System for converting data based upon IPv4 into data based upon IPv6 to be transmitted over an IP switched network

1. A system for converting data packets based upon an IPv4 protocol into data packets based upon an IPv6 protocol to be transmitted over a multiple Virtual Private Network (VPN) infrastructure in a data transmission system comprising an IP switched network to which are connected a first workstation via a first Provider Edge (PE) device and a second workstation via a second PE device, said workstations operating with the IPv4 protocol whereas said IP switched network operates with the IPv6 protocol; said system comprising:

a first packet builder between said first workstation and said IP switched network for converting any data packet based upon the IPv4 protocol received from said first workstation and transmitted to said IP switched network into the IPv6 protocol;

a second packet builder between said IP switched network and said second workstation for converting saw data packet based upon the IPv6 protocol received from said IP switched network and transmitted to said second workstation into the IPv4 protocol; and

at least one server accessed by each of said first packet builder and said second packet builder for providing thereto information necessary to convert a data packet based upon the IPv4 protocol into a data packet based upon the IPv6 protocol; wherein any data packet that has been converted into the IPv6 protocol by one of said packet builders comprises a packet header comprising a PE field corresponding to a PE to be used either as source PE or destination PE and a VPN identification field related to an IPv4 address that was in said packet header before the conversion.

2. The system according to claim 1 , wherein any data packet that has been converted into the IPv6 protocol by one of said first packet builder and said second packet builder further includes a LOC identification field referring to a geographic location of a site and a HOST identification field referring to a workstation that transmitted said data packet.

3. A method for converting data packets based upon an IPv4 protocol into data packets based upon an IPv6 protocol to be transmitted over a Virtual Private Network (VPN) in a data transmission system comprising an IP switched network to which are connected a first workstation via a first Provider Edge (PE) device and a second PE device, said workstations operating with the IPv4 protocol whereas said IP switched network operates with the IPv6 protocol said method comprising;

converting any data packet based upon the IPv4 protocol into a data packet based upon the IPv6 protocol before transmitting the data packet to said IP switched network using information provided by an external server, and

converting any data packet based upon the IPv6 protocol provided by said IP switched network into a data packet based upon the IPv4 protocol before transmitting the data packet to said first or second workstation,

wherein any converted data packet comprises a packet header comprising a PE field corresponding to a PE to be used either as a source PE or as a destination PE and a VPN identification field related to an IPv4 address that was in said packet header before the conversion.

4. The method according to claim 3 , wherein any data packet that has been converted into the IPv6 protocol further includes a LOC identification field referring to a geographic location of a site and a HOST identification field referring to a workstation that has transmitted said data packet.