1. Existing architecture GSM network GSM network IMS Voicemail GSM users migration ?

2. Use Case: John Smith manager John Smith is a successful manager. Being abused by sales agents’ calls, he decides to block them. This week, he is going to the beach to relax, so calls are managed by a voicemail system. However, he doesn’t want to miss lucrative business opportunities by not accepting his VIP clients, their calls are redirected to his secretary. His family is important for him, so he always accepts their calls.

3. Use Case diagram blocking calls forwarding calls voicemail system accepting calls group management privacy management

4. Telephone calls IMS PSTN GW IMS client traditional telephony

5. Call forwarding IMS PSTN GW IMS client traditional telephony Call Manager

6. Voicemail IMS PSTN GW IMS client traditional telephony Call Manager Voicemail

7. Web Interface IMS PSTN GW IMS client traditional telephony Call Manager Voicemail DB Web Web Service Web browser Streaming server