Specifies the size of the data portion to be
transmitted in a ping operation in octets. A ping
request is usually an ICMP message encoded
into an IP packet. An IP packet has a maximum size
of 65535 octets. Subtracting the size of the ICMP
or UDP header (both 8 octets) and the size of the IP
header (20 octets) yields a maximum size of 65507
octets.