Kart Telephone companies in different countries use a variety of international telecoms routes to send traffic to each other. These can be legal (or 'white') routes or other arrangements the industry calls grey routes, special carrier arrangements, settlement by-pass and other euphemisms.A white route is, in the telecommunication business, is a route where both source and destination are legal termination. This is opposed to a black route, which is a route that is illegal in both ends. Also common in telecom (especially Voip) is the term grey route, which defines a route that is legal for one country or the party on one end, but illegal on the alternative end.Voice calls can be compressed and packaged into voice over Ip packets and sent over the public Internetor a more direct IP-bas data link, thus by-passing the conventional telephone routes into a country.A carrier receives calls in country A, turns them into IP packets using an IP gateway device and sends them over the Internet to another carrier or ISP in country B, which re-assembles the voice call and sends it out from a PBX. The cost to the carrier is the cost of a local call in the receiving country, not of an international call in the sending country.