Clock Synchronization. Production network devices must have internal clocks synchronized to reliable time sources.
Clock Synchronization. Supplier shall ensure that the clocks of all relevant information processing systems within the Supplier's environment have been synchronized with an agreed accurate time source to support tracing and reconstitution of activity timelines.
Clock Synchronization. An important question is how practical the synchrony assumption is, which will be the topic of this section. The synchrony assumption essentially states that all honest replicas’ messages arrive in time. This requires two properties: (i) a bounded message delay and (ii) locked step execution, i.e., honest replicas enter each round roughly at the same time. The second property is important because, if replica i enters a round much earlier than replica j, then i may end up finishing the round too soon without waiting for j’s message to arrive. In our protocol, for example, this could prevent i from detecting leader equivocation and result in a safety violation. The XFT paper provided some justification for the bounded message delay assumption in certain applications [26]. But we still need a mechanism to enforce locked step execution. To this end, we will use the following clock synchronization protocol, which may be interesting outside Byzantine agreement. It is a variation of the clock synchronization protocol by Xxxxx et al. [10]. The key change is to have parties sign independently in parallel (as opposed to sequentially) to facilitate the use of threshold signatures. The protocol will be executed at known time intervals. We call each interval a “day”.
Clock Synchronization. An important question is how practical the synchrony assumption is, which will be the topic of this section. The synchrony assumption essentially states that all honest replicas’ messages arrive in time. This requires two properties: (i) a bounded message delay and (ii) locked step execution, i.e., honest replicas enter each round roughly at the same time. The second property is important because, if replica i enters a round much earlier than replica j, then i may end up finishing the round too soon without waiting for j’s message to arrive. In our protocol, for example, this could prevent i from detecting leader equivocation and result in a safety violation. The XFT paper provided some justification for the bounded message delay assumption in certain applications [26]. But we still need a mechanism to enforce locked step execution. To this end, we will use the following clock synchronization protocol, which may be interesting outside Byzantine agreement. It is a variation of the clock synchronization protocol by Xxxxx et al. [10]. The key change is to have parties sign independently in parallel (as opposed to sequentially) to facilitate the use of threshold signatures. The protocol will be executed at known time intervals. We call each interval a “day”. ⟨ ⟩ Round 0 (sync) When party i’s clock reaches the beginning of day X, it sends a sync, X i message to all parties including itself. ⟨ ⟩ Round 1 (new-day) The first time a party j receives f + 1 sync, X messages from distinct parties (either as f + 1 separate sync messages or within a single new-day message), it • sets its clock to the beginning of day X, and • ⟨ ⟩ sends all other parties a new-day message, which is the concatenation of f + 1 sync, X messages from distinct parties. The above protocol bootstraps lock-step synchrony from the message delay bound ∆ and a clock drift bound. Each sync message is triggered by a party’s own local clock, independent of when day X would start for other parties. The f + 1 sync messages can be replaced with a threshold signature for better efficiency. The protocol refreshes honest parties’ clock difference to at most the message delay bound ∆ at the beginning of each day. The first honest party to start a new day will broadcast a new-day message, which makes all other honest parties start the new day within ∆ time. Obtaining a new-day message also means at least one honest party has sent a valid sync message, ensuring that roughly one day has indeed passed since the ...
Clock Synchronization. Process of precisely coordinating or matching two or more activities, devices, or processes in time.
Clock Synchronization. The real time clocks in all building control panels and workstations shall be synchronized on command of an operator. The system shall also be able to automatically sequence all system clocks, daily from any operator designated device in the system. The system shall automatically adjust for daylight savings and standard time if applicable.
Clock Synchronization. Clocks of all servers provisioned as a part of rendering the Service are synchronized to the primary time source provided by the cloud provider, which hosts the Environment/s used to provide the Service.
