Precision Time Protocol

About: Precision Time Protocol is a research topic. Over the lifetime, 604 publications have been published within this topic receiving 6006 citations. The topic is also known as: PTP & IEEE 1588.

Time synchronization method and time synchronization device

Abstract: The invention discloses a time synchronization method and a time synchronization device. The time synchronization method includes that home terminal equipment enables a PTP (precision time protocol) function for aggregation ports, active ports are selected from physical member ports of the aggregation ports, and the PTP function is configured for the active ports; role information is exchanged between the home terminal equipment and PTP opposite terminal equipment, and the active ports are configured by the aid of the determined role information; the home terminal equipment performs time synchronization via the active ports and active ports of the opposite terminal equipment. The time synchronization method and the time synchronization device have the advantages that time synchronization on the basis of the aggregation ports is implemented, and time synchronization between the home terminal equipment and the opposite terminal equipment is implemented; the PTP function is directly enabled on the aggregation ports, so that configuration is simplified for users, consumption of equipment resources is reduced, the performance of the equipment is improved, and the network topology stability is enhanced.

Secure precision time protocol in packet switched networks

Abstract: IEEE 1588-2008 protocol is used to provide time and frequency synchronization in network. As time and frequency distribution protocols are becoming increasingly common and widely deployed across the networks, concern about their exposure to security threats and vulnerabilities are increasing. One can use external security mechanisms like IPSEC or MACSEC to safe-guard network from various attacks and not specific to timing protocols. To address security related threats IEEE 1588-2019 draft standard D1.5 defines a “PTP integrated security(PTPIS)” mechanism which is complex and not completely integrated because key management mechanism is left open. A simple and “ Fully PTP Integrated Security(FPTPIS)” mechanism which includes key management is proposed by introducing a new general message and TLV. This paper describes how new general message and TLV enables “fully PTPIS” and thus solving the security requirements of the RFC7384.

Model-Based evaluation and improvement of PTP syntonisation accuracy in packet-switched backhaul networks for mobile applications

Abstract: Base stations in mobile networks have very strict frequency synchronisation (also referred to as syntonisation) requirements. As backhaul networks are migrated to asynchronous packet-switching technology, timing over packet using the IEEE 1588 Precision Time Protocol (PTP) replaces current synchronisation methods that rely on the synchronous bit clock of the network. With PTP, base-station clocks derive their frequency from the inter-packet delays of Sync messages sent by a high-quality time source at regular time intervals. Packet-delay variation (PDV) thus has a major impact on the achievable synchronisation quality, and the amount of PDV of a backhaul network determines whether the network can support frequency synchronisation of base stations. We present a simulation and an analytical approach to assessing the suitability of backhaul networks for clock synchronisation using PTP and derive two methods for reducing PDV.

A delay control method in the passive optical network, an optical line terminal and a passive optical network

Abstract: A delay control method in the passive optical network, an optical line terminal and a passive optical network are provided. The delay control method in the passive optical network transmits the precision time protocol message in the direction of downlink, and the method includes: obtaining the buffer time of the precision time protocol message sent to the optical network unit (21); storing the precision time protocol message sent to the optical network unit, when the storing time being equal to the buffer time, sending the precision time protocol message to the optical network unit (22).