Out of buffer space

Hi,

Im using Asterisk 15 with opus support.

[opusXX]
type=opus
packet_loss=20
complexity=10
max_bandwidth=medium
signal=auto
application=voip
max_playback_rate=20000
bitrate=auto
cbr=1
fec=1
dtx=0

From time to time in log files i can find warning: Out of buffer space,
For such calls there is an echo in voice channel.

Is there any way to increase this buffer size? What can i do to solve this?

Best regards,