Which DTMF relay method is advertised when the originat…

Refer to the exhibit.
Which DTMF relay method is advertised when the originating SIP gateway sends an INVITE
message with a Call-Info header shown?

A.
RFC 2833

B.
SIP INFO

C.
SIP NOTIFY

D.
SIP KPML

E.
In-band audio

Explanation:
You can develop user-specific applications that reside on your network entity and have the ability
to subscribe for event services supported by the IMG. If the network entity wants the ability to
detect an entered DTMF digit (only telephone event of “###†are currently supported) from the

TDM-side of a call to the IP side of a call, the entity can subscribe to the IMG for these events and
receive SIP NOTIFY events containing the digit event.