I have enabled the trace:
<logging traceSpecification="*=audit=enabled:com.worklight.integration.notification.*=finest=enabled" />
I can see the trace:
com.worklight.integration.notification.gcm.GCMSender 1 sendNoRetry Sending JSON to GCM server: {"collapse_key":"myPush","data":{"alert":"Hay una nueva ficha","payload":"{\n \"alias\": \"myPush\",\n \"identificador\": \"a035\",\n \"nombre\": \"aName35\"\n}","badge":"1"},"registration_ids":["APA91bG03cXkyVM6pA2-CO1g-tZUQL6FwJgugaa68YngIyGbbR_oDzVNn-1RULpoktvMUKwF3D1qK4bx-4OVeAbUzBqNpqO3m_1hwz0Z6I0B_DS_Jvc0wzI_fjKpJ9vqPNO58Bdt40ms"]} [project DemoM]
But I do not know if that trace means that everything has gone ok and the message is now in the GCM servers.
I have also enabled sniffers (WireShark in Mac and SmartSniff in XP) in dev server and stand alone server but I have not been able to detect any pattern. Everything is under https so I only see some traces for google hosts but I can not take any conclusions. Although it is valid to see a trace for google gcm immediately after the server trace that takes less than 500ms
Anyway now it is taking time to the notification to arrive in both servers so I guess everything is working fine in the worklight side.