Combination Telephony Engine (presently Asterisk) PBX (in progress FreePBX) and AutoDialer (presently Vicidial) loaded onto Gentoo with detailed instructions. From blank machine to up and running in roughly 3 hours (mostly compile time, by advanced user)
OpenSMSC is ETSI GSM based realtime, distributed, highly available Short Message Service Center. It transfers short messages between mobile phones(MO and MT) over SS7 network and to applications(ESME) using open standard protocols like SMPP, HTTP & SOAP