Development of a Distributed Alarm System

My teacher spent a job developing an alarm tool, panic button, more or less. Where a computer (client) will trigger the button and another computer (server) will receive the notification and will fire a siren. Only he said he did not want as a client server architecture, he wanted a distributed architecture. I could not understand, is it possible to do this program with this architecture? Can anyone tell me which way to continue using java? Thank you.