OnSIP is #15 in Top 18 Business Phone systems
Virtual PBX Service For Any Business, provides virtual office connectivity, user friendly Web 2.0 management, free extension to extension calls, free internet to internet calls
OnSIP video
Positions in ratings
#15 in Top 18 Business Phone systems
Alternatives
The best alternatives to OnSIP are: RingCentral, 8x8, Nextiva