It doesn't matter, with the way IP works any reliable datagram protocol would contain an implementation of 90% of TCP. The more fragmented an IP packet gets al

It doesn't matter, with the way IP works any reliable datagram protocol would contain an implementation of 90% of TCP. The more fragmented an IP packet gets along the way the less likely it is it will reach destination, so you have to take into account path MTU size and split your datagrams accordingly. You also want to send as many datagrams as you have available in as few IP packets as possible and you want to do slow start for the same reasons TCP does it. Result: your datagrams need to become a stream of bytes to be handled efficiently by any transport protocol sitting on top of IP.