Which of the following are functions that are often provided by an ITSP but are not typically provided by the PSTN？（）
A: QoS
B: call setup and teardown
C: call routing
D: call supervision
E: audio signal compressio
A: QoS
B: call setup and teardown
C: call routing
D: call supervision
E: audio signal compressio
举一反三
- Which of the following are functions that are often provided by an ITSP but are not typically provided by the PSTN？（） A: QoS B: call setup and teardown C: call routing D: call supervision E: audio signal compression
- Wake-up call service is usually provided by the ___department. A: Guest Service Center B: F&B C: Finance D: Engineering
- Which device is normally used to translate telephone numbers or names to IP addresses for call routing in an H.323 network？ （） A: call agent B: IP phone C: multipoint control unit D: gatekeeper
- When making preparations for a business call, which of the following is not right?
- 号召 A: call for B: call off C: call on D: call by