IPv6 Provides More IP Address
IPv6 addresses the main problem of IPv4, that is, the exhaustion of addresses to connect computers or host in a packet-switched network. IPv6 has a very large address space and consists of 128 bits as compared to 32 bits in IPv4. Therefore, it is now possible to support 2^128 unique IP addresses, a substantial increase in number of computers that can be addressed with the help of IPv6 addressing scheme.
In addition, this addressing scheme will also eliminate the need of NAT (network address translation) that causes several networking problems (such as hiding multiple hosts behind pool of IP addresses) in end-to-end nature of the Internet.http://ipv6.com/articles/general/ipv6-the-next-generation-internet.htm
IPv6 Provides More Features
IPV6 brings quality of service that is required for several new applications such as IP telephony, video/audio, interactive games or ecommerce. Whereas IPv4 is a best effort service, IPv6 ensures QoS, a set of service requirements to deliver performance guarantee while transporting traffic over the network.
For networking traffic, the quality refers to data loss, latency (jitter) or bandwidth. In order to implement QOS marking, IPv6 provides a traffic-class field (8 bits) in the IPv6 header. It also has a 20-bit flow label. Mobile IPv6 ensures transport layer connection survivability and allows a computer or a host to remain reachable regardless of its location in an IPv6 network and, in effect, ensures transport layer connection survivability.
With the help of Mobile IPv6, even though the mobile node changes locations and addresses, the existing connections through which the mobile node is communicating are maintained. To accomplish this, connections to mobile nodes are made with a specific address that is always assigned to the mobile node, and through which the mobile node is always reachable. This feature is documented in RFC 3775.http://ipv6.com/articles/general/ipv6-the-next-generation-internet.htm