Internet Protocol 



As defined by the [IETF], IP is a protocol for inter-networking between networks using different underlying media. 



IP has two versions in common use: 

* [IPv4] is the most common, and has been in widespread use since the 1980's. 

* [IPv6] is more recent, and does not yet have wide deployment globally, although some countries (ie. Korea, Japan) use it heavily. IPv6 is likely to form the basis for 3G mobile phone networks.