Init UAVCAN and change ID

When I use function for set id, like

_node = setNodeID(123);

I see next id in terminal: 268522875x (dec) or 1001557Bh (hex)
Last 7B it is my 123 id which I passed to function.
What means 100155 in the id?
and one more question. How can I transmit to basic message? for example 4 bytes like 0x01,0x02,0x03,0x04

UAVCAN Specification, section 4.2.1:

This is not possible by design. UAVCAN is a strongly typed protocol where communication is modeled in terms of data types, not raw byte strings. You have to define a data type (or use an existing one) to exchange data over the network.