I don't know what you mean by nodes. But most routers permit 4 wired connections and, I don;t know how many, wi-fi connections.
When you get ONE connection from your ISP, all those connected devices can use the router at the same time. Because on request from a computer, the routers issues Local Area Network (LAN) IP numbers. The external IP is just one for all. Router keeps track of who is doing what and which packets to be delivered to which computer. It uses MAC address of the adapters for the ethernet packets, so it knows who is who.
Long ago ISPs didn't allow this sort of thing. They wanted you to pay for each device. Then they discovered a shortage of IP addresses and said, hey, we can allow all that stuff and still use just one IP
Anyway, for home users, typical internal IPs are usually something like 192.168.1.0/255.255.255.0 which means 254 possible IPs out of the router. (.0 and .255 are reserved, .255 is used for broadcasting). Other non-routable ranges are 10.x.x.x and 176.x.x.x. Non-routeable means those IPs are not visible on the internet. They go no further than the first hop router. I can't connect to your 192.168.1.105. Unless I'm a very skilled hacker
Take a look at these:
If by "nodes" you mean other groups of computers behind other routers - then yes, it'll still work so long as the wiring and the setup in all routers is done properly.
Edited by tos226, 09 October 2011 - 08:56 PM.