Generating a signaling service message for a message group of a sysplex coupled together using a signaling service includes executing, on a computer, a data transfer application that communicates with a respective partner data transfer application on each member of the message group, the data transfer application comprised of a plurality of interworking modules including an interface module. Generating the message also includes receiving by the interface module a request from one of the other interworking modules that is related to sending the signaling service message; and based on the request, determining by the interface module a type of message for the signaling service message. Based on the type of message, the interface module identifies a corresponding routine of an operating system executing on the computer which will generate the signaling service message; and invoking the corresponding routine which causes the operating system to generate the signaling service message.