VoIP Configuration

You can configure the following settings on the Advanced Configuration VoIP tab for the voice server.

Dual Tone Multi-Frequency (DTMF) Settings

Dual Tone Multi-Frequency (DTMF) is a system used by touch-tone telephones in which a specific frequency consisting of two separate tones is assigned to each key so that it can easily be identified by a microprocessor.

To Configure the DTMF Settings for the Voice Server:

1.On the Management Portal menu window, click System Configuration > Voice Server > Advanced Configuration. The Voice Server Advanced Configuration page opens.

2.Click the VoIP tab.

3.Complete the RFC2833 DTMF Payload field, which configures the payload type to use for out-of-band DTMF detection and generation. Most deployments can use the default payload type, which is 101. Change this value only if Ivanti Voice might interface with a gateway that requires the payload to be different.

4.Click the Update and Commit Changes buttons to enact your changes.

SIP Session Timer Setting

Ivanti Voice detects SIP sessions that have lost connection instead of properly closing the connection. For example, if a caller unplugs the network cable from a SIP-enabled phone while on a call with the voice application, Ivanti Voice detects the session is over, even though Ivanti Voice does not receive the message indicating the caller hung-up the handset, which typically closes the SIP session. Ivanti Voice achieves this detection by sending a refresh request for every call on every half interval you specify. If there is no response from the remote side, Ivanti Voice considers the connection lost and releases all resources connected to the call. Ivanti Voice also notifies the voice application about the disconnected call.

Ivanti Voice sends refresh requests when half the session interval expires, as recommended by the SIP standard. Waiting for the full interval to expire is risky, as the remote endpoint may also keep track of that session and delay the refresh request if network problems occur. This can inadvertently cause the remote end to terminate the SIP session.

To Specify the Interval at which the Voice Server Checks for an Offline SIP Phone:

1.On the Management Portal menu window, click System Configuration > Voice Server > Advanced Configuration. The Voice Server Advanced Configuration page opens.

2.Click the VoIP tab.

3.In the SIP Session Timer field, specify the number of seconds you want Ivanti Voice to wait between sending refresh requests. Ivanti recommends setting this value to 1800 seconds. Do not set this value to less than 90 seconds, as the SIP standard explicitly warns that shorter intervals place excessive loads on the network.

4.Click the Update and Commit Changes buttons to enact your changes.