VoIP - PSTN gateway
Connect the existing PBX to alternative VoIP providers.
Yate as a PBX
How to use Yate as a PBX depending on the features you need.
H323 To SIP Signalling Proxy
Yate is proxying between the H.323 and SIP protocols.
SIP SBC - session border controller
PHP - External modules
YAYPM- Yet Another Python Module
SS7 - Initiation