About Dtmf Detection On Ip-To-Isdn Calls - Cisco 3521 Administrator's Manual

Configuring Gateway Settings
The touch tone system uses pairs of tones to represent the various keys on the telephone. A "low tone"
and a "high tone" are associated with each button (0-9, *, and #). The low tones vary according to the
horizontal row in which the tone button is located in
column in which the tone is located. The local telephone company receives each pair of tones, decodes
the number dialed and makes the connection.
Table 3-9
697 Hz
770 Hz
852 Hz
941 Hz

About DTMF Detection on IP-to-ISDN Calls

The gateway passes incoming in-band DTMF signals to the ISDN-side endpoint unchanged. In addition,
you can configure the gateway to convert H.245 out-of-band DTMF signals from the IP side to in-band
signals on the ISDN side.
Figure 3-2
Administrator's Guide for Cisco IPVC 3521 BRI Gateway, Cisco IPVC 3526 PRI Gateway, and Cisco IPVC 3540 PRI Gateway
3-30
DTMF Tone Assignments
1209 Hz
1
GHI
4
PRS
7
*
Figure 3-2
IP-to-ISDN DTMF Processing
Translate DTMF from IP out-of-band (H.245) to ISDN in-band (ISDN G.711 only)
Disabled
IP
H.245
out-of-band
In-band
Gateway
Chapter 3
Table 3-9. The high tones correspond to the vertical
1336 Hz 1477 Hz
ABC DEF
2 3
JKL MNO
5 6
TUV WXY
8 9
oper #
0
illustrates IP-to-ISDN DTMF processing.
ISDN
Suppressed
out-of-band
In-band In-band
Configuring the Cisco IPVC 3500 Series Gateway
1633 Hz
A
B
C
D
Enabled
IP ISDN
H.245
Gateway
In-band
In-band
OL-7995-01