An ITSP (Internet Telephony Service Provider) offers an Internet data service for making telephone calls using VoIP (Voice over IP) technology. Most ITSPs use SIP, H.323, or IAX (although H.323 use is declining)[citation needed] for transmitting telephone calls as IP data packets. Customers may use traditional telephones with an analog telephony adapter (ATA) providing RJ11 to Ethernet connection.What are two benefits of using an ITSP for long distance telephony services?

A.
The circuits are dedicated only to voice

B.
Connection to an ITSP is only available in full T1/E1/PRI circuit quantities.

C.
Connection to an ITSP is very granular and can provision from 1 to 100 simultaneous calls.

D.
Connection to an ITSP allows you to use the bandwidth that is guaranteed to the voice traffic for data when voice is not using the bandwidth.