For s SIP to SIP call flow, when does Cisco Unified Border Element require transcoding resources for DTMF?
A. interworking between an OOB method and RFC2833 for flow-around calls
B. interworking between h245-signal and rtp-nte
C. interworking between an OOB method and RFC2833 for flow-through calls
D. interworking between h245-alpha numeric and sip-kpml
