Please download the SIPSP-PBX Standard Edition to trial, It's a 20-user and one-year trial version, and Include the IP PBX and Voicemail, ACD features, It's very neat and easy to setup and maintence.
There are four softwares are avaliable to download and trial for VOIP Service Provider or ISP: Download SIPSP-PBX Advanced Edition Free Trial ( 100-user, 30-day trial ) Download SIPSP-Proxy Free Trial ( 100-user, 30-day trial ) Download SIPSP-IVR Free Trial ( beta, 120-day trial, Inlucde VoiceMail, Calling Card, ACD ) Download XYBS Billing Software Free Trial ( Not avaliable now )
For the online user manual, please go to the Wiki
