Jitter Buffer

Configure jitter buffer properties for Vocera SIP Telephony Gateway to prevent packet loss.

You can choose to employ a jitter buffer for the Vocera SIP Telephony Gateway to prevent lost packets. However, a jitter buffer may increase the audio latency for calls.

When you open the vstgproperties.txt file, you can set the following jitter buffer properties:

Property	Description
VGWUseRTPJitterBuffer	Enables a jitter buffer for RTP packets. By default, this is set to TRUE, meaning the jitter buffer is enabled.

RTPJitterMaxSize	Sets the maximum number of packets in the RTP jitter buffer. The default is .
RTPJitterPrefetch	The number of packets to pre-buffer. The default is 3.
VRTPJitterMaxSize	Sets the maximum number of packets in the RTP jitter buffer on voice side. The default is -1.
VRTPJitterPrefix	The number of packets to pre-buffer on voice side. The default is 3.

Note: The VRTPJitterMaxSize and the VRTPJitterPrefixvalues are applicable only if the VGWUseVRTPJitterBuffer is set to "true". Since the pjsip media framework is used, certain values are considered not valid and the application adjusts the values and logs when the value is adjusted.

PJSIP Jitter Buffer

The default PJSIP jitter buffer is an adaptive jitter buffer.

When VGWUserRTPJitterBuffer and VGWUseVRTPJitterBuffer values are set to false (or not set), the following PJSIP default values are used:

Property	Description
Jitter Buffer Max	Sets the maximum number of packets in the RTP jitter buffer. The default value is 25.
Jitter Buffer Init	Enables a jitter buffer for RTP packets. The default is 0 .
Jitter Buffer Prefetch Max	Sets the maximum prefetch value for jitter buffer. The default is 20.
Jitter Buffer Prefetch Min	Sets the minimum prefetch value for jitter buffer. The default is 1.