If I'm correct, "ping" sents a requests via UDP and simply counts the time until it gets an Ack message. After 16 seconds, I suppose it just gives up.
If ping receives server name instead of ip, it should firstly resolve the name...
So before actual ICMP packet the NBNS is sent, asking what is the IP of the server
If no response is received during the timeout then message is printed that the host is unknown
If the host ip is resolved sucessully but it does not respons to the ICMP request the timeout message is printed (4 times by default)