FTS users pay nothing but internet fees for calls, with the device costing only US$150 per set.

The system uses the Voice over Internet Protocol telephony (VoIP), invented during the 1990s.

Some considered it the realization of the Network Voice Protocol invented by Danny Cohen from Southern California University in 1973.

Ho Quoc Sy, a member of the group, said that they created the telephone for their relatives and friends to easily communicate with those living overseas to skirt long distance phone costs.

Later on the group contacted several partners in Vietnam to produce the phone sets on a large scale.

More information on the product can be acquired at www.freetelsystem.com.

Reported by My Quyen – Translated by Thanh Tuan