3CX PBX in the Cloud
1 year FREE - no ties!
google cloud platform
3CX
Zero Admin
With the new Dashboard
3CX
Bulletproof Security
With SSL certs and NGINX
3CX
Install on $200 Appliance
Intel MiniPC architecture
3CX
New, Intuitive Windows Client
More themes, more UC
3CX
More CRM Integrations
Scripting Interface to add your own
3CX
Improved Integrated Web Conferencing
iOS and Android apps included
3CX
Run On-Premise or in the Cloud
Google, OVH, Windows & Linux
Fast & easy call management
With the 3CX Web Client

VOIP info의 유용한 소스

Wikipedia에서 VOIP에 관한 유용한 기사를 찾아볼 수 있습니다. 먼저

http://en.wikipedia.org/wiki/Voice_over_IP

에서 VOIP에 관한 설명부터 보는 것이 좋습니다.