Modern international networks have evolved from point-to-point networks with single routes interconnecting ROAs of different countries to more complex networks with multiple routes between countries. The number of interconnections between countries has increased due to growth in the number of ROAs, the ability to transit calls through intermediate countries, and an increase in the flexibility in routing mechanisms supported by modern switching equipment. This is illustrated by the following figure where we see three routes between two countries. In this example, two routes are direct routes, which may use the same or different technology, and the third is a non-direct or transit route.