gets the offset of the data stored in this datagram packet . concode_field_sep byte[] data concode_elem_sep int offset concode_elem_sep int length concode_elem_sep ServiceID serviceID concode_elem_sep int capacity concode_elem_sep InetAddress address concode_field_sep void setServiceID concode_elem_sep ServiceID getServiceID concode_elem_sep void setLengthOnly concode_elem_sep void setLength concode_elem_sep void setAddress concode_elem_sep void setData concode_elem_sep void setData concode_elem_sep SocketAddress getSocketAddress concode_elem_sep int getLength concode_elem_sep InetAddress getAddress concode_elem_sep void setSocketAddress concode_elem_sep byte[] getData concode_elem_sep int getCapacity