CHAPTER 2 |
37
INSTALLATION AND CONFIGURATION
SIP and DTMF
The VX uses standard SIP techniques for dialing. A SIP call setup message containing the number is sent to the IP network. The
gateway to the PSTN generates the DTMF (Dual Tone Multi-Frequency) audio signal that the PSTN uses to direct the call.
The VX generates DTMF audio just as sound effects really. Listeners expect phones to sound like phones. DTMF tones “played”
for the audience are not the actual digits dialed and some are not even “real” DTMF digits, but sound like them. This is so that
if a number is dialed “live, on the air” nobody can get the telephone number being dialed by recording the program audio or
“decoding” the tones heard on the air.
There is sometimes the need to send DTMF to the PSTN after a call is connected, such as for automated attendant systems or
“dial up” remote control systems. In this case the VX sends a special SIP message that tells the PSTN gateway to generate the
corresponding audio DTMF tones, according to the standard specified in the IETF (Internet Engineering task force) RFC2833.
Information Pages
These pages provide some insight to the inner-workings of the VX for troubleshooting and management purposes.
Studios Information Menu and Pages
The studio Information Menu provides a list of Studios, Fixed and
Selectable Channels handled by that Studio, devices (VSets and other
controllers) connected to the Studio and the Show that is logged into the
Studio. Clicking on a Studio Name will take you to the Information page
for the studio.
The Studio’s information page will repeat the details provided by the
Studio Information list and provides more information about the Fixed
and/or Selectable channels, POH, the IP address of the Devices connected
how many calls are currently active or on hold, and the status of the Line
positions. This is really helpful if you are having trouble with lines on the
VSet. You can also navigate to the Studio or Show configuration from here
by clicking the blue links at the top of the information page.
The status of the lines in Studio A (Show 1) say, “OK (Registered)”
meaning they are successfully registered to the SIP server and are ready to
make or take calls.