VoIP profile configuration task list
574
SmartWare Software Configuration Guide
47 • VoIP profile configuration
Configuring DTMF relay
Dual tone multi-frequency (DTMF) tones are usually transported accurately in band when using high bit-rate
voice codecs such as G.711. Low bit-rate codecs such as G.729 and G.723.1 are highly optimized for voice pat-
terns and tend to distort DTMF tones. The
dtmf relay
command solves the problem of DTMF distortion by
transporting DTMF tones out-of-band or separate from the encoded voice stream as shown in
figure 2
. H.323
signals the DTMF tones as H.245 user input indications, SIP uses a mechanism of RTP to reliably transport
tones (according to RFC2833).
Figure 2. DTMF Relay
This procedure describes how to configure DTMF relay
Mode:
Profile VoIP
Configuring RTP payload types
If you are using DTMF relay with SIP, the DTMF digits are transported in RTP packets with a special payload
type. The default value for this payload type can be configured in the profile VoIP.
Procedure:
Configure RTP NTE payload type
Mode:
Profile VoIP
Step Command
Purpose
1
node
(pf-voip)[
pf-name
]#dtmf-relay
{default|rtp|signaling}
Define how DTMF digits shall be transmitted.
You can configure the SIP gateway to send
DTMF digits either by using the SIP INFO
method or in the RTP stream (RFC 2833). The
gateway will always receive both types of
DTMF digits. The command has currently no
effect for H.323 calls.
Step
Command
Purpose
1
node
(pf-voip)[
name
]#rtp payload-
type nte
payload-type
Specifies the RTP payload-type for named tone
events NTE (RFC2833). Default: 101.
encoder
decoder
payload
Signalling of dtmf tones
Generates dtmf tones
Detects dtmf tones
Содержание SmartNode Series
Страница 250: ...RIP configuration task list 250 SmartWare Software Configuration Guide 23 RIP configuration rip enabled ...
Страница 635: ...635 Appendix A Terms and definitions Chapter contents Introduction 636 SmartWare architecture terms and definitions 636 ...
Страница 641: ...641 Appendix B Mode summary Chapter contents Introduction 642 ...
Страница 648: ...648 Appendix D Internetworking terms acronyms Chapter contents Abbreviations 649 ...
Страница 653: ...653 Appendix E Used IP ports available voice codecs Chapter contents Used IP ports 654 Available voice codecs 655 ...