Quality of Service and performance characterization of IPv6 relative to IPv4

II.3 INTERNET PROTOCOL (IP)

Internet Protocol is the network layer for the TCP/IP protocol suite by which data is sent from one computer to another. IP like all network-layer protocols moves of information from the original source to the ultimate destination. This service is sometimes referred to «end-to-end packet delivery». This reliability of the service provided by IP is called «best-effort» which means that IP will try very hard to deliver a packet to destination, but IP makes guarantee that packet will arrive without error.^6(*)

II.3.1 IP Versions

There are currently two main versions of Internet Protocol IPv4 and IPv6.

II.3.1.1 IP version 4

IPv4 is the first version of the Internet Protocol to be widely deployed. IPv4 is the dominant network layer protocol on the Internet. It is the most IP widely used today. ^7(*)

The name was assigned as IPv4 because on any IP header, the first 4 bits are reserved for protocol version. Thus the first version of IP had been assigned as IPv4.

II.3.1.2 IP version 5

IPv5 was assigned to an experimental protocol called ST2 (Internet STream protocol, version 2).

IPv5 was not a successor to IPv4, but an experimental flow-oriented streaming protocol intended to support video and audio. It was discussed as a successor to IPv4, but it has never been introduced for public usage.^8(*)

II.3.1.3 IP version 6

IPv6 is short for "Internet Protocol Version 6". IPv6 is the "next generation" IP protocol designed by the IETF to replace the version IPv4 (or IP only), the Internet protocol that is predominantly deployed and extensively used throughout the world.^9(*)

Invented by Steve Deering ^10(*)and Craig Mudge at Xerox`s Palo Alto Research Center, IPv6 was adopted by the Internet Engineering Task Force in 1994, when it was called "IP next generation" (IPng).

The name IPv6 and not IPv5 as successor for IPv4 is because the number 5: is reserved for the ST2. The next free number was 6. Hence IPv6 was born.^11(*)

II.3.1.4 IP version 9

IPv9 is a relatively unheard-of version of the Internet Protocol attributed to China. The IP version 9 numbers has not been allocated for this protocol by the Internet Assigned Numbers Authority.

On June 25, 2004, an announcement was made at the New Generation Internet Ten-Digit Network Industrialization & Development Seminar at Zhejiang University, that the protocol had been «formally adapted and popularized into the civil and commercial sectors of China».

The validity of any meaningful implementation of IPv9 is in question. It has been described as a protocol similar to IPv6, but with a 256 bit addresses space instead of IPv6's 128 bit address space. Chinese experts have suggested that the required edge router translation protocols would not be worth the questionable benefit of expanding the address space further.^12(*)

* ⁶ http://en.wikipedia.org/wiki/Internet_protocols (May 02, 2006)

* ⁷ http://en.wikipedia.org/wiki/IPv4 (May 12, 2006)

* ⁸ http://en.wikipedia.org/wiki/IPv5 (May 12, 2006)

* ⁹ http://www.ipv6.org/ (May 12, 2006)

* ¹⁰ http://en.wikipedia.org/wiki/Steve_Deering (October 01, 2006)

* ¹¹ http://mirrors.bieringer.de/Linux+IPv6-HOWTO/x459.html (June 09, 2006)

* ¹² http://en.wikipedia.org/wiki/IPv9 (May 12, 2006)