IPv4 addresses are 32-bits long, written in decimal format, and separated by periods.
IPv6 addresses are 128-bits long, written in hexadecimal format, and separated by colons. IPv4 addresses cannot be used as is in IPv6, but IPv6 does support a special class of addresses: the IPv4-mapped address.
In an IPv4-mapped address, the first 80 bits are set to zero, the next 16 bits are set to 1, and the last 32 bits represent the IPv4 address.
IPv4 address IPv4-mapped address (for use in IPv6) 192.0.2.1 ::ffff:192.0.2.1
SDP – Sockets Direct Protocol – Fatest way for connections to transfer data as it is transferred directly from memory rather than going via operating system.
Supported in JDk 1.7 on Solaris and Linux. More details here, http://docs.oracle.com/javase/tutorial/sdp/sockets/index.html
InfiBand details, http://www.infinibandta.org/content/pages.php?pg=technology_overview