VOIP guru needed

I am looking to hire for a 2 hour phone conversation (with a candidate fluent in conversational English), a programmer/consultant that considers themselves well versed in the following, and is willing to answer questions and educate me about these topics: IAX - asterisk specific VOIP protocol [login to view URL] SIP - Session Initiation Protocol (a more generic IP communication protocol, pretty hip with MS) H.323 - even older VOIP protocol VOIP IVR PSTN - Publicaly Switched Telephone Network POTS - Plain Old Telephone Service PBX - private branch exchange ## Deliverables 1) 2 hour Q&A phone conversation for the topics described above. ## Platform Linux (and other appropriate VOIP platforms)