Netopia R3100 用户手册

A filter set acts like a team of customs inspectors. Each filter is an inspector through which incoming and 
outgoing packages must pass. The inspectors work as a team, but each inspects ever y package individually. 

Each inspector has a specific task. One inspector’s task may be to examine the destination address of all 
outgoing packages. That inspector looks for a cer tain destination—which could be as specific as a street 
address or as broad as an entire countr y—and checks each package’s destination address to see if it matches 
that destination.

Continuing the customs inspectors analogy, imagine the inspectors lined up to examine a package. If the 
package matches the first inspector’s criteria, the package is either rejected or passed on to its destination, 
depending on the first inspector’s par ticular orders. In this case, the package is never seen by the remaining 
inspectors.