors in financial transactions, telecommunications, and video over IP services.
Innovation Solution
A method where network devices modify timing control packets to indicate their synchronized state and the time of packet reception, allowing egress network devices to calculate and include the resident time of the packet on the network, thereby correcting for traversal delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If PTP timing control packets are transmitted across the network without modification, then the network structure remains simple and easy to operate, but timing synchronization accuracy deteriorates due to unaccounted network traversal delays
Solution Approach 1:
The ingress network device performs preliminary actions by modifying the PTP packet header before transmission, inserting its reception timestamp and synchronization state. This preliminary timing information allows the egress device to calculate network traversal delay without complex real-time processing, resolving the contradiction between accuracy and complexity.
Solution Approach 2:
The PTP packet header serves as an intermediary carrier, transporting timing information (reception timestamp, synchronization state) between ingress and egress network devices. This intermediary mechanism enables accurate timing synchronization while keeping individual device processing relatively simple, as each device only needs to read and write specific header fields.
2Reliability
If network devices modify timing control packets to include reception timestamps and synchronized state indicators, then timing synchronization accuracy improves, but the processing complexity and computational overhead increase
Solution Approach 1:
The timing synchronization function is segmented into distinct, simple operations: the ingress device segments the task of recording reception timestamp and setting synchronization state in the packet header, while the egress device segments the task of reading these fields and calculating the time difference. This segmentation improves reliability through clear division of responsibilities while keeping each device's processing complexity low.
3Measurement precision
If the ingress network device records and transmits the exact reception time of the timing control packet, then the measurement precision of timing synchronization improves, but the loss of time information increases due to network traversal delays
Solution Approach 1:
The system implements feedback by having the egress network device use the ingress reception timestamp (embedded in the packet) along with its own reception timestamp to calculate the actual network traversal time. This feedback mechanism compensates for time loss by measuring and accounting for the exact delay experienced by each packet, thereby maintaining high measurement precision despite variable network conditions.
Data Source
AI summary
A network device may receive a timing control packet from a first client device. The network device may determine that the network device is in a synchronized state relative to a network grandmaster clock. The network device may modify a first field of a header of the timing control packet to indicate that the network device is in a synchronized state. The network device may modify a second field of the header of the timing control packet to indicate a time at which the network device received the timing control packet from the first client device. The network device may forward, via the network, the timing control packet toward a second client device.