An Engineer is configuring a CUBE interoperability with a SIP Service Provider. What are the three different ways Mid -Call Re – Invites function to ensure smooth interoperability of supplementary services? (Choose three.)
A. provides early offer to delay offer codec change in 200 OK message
B. provides support for media flow ?around in early offer forced call flows
C. converts a delayed offer to an early offer
D. allows interoperability for video ?related features
E. allows pass through of mid- call signalling on media change
F. blocks all mid- call signalling for specific SIP trunk
C, E, F
The purpose of Mid-call Re-INVITE Consumption is to ensure smooth interoperability of supplementary services (like audio hold, resume and call transfer) by consuming unnecessary re-invites (mid-call signaling) locally.
This can be done in three different ways:
— Converting a delayed offer to an early offer—
— Passthrough of mid-call signaling regarding media change—Mid-call signaling is passed through only when bidirectional media like T.38 or video is added.
— Blocking all mid-call signaling for a specific SIP trunk.
https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube_sip/configuration/xe-3s/cube-sip-xe-3s-book/voi-cube-midcall-reinvite.html