- One telephone with several numbers: each subscriber can be assigned with 3 different numbers to access into different service provider network; each number can realize DOD1+DID.

- Keep subscribers former habit unchanged: The subscriber is directly corresponding with the line, by ringing extension for incoming call.

- Long distance call and special direction call intelligently take the bypass: save the cost greatly by number analyzing & economical route taking.

- Blind spots be fixed intelligently.

- Abundant programmable control capacity.

- High reliability: it will switch to direct-line status automatically upon system error.

- Its a more economical, more convenient, more reliable communication mode than virtual network + IP telephone card + direct dialing.