IPv4 hasstood the test of scaling an Internet work to a global utility, the size of theInternet today. But IPv4 wasn't initially designed to support a high number ofnetwork equipment. Because of the recent exponentialgrowth of the Internet, IPv4 is unable to satisfy the potential hugeincrease in the number of users or the geographical needs of the Internetexpansion. As a result, IPv4 address depletion is approaching quickly.Additionally, emerging applications such as Internet enabled PDAs, home area networks, mobile ad hocnetworks, IP wireless services and integrated IP telephony services require anew Internet protocol. 

 

The lifetimeof IPv4 has been extended using techniques such as address reuse with Network AddressTranslation or NET for short, Classless InterDomain Routing or CIDR andtemporary address assignments such as the Dynamic Host Configuration Protocolor DHCP. 

 

Thesetechniques appear to increase the address space and satisfy the traditionalserver client setup, but they fail to meet the requirements of true network anduser mobility. Applications need an increasing amount of bandwidth, while address translation has a performance impact onthe network equipment. 

 

Next theneed for always-on environments to be contactable prohibits these IP addressconversion pulling and temporary allocation techniques. Furthermore, the plug-and-play feature required byconsumer Internet appliances further increases the protocol requirements.Millions of new technology devices such as wireless phones, PDAs, cars and homeappliances will not be able to get global IPv4 addresses any longer. IPv4 willsoon reach the stage where choice has to be made between either newcapabilities or a larger network, but not both. In other words, we need a newversion of the IP protocol to provide new and enhanced features in addition tosolving the IP address exhaustion problem. That new version of IP is IPv6.