Are UDP messages atomic?

Question

If I send some sequence of bytes on a UDP socket (ie, in a single send call), is it possible that the receiving socket will receive only part of the transmitted message (ignoring the case of too small a buffer). Or will the byte sequence be delivered in its entirety or not at all, but never partially or in multiple groups?

Answer 1

Yes. UDP datagrams are delivered entire and intact or not at all.