Key Vendor - 3CX
3CX is a Unified Communications solution which includes an easy-to-use plug-and-play SIP IP PBX for Linux or Windows. Fully cloud hosted or on prem options exist.
Phone System
1) Standard - Subscription
Renewal2) Pro - Subscription
New License
Renewal
Upgrade3) Enterprise - Subscription
New License
Renewal
Upgrade4) SMB - Subscription
Renewal
Upgrade5) Hosted by 3CX - Subscription
New License
Upgrade