The end users of CRISIS project made it clear that voice communication was a key requirement for the final training system. The primary reason being that trainee communications needed to be made available for analysis during after action review. For that reason, I was required to develop a bespoke voice communication tool. It was developed in C# using the .NET framework, and made use of socket connections for the voice data, a Restful service client for storing the data, an ActiveMQ producer for sending real-time events, and a WCF service for receiving push-to-talk events. The images below show the client and server interfaces, and the tool being used by Icelandic airport emergency response teams during a training event in June, held at Reykjavik airport. The tool has also been deployed to the Portuguese airport authority, based at Lisbon airport, and British Transport Police, based in London.