Periodic Refresh

The CFE Multicast TOP feed will periodically broadcast un-sequenced Futures Instrument Definition, Price Limits, and Market Snapshot messages that participants can use to recover from gaps or that may be used by late joiners to obtain a current state of the top of book for each Symbol. Un-sequenced messages are sent in a continuous loop. The Price Limits and Market Snapshot messages complete their loop approximately once every 3 seconds. The Futures Instrument Definition message completes its loop once a minute.

Participants that are not latency sensitive can use the Periodic Refresh mechanism as a substitute for the sequenced, real-time TOP messages. These participants would process only the un-sequenced Futures Instrument Definition, Price Limits, and Market Snapshot messages to get a periodic view of the top of book quote and volume for each Symbol.