Imported from previous forum
What is the best way to inform order originators that a network connection is down to an exchange? In this scenario, the exchange is still open, so TradingSessionStatus is inappropriate. NetworkCounterpartySystemStatusResponse is close in meaning, but in this case, the unreachable party is an exchange rather than a trading counterparty such as a firm or market maker.
It is also ok to send TradingSessionStatus without a change of TradSesStatus(340) if you want to communicate an event that occurred with TradSesEvent(1368). Current values imply that there is always also a change of session or subsession (standard use case) but you can use Reserved100Plus values to convey events such as the one described above.
You RoE should then explain what change in behavior occurs, e.g. that best execution is no longer possible because orders cannot be routed to an away market or that price validation is suspended due to unavailability of reference prices from an away market.
Obviously you need to send a second TradingSessionStatus message when the network is back up again.