The version of BE6K is 10.X , The vesion of CUCM is 10.5.X ,the desktop client voice sounds low, between mobile devices such as IPHONE ,sound is normal.
Please tell me what are the options can adjust.
yin liu,
I recommend you also post this to the Cisco Support Community for additional feedback and information.
Hope this helps.
Kelli Glass
Moderator for Cisco Customer Communities
i resolve the problem
because lic is trial.