Between which two DTMF relay methods does the Expressway support interworking? (Choose two.)
Click on the arrows to vote for the correct answer
A. B. C. D. E.BE.
https://www.cisco.com/c/dam/en/us/td/docs/voice_ip_comm/expressway/admin_guide/Cisco-Expressway-Administrator-Guide-X12-6.pdfDTMF (Dual Tone Multi Frequency) is a signal that is sent from a phone's keypad to a telephone company's switching center or another device, such as an IP phone system, to indicate which number or symbol has been pressed. DTMF is commonly used for interactive voice response systems, automated attendants, and telephone banking. In the context of Cisco Collaboration Cloud and Edge Solutions, DTMF is used to pass user input during a call session between devices.
Cisco Expressway is an application that provides secure remote access to Cisco Unified Communications infrastructure. It supports interworking between different DTMF relay methods to enable calls between endpoints that use different DTMF relay methods.
The following are the DTMF relay methods that the Expressway supports interworking between:
RFC 2833: This is a standard protocol that encodes DTMF signals as RTP (Real-time Transport Protocol) events. RTP is used for transmitting audio and video over IP networks. RFC 2833 separates DTMF signals from voice signals and transmits them in separate RTP packets.
KPML (Key Press Markup Language): This is an XML-based protocol that is used to represent DTMF digits and other telephony events. KPML sends DTMF signals as part of an XML message that includes information about the call, such as the calling and called party numbers.
The Expressway supports interworking between these two DTMF relay methods, which means that calls between endpoints that use different DTMF relay methods can be successfully established. The Expressway also supports other DTMF relay methods, such as passthrough and H.245 user input indication, but interworking is not supported between them.