- Analog Voice Gateway – One Call Per Port
- Digital Voice Gateway – Multiple Calls Per Port
A lot of material already covered in CVOICE..
- H.323 Audio/Video – Peer to Peer (Doesn’t support QSIG)
- MGCP – Cisco primarily, Server-Client Model. CUCM can control the Gateway almost completely. CUCM dies and so does Voice Gateway!
- SIP – Universal VoIP standard (Connection to ITSP) – Peer to Peer