Which two statements are true about voice ports on a router？ （）

• A、 Calls to the PSTN can be made via the use of FXO or T1/E1 trunk ports.
• B、 Calls to the PSTN can be made via FXS or T1/E1 trunk ports.
• C、 Analog and IP phones can be connected to the VoIP network via FXO or T1/E1 trunk ports.
• D、 Calls between analog phones that are attached to the FXS ports in a VoIP network can be completely processed by voice-enabled routers.