A protocol that specifies the compression/decompression method of audio, images, and data files sent or received via
A communication control protocol for Internet telephone that utilizes VoIP (which converts voice information to IP packets) and is equipped with func- 3 tions such as transfer and caller number display similar to telephone network compared to other protocols such as H.323.
❖Gatekeeper (VoIP gatekeeper)A gatekeeper manages devices connected to an IP network and converts alias telephone numbers to IP addresses and performs authentication functions. In addition, a gatekeeper governs band (transmission rate assignment) and ac- cess control.
❖Gateway (VoIP gateway)A gateway connecting a telephone network and IP network, it has functions such as protocol conversion for connect these different network, and also con- nects communication devices (telephones, facsimiles, etc.) to a LAN or other network.
❖SIP serverA SIP server mediates connection requests between devices connected to an IP network and is composed mainly of servers that have the following three functions:
•Proxy server: Issues requests and relays responses.
•Registrar server: Receives registration of a users positional information within an IP network.
•Redirect server: Used to inquire the destination of a request.
Notes on Using IP-Fax
•You cannot send to a
•You cannot use telephones on a LAN.
Functions not Available for IP-Fax Transmission
You can use the following functions with standard fax transmission, but not IP- Fax transmission:
• Batch transmission
• Manual dial
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