@host' id='query-id'> <query xmlns=`setinfo:iq: 'shelf-2.card-6.link-1. status'/> <var>Offline</var> /query> </iq> </setenvp:Body> </setenvp:setenvp> 4. TRAP message: This message allows the agent to spontaneously inform the manager of an important event. Traps are very effective in sending fault information. The body of the trap message sent by the agent will contain an identifier and the information details on the reason for the generated trap. These XML traps can be collected by the manager and parsed for details that can be used for debugging the error scenario captured by the TRAP message. TRAP message with XML: <trapenvp trapenvp to= 'host' xmlns='trapinfo:client xmlns:trapenvp=`--URI- - --'> <trapenvp:Header <trapenvp:trapenvp 1 from=`host id=`stream-id' xmlns='trapinfo:client' xmlns:trapenvp=`- </trapenvp:Header> <trapenvp:Body> <iq type='trap' to= 'mgr@host' id=`query-id'> <query xmlns='trap:iq:Trunk.ABC.FaultDetected'> <trapenvp:Fault> <faultcode>Fault Code here</faultcode> <faultstring>Fault String here</faultstring> </trapenvp:Fault> </query> </iq> </getenvp:Body> </ getenvp:getenvp > 18.5.2 Transfer of Message The XMLP envelope needs to be packaged with the UDP header with details of source and destination port. Figure 18.2 shows the XMLP envelope with the UDP XML-Based Protocols UDP header XMLP envelope 15 16 16-bit source port 16-bit destination port 16-bit UDP length 16-bit UDP checksum bytes + namespace header XMLP body Data (if any) XMLP envelope header XMLP with UDP binding Figure 18.2 Message for transfer with transport binding. header. This is not enough for transmission over the network. Before transmission to a packet network, the message needs to be appended with an IP header. The IP frame that is to be transmitted will contain an Ethernet header and IP header on the UDP datagram with the XMLP envelope. Transmitting the host information in the IP frame helps to identify the host IP address. Port information should also be available for proper transfer to the specified application in the ho