UDP disadvantages
Lots of possible intrusions
When a socket is receiving data on a UDP port, it will receive packets sent
to it by any host, whether it is participating in the application or not
This possibility can present a security problem for some applications that
do not robustly distinguish between expected and unexpected packets
Blocking of UDP by your local net administrator
For this reason, many network firewall administrators block UDP data from
being sent to a protected host from outside the security perimeter