4.1 ECHO_REQUEST_PDU

The following is an annotated dump of an ECHO_REQUEST_PDU message (section 2.2.1).

 00000000 48 65 6c 6c 6f 20 77 6f 72 6c 64 21                 Hello world!
  
 48 65 6c 6c 6f 20 77 6f 72 6c 64 21 -> ECHO_REQUEST_PDU::echoRequest