This following was reported in the Google group (https://groups.google.com/forum/#!topic/sitewhere/ahm2oX-7MmE):
"I am a MQTT Client that is sending Location update to Sitewhere and then I am using Sitewhere outbound event processor WSO2 CEP, which receiving it as wso2event. So the problem is this wso2 event doesnt contain the deviceHardwareId so I am not able to send the results back to Sitewhere as an alerts on SiteWhere/input/json. Without deviceHardwareId, Sitewhere will not parse the json received correctly. So what should I do to forward those alerts. "
Investigate support for round-trip processing so that WSO2 can post data back into SiteWhere.