The telephony over IP (ToIP) is becoming a new trend in technology widely
used nowadays in almost all business sectors. Its concepts rely on transiting
the telephone communications through the IP network. Today, this technology is
deployed increasingly what the cause of emergence of companies is offering this
service as Switzernet. For several highly demanded destinations, recently fake
vendors appeared in the market offering voice termination but providing only
false answer supervision. The answered signal is returned immediately and calls
are being charged without being connected.