The unified communications manager is a toolset to assist you to use your PBX easily with your daily phone use.
RingCentral
https://www.voipgrid.nl
https://streammania.com
https://www.airbridgelabs.com
https://home.uchicago.edu/~sumitk
ReachUC
serge
Daniel Grimm
Mondago Ltd
Cuyler Stuwe
Samson IT BV
UC优视