At 06:54 01/01/01, Yu Ning wrote:
Recall the scarcity of IPv4 address, I wonder how this huge ip address demand was met in US ?
More than 50% of the IPv4 address space is not yet allocated, so they aren't so scarce. APNIC should be able to provide sufficient address space -- but you will need to give them a plan for your network to explain why you need so much address space.
In my mind, we have the following choices: 1. Build the MAN into a private address network, a class A network 10.x.x.x will be sufficient for most metropolitan. But the cons is: need PAT/NAT to access public Internet, and that leads to the potential performance bottleneck.
One could build the MAN using private addresses, but put customers in public global addresses, which would mean no need for NAT/PAT. As I said above, you should be able to get enough address space from APNIC by providing documentation for your planned network.
3. Build the MAN into a IPv6 network, and use address conversion at the interconnection point between v4 and v6. Just an idea, feeling that conversion efficiency between v4-v6 should be better than NAT/PAT, any support comments?
Conversion efficiency will not be any different and you would still need to get enough IPv6 address space. You should probably start by talking with APNIC about getting enough IPv4 address space to meet your planned network. That is the simplest and lowest cost approach. Best wishes, Ran Atkinson rja@extremenetworks.com Senior Scientist Extreme Networks Herndon, VA, USA