When Vonage receives an SMS message on a Vonage number, it looks up the webhook endpoint associated with that number and calls it with a big blob of JSON describing the message that was just received. To handle this, we use Ngrok to tunnel incoming requests from Vonage's servers to our local machine, where Jetty is running. We configure Jetty to run on port 8080 by default, which makes life easier. A small servlet written in Java receives and processes the JSON data sent by Vonage, printing it to the console for debugging purposes. The servlet is then configured with a URL pattern of /inbound to receive the webhook calls from Vonage. Once configured, sending an SMS message to the number should trigger the servlet to print the received parameters to the console.