UDP socket , client side

[zio_mangrovia]

In UDP communication when I send a packet from client I execute the socket() system call but I didn't understand if It's necessary to follow the bind()one too.

client side

Case A:

socket(...)
bind(...)
sendto(...)


Case B:
socket(...)
sendto(...)

It's right A or B or both cases ?
Peraphs if I omit bind() the O.S. automatically executes It ?


Bind links socket to ip address+port, so according my opinion this task should be execute from each client too, because clients in TCP/UDP communication use IP+port. What do you think ?

Thanks