Networking All-in-One For Dummies. Doug Lowe

(that is, the local network), where the network can then deliver the packet to the original requestor (the user at 192.168.0.50).

      So, what happens if two or more users have requests to the same web server at the same time? NAT is able to figure it out because each of those requests has a different temporary port number. For example, the user in the preceding example got port 42003. Another user sending a request to the same web server might get port 43859. When the reply comes back from the web server, NAT looks at the destination port to determine which local computer should receive the reply.