| A | B |
|---|
| Call control | The mechanics of setting up and ending a telephone call |
| Voice transmission | sends the sounds across the network, this in- |
| Out of Band | The signals used to provide connection/call services do not |
| H.323 | A set of protocols used by VoIP to establish and manage telephone calls. This set of protocols are controlled by the International Telecommunication Union (ITU) |
| SIP | a signaling protocol for Internet conferencing, |
| Terminals | computers running softphone software and VoIP telephones using the H.323 protocol |
| Gateways | The bridge to the PSTN |
| MCU | supports conferences between three or more endpoints. Conferencing can be audio, video, or data. |
| SIP URI | sip:bobj@abc.com |
