IP Convergence: Beyond VoIP, Beyond Cost Savings

Today the internet is largely defined by a protocol called IPv4 , the forth version of IP and the 1st that was widely deployed.

IPv4 uses 32 bits of binary information to represent a unique IP address, which equals a maximum value of (2 to the power of 32) or just over 4 billion (actually 4,294,967,295).

Compared to IPv4 predecessor’s of using 16 bits of binary information to represent a unique IP address, which equals a maximum value of (2 to the power of 16) or 65,535.

Doubling the amount of bits for an IP address from 16 to 32 resulted in an increase of 5 orders of magnitude.

IPv6 uses 128 bits of binary information to represent a unique IP address, which equals a maximum value of (2 to the power of 128 ) or 340-undecillion or 3.4E38 billion (actually 340,282,366,920,938,000,000,000,000,000,000,000,000 this number is larger than the number of stars that are known to astronomer’s today!!).

Increasing the amount of bits for an IP address from 32 to 128 results in an increase of 29 orders of magnitude against the current maximum in IPv4 of just over 4 billion.

The number 4 billion is quite large considering the world’s population is just over 6 billion , so what is all of the fuss about?

Well, today’s internet relies on a number Request For Comment (RFCs) that help manage a demand that could be larger than the actual size of the number of available IP addresses, such as:
- RFC 1918 defines a group of IPv4 addresses that are consider private and not routable over the internet such as 10.x.x.x , 192.168.x.x or 172.16.0.0 with a netmask of 172.31.255.255.

- RFC 1613 defines the process, terminology and consideration of using Network Address Translation (NAT) that helps manage mapping of an IP address to many (or vise versa). NAT is very useful within an Enterprise that uses RFC 1918 (private non-routable internet addresses).

- RFC 2131 defining the protocol and process by which an IP end point (either public or private) can request a temporary IP address known as DHCP. This grew out of dial-up internet where users needed an IP address only for that specific session.

Although there are a number of RFCs that help us manage the current IPv4 pool of addresses across the internet or within an intranet, they create complexity and will not address the forecasted demand of adding converged services and devices needing IP addresses to just about everything.

What does this mean to you?
- Consider the increased deployment of VoIP, both RFC 1918 and RFC 1613 increase the complexity and reliability of reaching a VoIP end point as it moves from network to network.

- An end point that understands a IPv4 address (32 bit) will not understand a IPv6 address, the IPv4 end point doesn’t have enough fingers and toes to count.

- But an end point that understands a IPv6 address (128 bit) will understand a IPv4 address.

- That the number of available unique addresses in IPv6 will last , at least, our life time and our children's – unless we start assigning a IPv6 address to each star.

It’s a fact the it will take sometime for IPv6 to become as largely deployed as it’s predecessor IPv4, however during this transition it’s important to look at a network provider that can provide dual stack support on internet access so that the access router understands both IPv4 and IPv6 addressing.