VNC: dynamic IP for WAN connections

Connecting to an office PC from home?
I don't have a Static IP for my WAN Connections
Local ips( Local Area Network LAN)
10.0.0.0 - 10.255.255.255 16,777,216(ips avaliable Class A )
172.16.0.0 - 172.31.255.255 1,048,5769(ips avaliable Class B)
169.254.0.0 - 169.254.255.255 65,5369(ipsavaliable Class B)
192.168.0.0 - 192.168.255.255 65,536(ips availiable Class C)
More information on IPs at http://en.wikipedia.org/wiki/Private_IP_address
Private ips are not able to be used via the internet they will not work they are considered Private IP's
Your (Wide Area Network WAN) address it is an ip that is used to communicate with the internet it is the address that comes from your internet service provider (ISP)
To find out what your your wan ip address is
http://www.whatsmyip.org/
The problem comes in that this address is mostly dynamic (changes all the time) in this case you would need the dyndns service..
Most Routers will support the use of a Dynamic Domain Name Service that
will let you connect via a hostname instead of an ip address. The routers configuration varies so much that is almost impossible to create a step by step document for this feature.
There Are Serval Free Dyndns sites available
www.dyndns.org
www.no-ip.com
basically you need to create an account with one of the service providers then program the router to send the update request when its ip changes
Most routers only need to know the following
The web address of the dyndns account
The username of the account
The password of the account