Lee Howard wrote:
So, all we need is NAT44 CPE, which only uses a reserved block of ports, which is (semi) statically configured by ISP operated gateway.
How would you route from the provider edge?
If CPE A has 192.0.2.15 port 1000-2999
and CPE B has 192.0.2.15 port 3000-4999,
Oops,I concentrated on minimizing logging and forgot about that. Sorry. I assume COE gateway also act as NAT44, though no port translation necessary there.
how does your BRAS or CMTS or edge router know whether to forward a packet to A or B?
Incoming packets are forwarded to A or B by private IP address of A or B based on source port. Depending on configuration, some port may always accept incoming packets and other port accept incoming packets only when the port is used by an outgoing connection.
Pro: Stateless, very efficient, no IPv6 necessary Con: No current CPE support.
As for protocol, assuming port mapping on UPnP gateway is statically configured by ISPs not changable from CPE side, GetListOfPortMappings() of UPnP should be useful for CPEs to know range of ports to be used by them.
Do CPEs do this now, or is this another feature to ask vendors for?
I think there is no current CPE support. COE supporting GetListOfPortMappings() may not exist, either. Masataka Ohta