What is the result when the NTP network timing server encounters PTP clock synchronization?

When the NTP network timing server encounters PTP clock synchronization, what is the result?
When the NTP network timing server encounters PTP clock synchronization, what is the result?
Network Time Protocol (NTP) is a time synchronization protocol that serves computer clocks over the Internet. It provides a synchronization time mechanism that can adjust time distribution in a large, complex and diverse Internet.
PTP (Precision Time Protocol) is a time synchronization protocol. It is only used for high-precision time synchronization between devices, but it can also be used between devices. frequency synchronization. Compared with various existing time synchronization mechanisms, PTP has the following advantages:
Compared with NTP (Network Time Protocol, Network Time Protocol), PTP can meet higher-precision time synchronization requirements: NTP Generally, time synchronization accuracy can only be achieved at sub-second level, while PTP can achieve sub-microsecond level.
1. Why should we build a precise time synchronization system?
　　New information infrastructure represented by 5G, industrial Internet, satellite Internet, etc., communication signal carrier frequency Stability, uplink and downlink time slot calibration, and reliable transmission all require precise time synchronization control.
　　Industry applications have strict requirements for low latency, low jitter, and low packet loss rate, and the quality requirements for precise time synchronization will also become increasingly higher. Network frequency hopping, resource allocation, routing and forwarding, and data fusion in the industrial Internet all rely on time synchronization applications, otherwise they cannot operate normally. In particular, the time-sensitive industrial Internet has higher requirements for maintaining end-to-end time accuracy on the device, even reaching the nanosecond level.
　　For satellite Internet and low-orbit satellites, only by achieving precise time synchronization with each other can high-speed satellite communications be provided for the coverage area. In addition, in integrated infrastructure such as smart grids, smart mines, and smart roads, as well as major scientific and technological infrastructure, system control, equipment execution, operation statistics, exception handling, etc. all need to have unified time standards, otherwise they will not operate normally.
2. Network time synchronization technology (NTP/PTP)
　　NTP is a standard network time protocol used for time synchronization on the Internet. Its function is to synchronize time within the network. Computer time is synchronized to Coordinated Universal Time (UTC). NTP usually adopts the client/server master-slave working mode to achieve time synchronization through data packet interaction. NTP has a complete algorithm system, which comprehensively uses time filtering, time selection, clustering, clock adjustment and other algorithms to adjust the local system time and frequency. The stability of time synchronization can be guaranteed. It is one of the most widely used network time synchronization technologies at present.
　　Traditional NTP technology uses software timestamps, and the timestamp precision and accuracy are low. Therefore, the synchronization accuracy is generally millisecond level. It is mainly used for network equipment, application servers and applications that do not require high synchronization accuracy. Computer terminals, etc. provide time synchronization services.
　　PTP is a precision time synchronization protocol (PTP) for network measurement and control systems. The currently widely used version is IEEE1588-2008 (1588v2). PTP adopts the master-slave clock synchronization method. The master-slave clock achieves time or frequency synchronization through exchange of synchronization, status and delay measurement messages. PTP supports end-to-end (E2E) and point-to-point (P2P) delay measurement mechanisms, multicast and unicast communication methods, one-step and two-step working modes, and multiple message encapsulation methods such as UDP/IP and IEEE 802.3. At the same time Supports clock models such as ordinary clock (OC), boundary clock (BC) and transparent clock (TC), has a complete clock hierarchy and port status decision algorithm (BMC, best master clock algorithm), and is based on flexible combinations of various working modes It can meet the needs of networking applications in different network environments.
　　PTP uses hardware timestamps. The timestamps have higher precision and accuracy. They can generally achieve nanosecond-level or even higher synchronization accuracy. They are widely used in communication transmission networks, mobile backhaul networks, In high-precision time synchronization solutions for smart grids, high-speed railways and other systems.
　　1588 ATR (1588 Adaptive Time Recovery) is an adaptive time recovery algorithm based on PTP. It establishes clock links in the form of Layer 3 unicast messages between routers. Then, through the interaction of PTP messages, time synchronization between devices across the third-party network is achieved. 1588 ATR is based on 1588v2 to achieve time synchronization across third-party networks that do not support 1588v2 protocol devices. This solves the original problem of using the 1588v2 method to synchronize time, which requires all network devices to support the 1588v2 protocol hop by hop. 1588 ATR is used to synchronize time across devices that do not support the 1588v2 protocol. 1588ATR is a supplement to hop-by-hop support, but it is not highly standardized.
3. Satellite reference timing security
　　The precise timing of new infrastructure mainly relies on satellite-based timing systems such as GPS and Beidou. Once the satellite-based timing signal is interfered by external interference or Destruction due to force majeure factors will render the time synchronization system applications in various fields of new infrastructure ineffective. In addition, time cannot be obtained through satellite-based timing in indoor, mine, high electromagnetic environment and other scenarios, which also greatly limits the application and development of new infrastructure. The second is the risk of existing GPS timing equipment.
　　At present, a large number of clock synchronization equipment in my country are mainly based on GPS timing, and the risks of existing GPS timing equipment require high attention. The third is the risk of network transmission protocols. Currently, the high-precision time synchronization transmission protocol mainly used by the IEEE1588V2 protocol and its derivative wireless network protocols can enable a certain number of time synchronization devices to achieve sub-microsecond accuracy.
4. Advanced technology
　　Jingzhun HR series NTP/PTP time server has developed a smart antenna that builds the GNSS receiver into the smart antenna instead of Traditional time server approach. The advantages of moving the GNSS signal receiver component to the smart antenna include: • Jamming/spoofing detection built into the smart antenna's GNSS reception before the corrupted signal reaches the NTP/PTP time server. • Due to the modular design in the smart antenna, a faulty GNSS receiver or a different GNSS receiver can be easily replaced without downtime of the NTP/PTP time server.
• NTP/PTP time server supports dual GNSS antenna ports, allowing GNSS antennas to be physically isolated to receive different GNSS signals from different or the same satellite system.
Summary: Critical infrastructure requires strong synchronization and network security to help ensure Industry 4.0, new infrastructure, time-sensitive network TSN, cloud/EDGE/FOG technology, telecommunications 5G, smart grid, wisdom The city’s long-term IT/IoT/IIoT reliability.