[VoiceOps] Open Source IP PBX

Hello, We have a potential customer who needs an opensource IP PBX. What is your suggestion as the customer have 350 extensions. If i have to build it on trixbox CE, what is the stable version. Regards, -- Siwangu Mgata Managing Director Sihebs Technologies Co. Ltd Ubungo Plaza, East Wing 1st Floor Tel: +255 22 2461445 Fax: +255 22 2461446 Mob: +255 713 480268 +255 782 888808 Email: svmgata at sihebs.co.tz Web: www.sihebs.co.tz