Configuring Ring Back Options

If your IP PBX does not support SIP early media or does not provide a ring back, you can configure Vocera SIP Telephony Gateway to use its own ring back tone by setting the following properties:

Table 1. Ring back options

Property

Description

VTGProvidedRingBackFilename

A ring back WAV file. Specify a location relative to the Vocera directory (<drive>:\vocera). The default file is \telephony\vgw\ringback.wav.

The ring back tone will be played in a cycle until SDP negotiation completes, so a small WAV file is recommended.

If you create a custom ring back file to use with Vocera SIP Telephony Gateway, the WAV file must have the following format:

Audio Format: 16 bit Monophonic
WAV PCM
Sampling Rate: 8000 samples/second

VTGProvideRingBack

Whether to provide a ring back tone from the Vocera SIP Telephony Gateway rather than relying on the IP PBX to provide it. The default is TRUE.

VTGBufferRingBackData

Whether to buffer the ring back data to avoid constant disk access. The default is TRUE.

VTGRingBackBufferSize

The buffer size to allocate for the ring back tone. For G.711 mu-law, 1 second of audio is 8000 bytes. The default buffer size is 48000 bytes, or 6 seconds of ring back tone. The maximum buffer size is 128000 bytes, or 16 seconds of ring back tone.

VTGRingBackStartAtBeginning

Whether to always start the ring back tone at the beginning of the file. The default is TRUE.

To start the ring back tone at the beginning, ring back data must be buffered (VTGBufferRingBackData = TRUE).