A Cisco voice gateway is configured to use a sip-kpml DTMF relay in global settings. A new SIP dial peer is configured for a third-party application that only supports an in-band DTMF relay. Which…

`dtmf-relay sip-info` is a SIP-specific out-of-band DTMF relay method, which would not meet the requirement for an in-band DTMF relay.

`no dtmf-relay sip-kpml` would remove the global setting from the dial peer, but it would not explicitly configure the required in-band DTMF relay.

`dtmf-relay sip-notify` is a SIP-specific out-of-band DTMF relay method, which would not meet the requirement for an in-band DTMF relay.

The `dtmf-relay rtp-nte` command configures the dial peer to use RTP-NTE (RFC 2833), which is a standardized method for in-band DTMF relay. This setting ensures that the third-party application, which only supports in-band DTMF, can correctly interpret the dual-tone multi-frequency signals transmitted over the call, despite a different global DTMF relay configuration.